TY - JOUR TI - Spreading resistance effects in tunneling spectroscopy of α-RuCl3 and Ir0.5Ru0.5Cl3 AU - Frick, Jordan R. AU - Sridhar, Samanvitha AU - Khansari, Ario AU - Comstock, Andrew H. AU - Norman, Elizabeth AU - O'Donnell, Shaun AU - Maggard, Paul A. AU - Sun, Dali AU - Dougherty, Daniel B. T2 - PHYSICAL REVIEW B AB - The Mott insulating state is the progenitor of many interesting quantum phases of matter including the famous high-temperature superconductors and quantum spin liquids. A recent candidate for novel spin liquid phenomena is $\ensuremath{\alpha}\text{\ensuremath{-}}{\mathrm{RuCl}}_{3}$, a layered honeycomb Mott insulator whose electronic structure has been a source of mystery. In particular, scanning tunneling spectroscopy has indicated a Mott gap in $\ensuremath{\alpha}\text{\ensuremath{-}}{\mathrm{RuCl}}_{3}$ that is much lower than the 2-eV value observed in photoemission measurements. Here, we show that the origin of this discrepancy is a spreading resistance artifact associated with tunneling into highly resistive materials by comparing with prior experiments and numerical modeling. A similar phenomenon is also observed in a substitutional alloy, ${\mathrm{Ir}}_{0.5}{\mathrm{Ru}}_{0.5}{\mathrm{Cl}}_{3}$, that has a higher resistivity than the parent compound. While the tunneling measurements cannot be used to accurately measure the sample density of states for these materials, we can take advantage of the spreading resistance sensitivity to quantify the anisotropic resistivity of these layered materials and connect to previous macroscopic transport observations. DA - 2023/12/12/ PY - 2023/12/12/ DO - 10.1103/PhysRevB.108.245410 VL - 108 IS - 24 SP - SN - 2469-9969 ER - TY - JOUR TI - 3-Component Approach to 1,5-Dihydro-2H-pyrrol-2-one Heterocycles AU - Massaro, Nicholas P. AU - Pierce, Joshua G. T2 - ORGANIC SYNTHESES DA - 2023/// PY - 2023/// DO - 10.15227/orgsyn.100.0418 VL - 100 SP - 418-+ SN - 2333-3553 ER - TY - JOUR TI - Current understanding of lignan biosynthesis AU - Canty, Nicholas Koenig AU - Chang, Wei-chen T2 - ARKIVOC DA - 2023/// PY - 2023/// DO - 10.24820/ark.5550190.p012.006 SP - SN - 1551-7012 KW - Lignin KW - biosynthesis KW - podophyllotoxin KW - enzyme transformation ER - TY - JOUR TI - Influence of Al2O3 Overlayers on Intermolecular Interactions between Metal Oxide Bound Molecules AU - Knorr, Erica S. AU - Basquill, Cody T. AU - Bertini, Isabella AU - Arcidiacono, Ashley AU - Beery, Drake AU - Wheeler, Jonathan P. AU - Winfred, Joseph Sundar Raaj Vellore AU - Strouse, Geoffrey F. AU - Hanson, Kenneth T2 - Molecules AB - Intermolecular interactions on inorganic substrates can have a critical impact on the electrochemical and photophysical properties of the materials and subsequent performance in hybrid electronics. Critical to the intentional formation or inhibition of these processes is controlling interactions between molecules on a surface. In this report, we investigated the impact of surface loading and atomic-layer-deposited Al2O3 overlayers on the intermolecular interactions of a ZrO2-bound anthracene derivative as probed by the photophysical properties of the interface. While surface loading density had no impact on the absorption spectra of the films, there was an increase in excimer features with surface loading as observed by both emission and transient absorption. The addition of ALD overlayers of Al2O3 resulted in a decrease in excimer formation, but the emission and transient absorption spectra were still dominated by excimer features. These results suggest that ALD may provide a post-surface loading means of influencing such intermolecular interactions. DA - 2023/6/17/ PY - 2023/6/17/ DO - 10.3390/molecules28124835 VL - 28 IS - 12 SP - 4835 UR - http://dx.doi.org/10.3390/molecules28124835 ER - TY - JOUR TI - Excision of a Protein-Derived Amine for p-Aminobenzoate Assembly by the Self-Sacrificial Heterobimetallic Protein CADD AU - Phan, Han N. AU - Manley, Olivia M. AU - Skirboll, Sydney S. AU - Cha, Lide AU - Hilovsky, Dalton AU - Chang, Wei-chen AU - Thompson, Peter M. AU - Liu, Xiaojing AU - Makris, Thomas M. T2 - BIOCHEMISTRY AB - Chlamydia protein associating with death domains (CADD), the founding member of a recently discovered class of nonheme dimetal enzymes termed hemeoxygenase-like dimetaloxidases (HDOs), plays an indispensable role in pathogen survival. CADD orchestrates the biosynthesis of p-aminobenzoic acid (pABA) for integration into folate via the self-sacrificial excision of a protein-derived tyrosine (Tyr27) and several additional processing steps, the nature and timing of which have yet to be fully clarified. Nuclear magnetic resonance (NMR) and proteomics approaches reveal the source and probable timing of amine installation by a neighboring lysine (Lys152). Turnover studies using limiting O2 have identified a para-aminobenzaldehyde (pABCHO) metabolic intermediate that is formed on the path to pABA formation. The use of pABCHO and other probe substrates shows that the heterobimetallic Fe/Mn form of the enzyme is capable of oxygen insertion to generate the pABA-carboxylate. DA - 2023/11/7/ PY - 2023/11/7/ DO - 10.1021/acs.biochem.3c00406 VL - 62 IS - 22 SP - 3276-3282 SN - 1520-4995 ER - TY - JOUR TI - Aptamer-Based Fentanyl Detection in Biological Fluids AU - Canoura, Juan AU - Liu, Yingzhu AU - Alkhamis, Obtin AU - Xiao, Yi T2 - ANALYTICAL CHEMISTRY AB - Fentanyl is a widely abused analgesic and anesthetic drug with a narrow therapeutic window that creates easy opportunities for overdose and death. Rapid, accurate, and sensitive fentanyl detection in biosamples is crucial for therapeutic drug monitoring and overdose diagnosis. Unfortunately, current methods are limited to either sophisticated laboratory-based tests or antibody-based immunoassays, which are prone to false results and are mainly used with urine samples. Here, we have utilized library-immobilized SELEX to isolate new aptamers─nucleic acid–based bioreceptors that are well-suited for biosensing─that can specifically bind fentanyl under physiological conditions. We isolated multiple aptamers with nanomolar affinity and excellent specificity against dozens of interferents and incorporated one of these into an electrochemical aptamer-based sensor that can rapidly detect fentanyl at clinically relevant concentrations in 50% diluted serum, urine, and saliva. Given the excellent performance of these sensors, we believe that they could serve as the basis for point-of-care devices for monitoring fentanyl during medical procedures and determining fentanyl overdose. DA - 2023/11/30/ PY - 2023/11/30/ DO - 10.1021/acs.analchem.3c04104 VL - 95 IS - 49 SP - 18258-18267 SN - 1520-6882 ER - TY - JOUR TI - Effects of temperature, reaction time, atmosphere, and catalyst on hydrothermal liquefaction of Chlorella AU - Haque, Tarek Md. Anamul AU - Brdecka, Michael AU - Salas, Valeria Duran AU - Jang, Ben T2 - The Canadian Journal of Chemical Engineering AB - Abstract Hydrothermal liquefaction (HTL) is the direct conversion of wet biomass into bio‐oil at high temperature (200–400°C) and high pressure (10–25 MPa). In this work, we investigated HTL with 4.5 g of Chlorella and 45 ml of water/ethanol (1:1 vol. ratio) in a 100 ml reactor. Bio‐oils produced are characterized via elemental analysis, thermogravimetric analysis, and gas chromatography–mass spectrometry (GC–MS). HTL of Chlorella was investigated at 240 and 250°C for 0 and 15 min under an air or H 2 atmosphere and with and without 5% zeolite Y. Temperature increased the bio‐oil yield from 38.75% at 240°C to 43.04% at 250°C for 15 min reaction time. Longer reaction time increased the bio‐oil yield at 250°C from 39.14% for 0 min to 43.04% for 15 min. The H 2 atmosphere had a significant effect for HTL at 240°C. Zeolite Y increased the bio‐oil yield significantly from 32.03% to 43.06% at 250°C for 0 min. The carbon content of bio‐oil increased with the temperature while the oxygen content decreased. The boiling point distribution of bio‐oils in the range of 110–300°C varies with temperature, and atmosphere. At 240°C for 15 min, the 110–300°C range increased from 31.19% in air (240‐15‐air) to 39.25% in H 2 (240‐15‐H 2 ). The H 2 atmosphere increased the content of hydrocarbons, alcohols, and esters from 69.61% in air (240‐0‐air) to 82.83% in H 2 (240‐0‐H 2 ). Overall, temperature, reaction time, atmosphere, and catalyst all significantly influenced the yield and/or quality of bio‐oils from HTL of Chlorella. DA - 2023/10// PY - 2023/10// DO - 10.1002/cjce.24839 UR - https://doi.org/10.1002/cjce.24839 ER - TY - JOUR TI - Optical Nanosensors for the Detection of Quaternary Ammonium Compounds AU - Dewey, Hannah AU - Sultana, Nigar AU - Budhathoki-Uprety, Januka T2 - ECS Meeting Abstracts AB - Quaternary ammonium compounds (QACs) are common active ingredients in chemical disinfectants, household cleaners, cosmetics, pesticides, etc. Recently QACs have been detected in human blood and breast milk during the COVID-19 pandemic. Humans can be exposed to QACs through dermal adsorption during application, hand-to-mouth ingestion of disinfectant residues, and inhalation of indoor air upon treatment with disinfectant spray. Exposure to these chemicals can cause respiratory illness such as asthma and chronic obstructive pulmonary disease, increase inflammatory cytokines, decrease mitochondrial function, and disrupt cholesterol biosynthesis. However, the complete biological fate of QACs is currently unknown. Therefore, a real-time continuous monitoring system in complex biological environments is crucial to learn the long-term effects of QACs on human health. Photoluminescent single-walled carbon nanotubes (SWCNTs) are great candidates for developing optical probes to monitor biological systems due to their outstanding photophysical properties in the tissue-transparent near-infrared spectral region, high sensitivity, and high stability. Furthermore, nanotube-based sensors exhibit a great potential for an implantable, real-time, wireless optical detection technology. Herein, we developed a carbon nanotube-based optical sensor for the detection of QACs in complex solution. Our findings from this research could provide a basis for engineering an optical detection technology to gain insight on the long-term effects of QACs to human health. DA - 2023/8/28/ PY - 2023/8/28/ DO - 10.1149/MA2023-0191132mtgabs UR - https://doi.org/10.1149/MA2023-0191132mtgabs ER - TY - JOUR TI - (Second Place Poster Award) Development of Optical Nanosensors for pH Measurements in Model Biofluids AU - Sultana, Nigar AU - Dewey, Hannah AU - Budhathoki-Uprety, Januka T2 - ECS Meeting Abstracts AB - Changes in pH in biofluids such as urine, sweat, and blood can reveal pathophysiological conditions like tumor metastasis, microbial infection, acidosis, cystic fibrosis, wound healing, etc. Thus, monitoring pH could provide insights on those patho-physiological changes. Among others, sweat analysis provides convenient and non-invasive way to track personal health. Sweat pH changes can reveal information about atopic dermatitis, fungus infections, and cystic fibrosis. Thus, sweat pH measurements could aid in accurately identifying certain health issues. Although solution pH can be measured by various methods including electrochemical, colorimetric and fluorescence measurements, optical pH measurements have gained popularity in recent decades due to versatile material choices and new imaging technologies. Semiconducting single-walled carbon nanotubes (SWCNTs) are emerging molecular optical probes and sensors due to their outstanding photophysical properties, which include photo-stable near-infrared (nIR) fluorescence and sensitive molecular recognition. Here, we report that SWCNT-based sensors can reliably detect pH changes in a model biofluid - artificial sweat. The sensor exhibited significant responses within biologically relevant pH ranges within minutes through changes in the nIR fluorescence. The nanotubes' optical response to pH changes provides new opportunities to develop optical pH sensors for healthcare, bioengineering, environmental sciences, and chemistry. DA - 2023/8/28/ PY - 2023/8/28/ DO - 10.1149/MA2023-0191166mtgabs UR - https://doi.org/10.1149/MA2023-0191166mtgabs ER - TY - JOUR TI - (Invited) Nanoscale Probes for Optical Detection of Emerging Contaminants and Biological Indicators AU - Budhathoki-Uprety, Januka AU - Dewey, Hannah AU - Sultana, Nigar T2 - ECS Meeting Abstracts AB - Photoluminescent single-walled carbon nanotubes exhibit outstanding potential in developing molecular probes for optical detection systems. Surface coatings on nanotubes could facilitate effective molecular interactions enabling targeted nanoscale probes, sensors, and imaging agents. This talk will be focused on the development and applications of carbon nanotube-based sensors for optical detection of emerging contaminants and biological indicators including pH, a measure of acidity and alkalinity of a sample. pH changes in tissues and biofluids could indicate patho-physiological conditions such as tumor growth, microbial infection, acidosis, cystic fibrosis, wound healing, etc. Thus, the optical pH sensor could find applications in disease detection, diagnosis, and improve clinical outcome. This talk will also discuss optical detection of chemical disinfectants using carbon nanotubes. COVID-19 pandemics has led into wide uses of various disinfectant chemicals to mitigate virus burden. Recent findings show that certain disinfectants can cross various biological barriers and accumulate within human body. Molecular tools that enable detection of such compounds within native biological environment are useful to understand complete biological fate of such chemicals to mitigate potential impact on health. DA - 2023/8/28/ PY - 2023/8/28/ DO - 10.1149/MA2023-0191130mtgabs UR - https://doi.org/10.1149/MA2023-0191130mtgabs ER - TY - JOUR TI - Identification and characterization of CHO host-cell proteins in monoclonal antibody bioprocessing T2 - Biotechnology and Bioengineering DA - 2023/9/22/ PY - 2023/9/22/ ER - TY - JOUR TI - Porphene and porphite as porphyrin analogs of graphene and graphite AU - Magnera, Thomas F. AU - Dron, Paul I. AU - Bozzone, Jared AU - Jovanovic, Milena AU - Rončević, Igor AU - Tortorici, Edward AU - Bu, Wei AU - Miller, Elisa M. AU - Rogers, Charles T. AU - MICHL, JOSEF T2 - Nature Communications AB - Two-dimensional materials have unusual properties and promise applications in nanoelectronics, spintronics, photonics, (electro)catalysis, separations, and elsewhere. Most are inorganic and their properties are difficult to tune. Here we report the preparation of Zn porphene, a member of the previously only hypothetical organic metalloporphene family. Similar to graphene, these also are fully conjugated two-dimensional polymers, but are composed of fused metalloporphyrin rings. Zn porphene is synthesized on water surface by two-dimensional oxidative polymerization of a Langmuir layer of Zn porphyrin with K2IrCl6, reminiscent of known one-dimensional polymerization of pyrroles. It is transferable to other substrates and bridges μm-sized pits. Contrary to previous theoretical predictions of metallic conductivity, it is a p-type semiconductor due to a predicted Peierls distortion of its unit cell from square to rectangular, analogous to the appearance of bond-length alternation in antiaromatic molecules. The observed reversible insertion of various metal ions, possibly carrying a fifth or sixth ligand, promises tunability and even patterning of circuits on an atomic canvas without removing any π centers from conjugation. DA - 2023/10/9/ PY - 2023/10/9/ DO - 10.1038/s41467-023-41461-w VL - 14 IS - 1 UR - http://dx.doi.org/10.1038/s41467-023-41461-w ER - TY - JOUR TI - Influence of Polyoxovanadate and Phthalocyanine on 4f Electron Transfer in Gold-Confined Monolayers Probed with EGaIn Top Contacts AU - Soni, Saurabh AU - Werner, Irina AU - Aidi, Michael AU - Moors, Marco AU - Mthembu, C. Lungani AU - Zharnikov, Michael AU - Havenith, Remco W. A. AU - Monakhov, Kirill Yu. AU - Chiechi, Ryan C. T2 - ACS APPLIED NANO MATERIALS AB - This work describes the effects of dodecavanadate anions and phthalocyanine ligands as well as the identity of lanthanide centers on the charge transport characteristics of heterometallic complexes (nBu4N)3[HV12O32Cl(LnPc)] and (nBu4N)2[HV12O32Cl(LnPc)2] for SmIII–ErIII, LuIII, and YIII on gold surfaces. In molecular ensemble junctions with eutectic Ga–In top contacts, the complexes containing two phthalocyanine ligands are highly conductive but show no clear effect of varying the lanthanide. By contrast, the complexes that omit phthalocyanine but include 4f-functionalized dodecavanadate building blocks show clear trends in conductance, rectification, and transition voltages. Density functional theory calculations show that the occupied and unoccupied frontier orbitals in the heterometallic complexes are delocalized on the phthalocyanine ligand and dodecavanadate anion, respectively, suggesting strong lanthanide–ligand electronic coupling. Near-edge X-ray absorption fine structure spectroscopy on these complexes further suggests that the phthalocyanine ligands are arranged such that their edges are in contact with the electrodes, creating tunneling transmission channels that bypass the lanthanide, effectively obviating the electronic contributions of the lanthanide centers to charge transport. These results separate the influence of the individual constituents of these metal–ligand complexes on the tunneling charge-transport properties. These results demonstrate how strongly coupled ligands such as phthalocyanine can dominate charge transport, from which we construct design rules for harnessing the properties of f-block elements in redox-active molecular heterojunctions. DA - 2023/12/7/ PY - 2023/12/7/ DO - 10.1021/acsanm.3c05021 VL - 6 IS - 24 SP - 22643-22650 SN - 2574-0970 UR - https://doi.org/10.1021/acsanm.3c05021 KW - EGaIn KW - Polyoxometalate KW - Molecularelectronics KW - Vanadium KW - Lanthanide KW - Scanningprobe methods ER - TY - JOUR TI - Observation of Weak Counterion Size Dependence of Thermoelectric Transport in Ion Exchange Doped Conducting Polymers Across a Wide Range of Conductivities AU - Chen, Chen AU - Jacobs, Ian E. AU - Kang, Keehoon AU - Lin, Yue AU - Jellett, Cameron AU - Kang, Boseok AU - Lee, Seon Baek AU - Huang, Yuxuan AU - BaloochQarai, Mohammad AU - Ghosh, Raja AU - Statz, Martin AU - Wood, William AU - Ren, Xinglong AU - Tjhe, Dion AU - Sun, Yuanhui AU - She, Xiaojian AU - Hu, Yuanyuan AU - Jiang, Lang AU - Spano, Frank C. AU - McCulloch, Iain AU - Sirringhaus, Henning T2 - Advanced Energy Materials AB - Abstract Conducting polymers are of interest for a broad range of applications from bioelectronics to thermoelectrics. The factors that govern their complex charge transport physics include the structural disorder present in these highly doped polymer films and the Coulombic interactions between the electronic charge carriers and the dopant counterions. Previous studies have shown that at low doping levels carriers are strongly trapped in the vicinity of the counterions, while at high doping levels charge transport is not limited by Coulombic trapping, which manifests itself in the conductivity being independent of the size of the dopant counterion. Here a recently developed ion exchange doping method is used to investigate the ion size dependence of a semicrystalline polythiophene‐based model system across a wide range of conductivities. It is found that the regime in which the charge and thermoelectric transport is not or only weakly dependent on ion size, extends to surprisingly low conductivities. This surprising observation is explained by a heterogeneous doping that involves doping of the amorphous domains to high doping levels first before doping of the ordered, crystalline domains occurs. The study provides new insights into how the thermoelectric physics of conducting polymers evolves as a function of doping level. DA - 2023/1/10/ PY - 2023/1/10/ DO - 10.1002/aenm.202202797 VL - 13 IS - 9 J2 - Advanced Energy Materials LA - en OP - SN - 1614-6832 1614-6840 UR - http://dx.doi.org/10.1002/aenm.202202797 DB - Crossref ER - TY - JOUR TI - Engineering Flat and Dispersive Bands in 2D Layered COFs via Interlayer Stacking and Donor–Acceptor Strategy AU - Pan, Yuanhui AU - Ho, Ching-Hwa AU - Paesani, Francesco AU - Ghosh, Raja T2 - Chemistry of Materials AB - Covalent organic frameworks (COFs) are an emergent class of two-dimensional (2D) crystalline organic materials that exhibit unique electronic, optical, and transport properties. In this study, we employ density functional theory (DFT) and the Multiparticle Holstein Formalism (MHF) to investigate the electronic structure and the two-dimensional coherence of polarons in donor–acceptor COFs as a function of the interlayer stacking arrangement. We show that simple modifications in the interlayer stacking arrangement have a profound impact on the transport properties, which can range from metallic behavior with a vanishing band gap to highly localized states having flat bands. The extent of charge delocalization is found to be sensitive to the type of stacking arrangement and to the precise arrangement of the donor and acceptor fragments within the COF structure. The results from the DFT calculations are consistent with MHF-based simulations, demonstrating that stacking-induced interlayer interactions may facilitate better intraframework charge delocalization. As a consequence, we find that interlayer interactions can help circumvent defect-induced trap states to enhance the overall charge delocalization. Based on these analyses, we conclude that interlayer stacking can be exploited to guide the design of new 2D layered COF structures, with potential applications in organic electronics. DA - 2023/8/1/ PY - 2023/8/1/ DO - 10.1021/acs.chemmater.3c00510 VL - 35 IS - 16 SP - 6235-6245 J2 - Chem. Mater. LA - en OP - SN - 0897-4756 1520-5002 UR - http://dx.doi.org/10.1021/acs.chemmater.3c00510 DB - Crossref ER - TY - JOUR TI - Multipolaron Complexes in Conducting Polymers: The Importance of Hole–Hole Repulsion in Charge Delocalization AU - Balooch Qarai, Mohammad AU - Ghosh, Raja AU - Hestand, Nicholas J. AU - Spano, Frank C. T2 - The Journal of Physical Chemistry C AB - Multipolaron complexes in p-doped poly(3-hexylthiophene) films are investigated theoretically for polaron-anion configurations in which stationary dopant anions are positioned on both sides of the polymer chain, within the lamellar region. Complexes as large as tetrapolarons, consisting of four anions and an equal number of mobile holes, are considered. It is found that the mid-IR absorption band (P1) red-shifts and the hole ionization potential decreases as the complex grows in size, from a single polaron to a tetrapolaron. Such behavior is shown to arise mainly from enhanced hole delocalization due to hole–hole repulsion and has important implications for charge transport in organic materials. DA - 2023/3/23/ PY - 2023/3/23/ DO - 10.1021/acs.jpcc.3c00289 VL - 127 IS - 13 SP - 6414-6424 J2 - J. Phys. Chem. C LA - en OP - SN - 1932-7447 1932-7455 UR - http://dx.doi.org/10.1021/acs.jpcc.3c00289 DB - Crossref ER - TY - JOUR TI - Connecting the dots for fundamental understanding of structure–photophysics–property relationships of COFs, MOFs, and perovskites using a Multiparticle Holstein Formalism AU - Ghosh, Raja AU - Paesani, Francesco T2 - Chemical Science AB - The Multiparticle Holstein Formalism is a promising theoretical framework that efficiently bridges the gap between theory and experiments. DA - 2023/// PY - 2023/// DO - 10.1039/D2SC03793A VL - 14 IS - 5 SP - 1040-1064 J2 - Chem. Sci. LA - en OP - SN - 2041-6520 2041-6539 UR - http://dx.doi.org/10.1039/d2sc03793a DB - Crossref ER - TY - JOUR TI - Photoredox Catalyzed C(sp3)-C(sp3) Coupling of α-Bromoesters and Triethylamine AU - Guerra, Allie W. AU - Pierce, Joshua G. T2 - JOURNAL OF ORGANIC CHEMISTRY AB - We report a photoredox methodology for C(sp3)–C(sp3) coupling between α-bromoesters and triethylamine capable of accessing building blocks with handles for further functionalization. Mechanistic studies indicate the presence of a carbon centered radical. The achiral substrates obtained with this method have the potential to be elaborated to access enantioenriched scaffolds with increased molecular complexity. DA - 2023/12/21/ PY - 2023/12/21/ DO - 10.1021/acs.joc.3c02394 VL - 89 IS - 1 SP - 810-814 SN - 1520-6904 ER - TY - JOUR TI - Achieving Cross-Ring Fragmentation of N-Linked Glycans by IR-MALDESI AU - Palomino, Tana V. AU - Muddiman, David C. T2 - JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY AB - Glycans are complex structures that require MS/MS for detailed structural elucidation. Incorporating metals can provide more structural information by inhibiting glycosidic cleavage and enhancing cross-ring fragmentation. A direct analysis was performed using lithium doping and IR-MALDESI to induce cross-ring fragmentation of glycans. The protonated and lithiated versions of the two glycans were isolated and subjected to HCD. For protonated glycans, only glycosidic cleavages were observed. Using lithium doping, MS/MS consisted of abundant cross-ring fragments. Seventeen cross-ring fragments were detected across both glycans using lithium-doped ESI. This is the first incorporation of metal doping in IR-MALDESI to achieve cross-ring fragments in MS/MS analysis. DA - 2023/12/19/ PY - 2023/12/19/ DO - 10.1021/jasms.3c00283 VL - 35 IS - 1 SP - 166-171 SN - 1879-1123 KW - N-linked glycans KW - lithium doping KW - fragmentation KW - IR-MALDESI KW - cross-ring fragment ER - TY - JOUR TI - Exploring Electrochemistry: A Hydrogen Peroxide Sensor Based on a Screen-Printed Carbon Electrode Modified with Prussian Blue AU - Todorov, Jovica AU - McCarty, Gregory S. AU - Sombers, Leslie A. T2 - JOURNAL OF CHEMICAL EDUCATION AB - There is an increasing need for fundamental electrochemistry concepts to be taught in the undergraduate curriculum, given the broad applicability of electrochemical technologies in addressing a wide range of global issues from critical energy shortages to real-time medical diagnostics. However, many electrochemical concepts are often taught in disparate laboratory experiments, spread out through the curriculum, which can be intimidating to students (and instructors). This experiment, which has been tested and optimized in the undergraduate classroom over multiple semesters, covers a wide range of electrochemistry topics in realizing the construction of a hydrogen peroxide (H2O2) sensor that is based on Prussian blue electrochemistry. The experiment introduces the fundamentals of cyclic voltammetry by prompting students to distinguish faradaic and capacitive components of voltammograms and to investigate their relationship with scan rate as per electrochemical theory. Students also evaluate electrocatalysis through electrodeposition of a thin film of Prussian blue on the sensor surface and the effects of this modification on electron transfer and sensor performance. Finally, students combine amperometric measurements with the method of standard additions to determine H2O2 concentrations in an unknown sample. Overall, this experiment offers an integrated and cohesive experience that connects many important electroanalytical concepts that are often taught individually into one 3 h, hands-on laboratory experiment that requires minimal resources. DA - 2023/11/7/ PY - 2023/11/7/ DO - 10.1021/acs.jchemed.3c00844 VL - 100 IS - 12 SP - 4853-4859 SN - 1938-1328 KW - Upper-Division Undergraduate KW - AnalyticalChemistry KW - Laboratory Equipment KW - Hands-On Learning KW - Electrochemistry KW - Quantitative Analysis ER - TY - JOUR TI - Optical bandgap anomaly with tuning dimensionality in germanium perovskites: Interplay between quantum confinement and lone pair expression AU - Li, Xinyu AU - Tao, Yu AU - Jiang, Xiaofan AU - Cai, Guanqun AU - Gu, Jiazhen AU - Zheng, Nanlong AU - Guan, Yan AU - Zhang, Wenkai AU - Li, Xiaotong AU - Su, Jie AU - Liu, Zhiwei AU - Bian, Zuqiang AU - Sun, Junliang AU - Li, Chen AU - Fu, Yongping T2 - Chem AB - The optical bandgaps of 2D halide perovskites (HPs) generally decrease with increasing inorganic layer thickness because of the diminishing quantum confinement (QC) effect. Here, we report a reverse bandgap trend in a class of Ge-based HPs, achieved through a judicious selection of organic cations, which exhibits an enhanced stereochemical lone pair expression (LPE) on the Ge2+ cation with increasing inorganic layer thickness. We find the enhanced LPE arises from cooperative interlayer compression and intralayer expansion on the inorganic lattice induced by a small spacer cation and a large cage A-cation, respectively. Experimental and theoretical studies show that such enhanced LPE can shift up the bandgap, which is significant enough to offset the QC effect, leading to the bandgap anomaly with tuning dimensionality. Our results reveal a previously underexplored avenue to tune the optical and electronic properties of 2D HPs by rationally controlling the LPE through interlayer and intralayer engineering. DA - 2023/12// PY - 2023/12// DO - 10.1016/j.chempr.2023.11.011 VL - 12 J2 - Chem LA - en OP - SN - 2451-9294 UR - http://dx.doi.org/10.1016/j.chempr.2023.11.011 DB - Crossref ER - TY - JOUR TI - Lattice engineering for stabilized black FAPbI 3 perovskite single crystals for high-resolution x-ray imaging at the lowest dose AU - Chu, Depeng AU - Jia, Binxia AU - Liu, Naiming AU - Zhang, Yunxia AU - Li, Xiaotong AU - Feng, Jiangshan AU - Pi, Jiacheng AU - Yang, Zhou AU - Zhao, Guangtao AU - Liu, Yucheng AU - Liu, Shengzhong (Frank) AU - Park, Nam-Gyu T2 - Science Advances AB - Preliminary theoretical analyses indicate that lattice relaxation may be used to release lattice strain in the FAPbI 3 perovskite to warrant both high x-ray detection performance and improved stability. Herein, we demonstrate stable black α-phase FAPbI 3 single crystals (SCs) realized by lattice engineering via annealing in the ambient atmosphere. The engineered α-FAPbI 3 SC detector shows almost all the best figures of merit including a high sensitivity of 4.15 × 10 5 μC Gy air −1 cm −2 , a low detection limit of 1.1 nGy air s −1 , a high resolution of 15.9 lp mm −1 , and a short response time of 214 μs. We further demonstrate high-definition x-ray imaging at a dose rate below 10 nGy air s −1 on the FAPbI 3 SC, indicating a minimal dose-area product of 0.048 mGy air cm 2 to the patient for one-time posteroanterior chest diagnosis, which is more than 3000 times lower than the international reference level of 150 mGy air cm 2 . In addition, the robust long-term stability enables the FAPbI 3 SC x-ray detector to work steadily for more than 40 years. DA - 2023/9// PY - 2023/9// DO - 10.1126/sciadv.adh2255 VL - 9 IS - 35 J2 - Sci. Adv. LA - en OP - SN - 2375-2548 UR - http://dx.doi.org/10.1126/sciadv.adh2255 DB - Crossref ER - TY - JOUR TI - Correlating Photophysical Properties with Stereochemical Expression of 6s2 Lone Pairs in Two‐dimensional Lead Halide Perovskites AU - Gu, Jiazhen AU - Tao, Yu AU - Fu, Tonghuan AU - Guo, Songhao AU - Jiang, Xiaofan AU - Guan, Yan AU - Li, Xiaotong AU - Li, Chen AU - Lü, Xujie AU - Fu, Yongping T2 - Angewandte Chemie International Edition AB - Abstract Two‐dimensional (2D) lead halide perovskites (LHPs) have shown great promises for light‐emitting applications and excitonic devices. Fulfilling these promises demands an in‐depth understanding on the relationships between the structural dynamics and exciton‐phonon interactions that govern the optical properties. Here, we unveil the structural dynamics of 2D lead iodide perovskites with different spacer cations. Loose packing of an undersized spacer cation leads to out‐of‐plane octahedral tilting, whereas compact packing of an oversized spacer cation stretches Pb−I bond length, resulting in Pb 2+ off‐center displacement driven by stereochemical expression of the Pb 2+ 6s 2 lone pair electrons. Density functional theory calculations indicate that the Pb 2+ cation is off‐center displaced mainly along the direction where the octahedra are stretched the most by the spacer cation. We find dynamic structural distortions associated with either octahedral tilting or Pb 2+ off‐centering lead to a broad Raman central peak background and phonon softening, which increase the non‐radiative recombination loss via exciton‐phonon interactions and quench the photoluminescence intensity. The correlations between the structural, phonon, and optical properties are further confirmed by the pressure tuning of the 2D LHPs. Our results demonstrate that minimizing the dynamic structural distortions via a judicious selection of the spacer cations is essential to realize high luminescence properties in 2D LHPs. DA - 2023/6/20/ PY - 2023/6/20/ DO - 10.1002/anie.202304515 VL - 62 IS - 30 J2 - Angew Chem Int Ed LA - en OP - SN - 1433-7851 1521-3773 UR - http://dx.doi.org/10.1002/anie.202304515 DB - Crossref ER - TY - JOUR TI - Allosteric site variants affect GTP hydrolysis on Ras AU - Johnson, Christian W. AU - Fetics, Susan K. AU - Davis, Kathleen P. AU - Rodrigues, Jose A. AU - Mattos, Carla T2 - PROTEIN SCIENCE AB - Abstract RAS GTPases are proto‐oncoproteins that regulate cell growth, proliferation, and differentiation in response to extracellular signals. The signaling functions of RAS, and other small GTPases, are dependent on their ability to cycle between GDP‐bound and GTP‐bound states. Structural analyses suggest that GTP hydrolysis catalyzed by HRAS can be regulated by an allosteric site located between helices 3, 4, and loop 7. Here we explore the relationship between intrinsic GTP hydrolysis on HRAS and the position of helix 3 and loop 7 through manipulation of the allosteric site, showing that the two sites are functionally connected. We generated several hydrophobic mutations in the allosteric site of HRAS to promote shifts in helix 3 relative to helix 4. By combining crystallography and enzymology to study these mutants, we show that closure of the allosteric site correlates with increased hydrolysis of GTP on HRAS in solution. Interestingly, binding to the RAS binding domain of RAF kinase (RAF‐RBD) inhibits GTP hydrolysis in the mutants. This behavior may be representative of a cluster of mutations found in human tumors, which potentially cooperate with RAF complex formation to stabilize the GTP‐bound state of RAS. DA - 2023/10// PY - 2023/10// DO - 10.1002/pro.4767 VL - 32 IS - 10 SP - SN - 1469-896X KW - allosteric site KW - allostery KW - HRAS KW - hydrolysis KW - KRAS KW - mutation KW - RAF KW - small GTPase ER - TY - JOUR TI - Small-Molecule CO2 Donors Accelerate Three-Component Peptide/Protein Bioconjugation with Alkylazides and Phosphines in Ionic Liquids AU - Colella, Brandon M. AU - Ohata, Jun T2 - SYNLETT AB - Abstract Development of chemical modification techniques for peptides and proteins has been facilitated by a set of multicomponent reactions to date. This Letter demonstrates the use of small-molecule CO2 donors to promote reaction efficiency of the coupling of alkylamine on peptides and proteins with azide-derived iminophosphorane and carbon dioxide. DA - 2023/12/18/ PY - 2023/12/18/ DO - 10.1055/a-2212-7816 VL - 12 SP - SN - 1437-2096 UR - https://doi.org/10.1055/a-2212-7816 KW - multicomponent reaction KW - CO2 donor KW - peptide KW - protein KW - amine KW - azide KW - phosphine ER - TY - JOUR TI - Evaluation of Endoplasmic Reticulum Targeting Isoquinol-Based BODIPY Dyes and Their Properties as Molecular Rotors AU - Swavey, Shawn AU - Heidary, David AU - Boyd, Emma AU - Erb, Jeremy T2 - EUROPEAN JOURNAL OF ORGANIC CHEMISTRY AB - Abstract A series of six new isoquinol‐based BODIPY dyes have been synthesized by a two‐step method. Unlike traditional synthetic methods, synthesis did not require the use of oxidizing agents or solvent. Spectroscopic, electrochemical and DFT calculations indicate that the properties associated with the six dyes are very similar with little influence of the meso ‐substituents. Viscosity studies identified three of the new dyes having properties of molecular rotors for applications in the detection of changes in cellular viscosity. Incubation of the dyes with the HEK cell line show no toxicity up to 10 μM over a 72 h. period. The dyes show the ability to localize within the endoplasmic reticulum (ER) of cells. With two of the dyes showing favorable comparisons to commercially available ER dyes. DA - 2023/11/21/ PY - 2023/11/21/ DO - 10.1002/ejoc.202300777 SP - SN - 1099-0690 KW - BODIPY KW - cellular probes KW - endoplasmic reticulum KW - viscosity ER - TY - JOUR TI - Simultaneous, Real-Time Detection of Glutamate and Dopamine in Rat Striatum Using Fast-Scan Cyclic Voltammetry AU - Kimble, Laney C. AU - Twiddy, Jack S. AU - Berger, Jenna M. AU - Forderhase, Alexandra G. AU - Mccarty, Gregory S. AU - Meitzen, John AU - Sombers, Leslie A. T2 - ACS SENSORS AB - Glutamate and dopamine (DA) represent two key contributors to striatal functioning, a region of the brain that is essential to motor coordination and motivated behavior. While electroanalytical techniques can be utilized for rapid, spatially resolved detection of DA in the interferent-rich brain environment, glutamate, a nonelectroactive analyte, cannot be directly detected using electroanalytical techniques. However, it can be probed using enzyme-based sensors, which generate an electroactive reporter in the presence of glutamate. The vast majority of glutamate biosensors have relied on amperometric sensing, which is an inherently nonselective detection technique. This approach necessitates the use of complex and performance-limiting modifications to ensure the desired single-analyte specificity. Here, we present a novel glutamate microbiosensor fabricated on a carbon-fiber microelectrode substrate and coupled with fast-scan cyclic voltammetry (FSCV) to enable the simultaneous quantification of glutamate and DA at single recording sites in the brain, which is impossible when using typical amperometric approaches. The glutamate microbiosensors were characterized for sensitivity, stability, and selectivity by using a voltammetric waveform optimized for the simultaneous detection of both species. The applicability of these sensors for the investigation of neural circuits was validated in the rat ventral striatum. Electrically evoked glutamate and DA release were recorded at single-micrometer-scale locations before and after pharmacological manipulation of glutamatergic signaling. Our novel glutamate microbiosensor advances the state of the art by providing a powerful tool for probing coordination between these two species in a way that has previously not been possible. DA - 2023/11/14/ PY - 2023/11/14/ DO - 10.1021/acssensors.3c01267 VL - 8 IS - 11 SP - 4091-4100 SN - 2379-3694 KW - FSCV KW - biosensor KW - carbon-fiber microelectrode KW - excitatory amino acid transporter KW - dl-threo-beta-benzyloxyaspartic acid KW - dl-TBOA ER - TY - JOUR TI - A combination of organic and inorganic cations in the synthesis of transition metal nitrates: preparation and characterization of canted rectangular Ising antiferromagnet (PyH)CsCo2(NO3)6 AU - Vorobyova, A. A. AU - Lyssenko, K. A. AU - Chistyakov, G. D. AU - Morozov, I. V. AU - Ovchenkov, Y. A. AU - Vasilchikova, T. M. AU - Koo, H. -J. AU - Whangbo, M. -H. AU - Volkova, O. S. AU - Vasiliev, A. N. T2 - DALTON TRANSACTIONS AB - Pyridinium cesium cobalt nitrate, (PyH)CsCo2(NO3)6, obtained from a nitric acid solution crystallizes in the orthorhombic space group Pnma with unit cell parameters a = 8.6905(14) Å, b = 11.9599(18) Å, c = 18.386(3) Å, V = 1911.0(5) Å3, and Z = 4. It consists of [Co(NO3)3]- layers, in which each Co2+ ion is connected with four monodentate bridging NO3-groups and one bidentate terminal NO3-group, forming a corrugated rectangular net. Magnetization and specific heat measurements show that (PyH)CsCo2(NO3)6 undergoes a long-range canted antiferromagnetic ordering in two steps at TC1 = 5.0 K and TC2 = 2.6 K. The temperature dependence of the magnetic susceptibility and the field dependence of the magnetization measured for (PyH)CsCo2(NO3)6 show that it is an Ising antiferromagnet. In support of these observations, our DFT + U + SOC calculations show that the Co2+ ions of (PyH)CsCo2(NO3)6 have an easy-axis magnetic anisotropy with preferred spin orientation along the b-axis. To a first approximation, the spin lattice of (PyH)CsCo2(NO3)6 is a weakly alternating Ising antiferromagnetic chain (J1/J2 ∼ 0.85), and these chains interact weakly (J3/J2 ∼ 0.07) to form a rectangular Ising antiferromagnetic lattice. In agreement with the prediction for a rectangular Ising antiferromagnet by Onsager, (PyH)CsCo2(NO3)6 undergoes a long-range antiferromagnetic ordering. DA - 2023/11/9/ PY - 2023/11/9/ DO - 10.1039/d3dt03159d SP - SN - 1477-9234 ER - TY - JOUR TI - Characterizing Adeno-Associated Virus Capsids with Both Denaturing and Intact Analysis Methods AU - Ryan, Jack P. AU - Kostelic, Marius M. AU - Hsieh, Chih-Chieh AU - Powers, Joshua AU - Aspinwall, Craig AU - Dodds, James N. AU - Schiel, John E. AU - Marty, Michael T. AU - Baker, Erin S. T2 - JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY AB - Adeno-associated virus (AAV) capsids are among the leading gene delivery platforms used to treat a vast array of human diseases and conditions. AAVs exist in a variety of serotypes due to differences in viral protein (VP) sequences with distinct serotypes targeting specific cells and tissues. As the utility of AAVs in gene therapy increases, ensuring their specific composition is imperative for the correct targeting and gene delivery. From a quality control perspective, current analytical tools are limited in their selectivity for viral protein (VP) subunits due to their sequence similarities, instrumental difficulties in assessing the large molecular weights of intact capsids, and the uncertainty in distinguishing empty and filled capsids. To address these challenges, we combined two distinct analytical workflows that assess the intact capsids and VP subunits separately. First, a selective temporal overview of resonant ion (STORI)-based charge detection-mass spectrometry (CD-MS) was applied for characterization of the intact capsids. Liquid chromatography, ion mobility spectrometry, and mass spectrometry (LC-IMS-MS) separations were then used for the capsid denaturing measurements. This multimethod combination was applied to three AAV serotypes (AAV2, AAV6, and AAV8) to evaluate their intact empty and filled capsid ratios and then examine the distinct VP sequences and modifications present. DA - 2023/11/27/ PY - 2023/11/27/ DO - 10.1021/jasms.3c00321 VL - 34 IS - 12 SP - 2811-2821 SN - 1879-1123 ER - TY - JOUR TI - The role of sound stimulation in production of plant secondary metabolites AU - Wu, Li AU - Yang, Ning AU - Guo, Meng AU - Zhang, Didi AU - Ghiladi, Reza A. AU - Bayram, Hasan AU - Wang, Jun T2 - NATURAL PRODUCTS AND BIOPROSPECTING AB - Abstract Sound vibration is one of natural stimuli trigging physiological changes in plants. Recent studies showed that sound waves stimulated production of a variety of plant secondary metabolites, including flavonoids, in order to enhance seed germination, flowering, growth or defense. In this review, we examine the potential role of sound stimulation on the biosynthesis of secondary metabolites and the followed cascade of physiological changes in plants, from the perspective of transcriptional regulation and epigenetic regulation for the first time. A systematic summary showed that a wide range of factors may regulate the production of secondary metabolites, including plant species, growth stage, sound types, sound frequency, sound intensity level and exposure time, etc. Biochemical and physiological changes due to sound stimulation were thoroughly summarized as well, for secondary metabolites can also act as a free radical scavenger, or a hormone signaling molecule. We also discussed the limits of previous studies, and the future application of sound waves in biosynthesis of plant secondary metabolites. DA - 2023/12// PY - 2023/12// DO - 10.1007/s13659-023-00409-9 VL - 13 IS - 1 SP - SN - 2192-2209 KW - Sound KW - Music KW - Plant secondary metabolites KW - Flavonoid KW - Antioxidant KW - Immunity ER - TY - JOUR TI - Mechanistic Analysis of Stereodivergent Nitroalkane Cyclopropanation Catalyzed by Nonheme Iron Enzymes AU - Ushimaru, Richiro AU - Cha, Lide AU - Shimo, Shotaro AU - Li, Xiaojun AU - Paris, Jared C. AU - Mori, Takahiro AU - Miyamoto, Kazunori AU - Coffer, Lindsay AU - Uchiyama, Masanobu AU - Guo, Yisong AU - Chang, Wei-chen AU - Abe, Ikuro T2 - JOURNAL OF THE AMERICAN CHEMICAL SOCIETY AB - BelL and HrmJ are α-ketoglutarate-dependent nonheme iron enzymes that catalyze the oxidative cyclization of 6-nitronorleucine, resulting in the formation of two diastereomeric 3-(2-nitrocyclopropyl)alanine (Ncpa) products containing trans-cyclopropane rings with (1'R,2'R) and (1'S,2'S) configurations, respectively. Herein, we investigate the catalytic mechanism and stereodivergency of the cyclopropanases. The results suggest that the nitroalkane moiety of the substrate is first deprotonated to produce the nitronate form. Spectroscopic analyses and biochemical assays with substrates and analogues indicate that an iron(IV)-oxo species abstracts proS-H from C4 to initiate intramolecular C-C bond formation. A hydroxylation intermediate is unlikely to be involved in the cyclopropanation reaction. Additionally, a genome mining approach is employed to discover new homologues that perform the cyclopropanation of 6-nitronorleucine to generate cis-configured Ncpa products with (1'R,2'S) or (1'S,2'R) stereochemistries. Sequence and structure comparisons of these cyclopropanases enable us to determine the amino acid residues critical for controlling the stereoselectivity of cyclopropanation. DA - 2023/10/24/ PY - 2023/10/24/ DO - 10.1021/jacs.3c08413 VL - 145 IS - 44 SP - 24210-24217 SN - 1520-5126 ER - TY - JOUR TI - Untapped Potential: Real-Time Measurements of Opioid Exocytosis at Single Cells AU - Denison, J. Dylan AU - De Alwis, A. Chathuri AU - Shah, Ruby AU - Mccarty, Gregory S. AU - Sombers, Leslie A. T2 - JOURNAL OF THE AMERICAN CHEMICAL SOCIETY AB - The endogenous opioid system is commonly targeted in pain treatment, but the fundamental nature of neuropeptide release remains poorly understood due to a lack of methods for direct detection of specific opioid neuropeptides in situ. These peptides are concentrated in, and released from, large dense-core vesicles in chromaffin cells. Although catecholamine release from these neuroendocrine cells is well characterized, the direct quantification of opioid peptide exocytosis events has not previously been achieved. In this work, a planar carbon-fiber microelectrode served as a "postsynaptic" sensor for probing catecholamine and neuropeptide release dynamics via amperometric monitoring. A constant potential of 500 mV was employed for quantification of catecholamine release, and a higher potential of 1000 mV was used to drive oxidation of tyrosine, the N-terminal amino acid in the opioid neuropeptides released from chromaffin cells. By discriminating the results collected at the two potentials, the data reveal unique kinetics for these two neurochemical classes at the single-vesicle level. The amplitude of the peptidergic signals decreased with repeat stimulation, as the halfwidth of these signals simultaneously increased. By contrast, the amplitude of catecholamine release events increased with repeat stimulation, but the halfwidth of each event did not vary. The chromogranin dense core was identified as an important mechanistic handle by which separate classes of transmitter can be kinetically modulated when released from the same population of vesicles. Overall, the data provide unprecedented insight into key differences between catecholamine and opioid neuropeptide release from isolated chromaffin cells. DA - 2023/10/19/ PY - 2023/10/19/ DO - 10.1021/jacs.3c07487 VL - 145 IS - 44 SP - 24071-24080 SN - 1520-5126 ER - TY - JOUR TI - Dissection of MKK6 and p38 Signaling Using Light-Activated Protein Kinases AU - Rahman, Shah Md. Toufiqur AU - Zhou, Wenyuan AU - Deiters, Alexander AU - Haugh, Jason M. T2 - CHEMBIOCHEM AB - Abstract Stress‐activated signaling pathways orchestrate cellular behaviors and fates. Studying the precise role(s) of stress‐activated protein kinases is challenging, because stress conditions induce adaptation and impose selection pressure. To meet this challenge, we have applied an optogenetic system with a single plasmid to express light‐activated p38α or its upstream activator, MKK6, in conjunction with live‐cell fluorescence microscopy. In starved cells, decaging of constitutively active p38α or MKK6 by brief exposure to UV light elicits rapid p38‐mediated signaling, release of cytochrome c from mitochondria, and apoptosis with different kinetics. In parallel, light activation of p38α also suppresses autophagosome formation, similarly to stimulation with growth factors that activate PI3K/Akt/mTORC1 signaling. Active MKK6 negatively regulates serum‐induced ERK activity, which is p38‐independent as previously reported. Here, we reproduce that result with the one plasmid system and show that although decaging active p38α does not reduce basal ERK activity in our cells, it can block growth factor‐stimulated ERK signaling in serum‐starved cells. These results clarify the roles of MKK6 and p38α in dynamic signaling programs, which act in concert to actuate apoptotic death while suppressing cell survival mechanisms. DA - 2023/11/7/ PY - 2023/11/7/ DO - 10.1002/cbic.202300551 SP - SN - 1439-7633 KW - apoptosis KW - autophagy KW - cell death KW - growth factors KW - mitogen-activated protein kinases KW - optogenetics KW - signal transduction ER - TY - JOUR TI - Public Communication as a Mechanism for Collusion in the Broiler Industry AU - Sheng, Qiwen AU - Vukina, Tomislav T2 - REVIEW OF INDUSTRIAL ORGANIZATION DA - 2023/11/11/ PY - 2023/11/11/ DO - 10.1007/s11151-023-09929-7 SP - SN - 1573-7160 KW - Text as data KW - Natural language processing KW - Coordinated capacity reduction ER - TY - JOUR TI - Observation of parallel intersystem crossing and charge transfer-state dynamics in [Fe(bpy)3]2+ from ultrafast 2D electronic spectroscopy AU - Lee, Angela AU - Son, Minjung AU - Deegbey, Mawuli AU - Woodhouse, Matthew D. AU - Hart, Stephanie M. AU - Beissel, Hayden F. AU - Cesana, Paul T. AU - Jakubikova, Elena AU - McCusker, James K. AU - Schlau-Cohen, Gabriela S. T2 - CHEMICAL SCIENCE AB - Transition metal-based charge-transfer complexes represent a broad class of inorganic compounds with diverse photochemical applications. Charge-transfer complexes based on earth-abundant elements have been of increasing interest, particularly the canonical [Fe(bpy)3]2+. Photoexcitation into the singlet metal-ligand charge transfer (1MLCT) state is followed by relaxation first to the ligand-field manifold and then to the ground state. While these dynamics have been well-studied, processes within the MLCT manifold that facilitate and/or compete with relaxation have been more elusive. We applied ultrafast two-dimensional electronic spectroscopy (2DES) to disentangle the dynamics immediately following MLCT excitation of this compound. First, dynamics ascribed to relaxation out of the initially formed 1MLCT state was found to correlate with the inertial response time of the solvent. Second, the additional dimension of the 2D spectra revealed a peak consistent with a ∼20 fs 1MLCT → 3MLCT intersystem crossing process. These two observations indicate that the complex simultaneously undergoes intersystem crossing and direct conversion to ligand-field state(s). Resolution of these parallel pathways in this prototypical earth-abundant complex highlights the ability of 2DES to deconvolve the otherwise obscured excited-state dynamics of charge-transfer complexes. DA - 2023/11/22/ PY - 2023/11/22/ DO - 10.1039/d3sc02613b VL - 14 IS - 45 SP - 13140-13150 SN - 2041-6539 ER - TY - JOUR TI - Smart Dope: A Self-Driving Fluidic Lab for Accelerated Development of Doped Perovskite Quantum Dots AU - Bateni, Fazel AU - Sadeghi, Sina AU - Orouji, Negin AU - Bennett, Jeffrey A. AU - Punati, Venkat S. AU - Stark, Christine AU - Wang, Junyu AU - Rosko, Michael C. AU - Chen, Ou AU - Castellano, Felix N. AU - Reyes, Kristofer G. AU - Abolhasani, Milad T2 - ADVANCED ENERGY MATERIALS AB - Abstract Metal cation‐doped lead halide perovskite (LHP) quantum dots (QDs) with photoluminescence quantum yields (PLQYs) higher than unity, due to quantum cutting phenomena, are an important building block of the next‐generation renewable energy technologies. However, synthetic route exploration and development of the highest‐performing QDs for device applications remain challenging. In this work, Smart Dope is presented, which is a self‐driving fluidic lab (SDFL), for the accelerated synthesis space exploration and autonomous optimization of LHP QDs. Specifically, the multi‐cation doping of CsPbCl 3 QDs using a one‐pot high‐temperature synthesis chemistry is reported. Smart Dope continuously synthesizes multi‐cation‐doped CsPbCl 3 QDs using a high‐pressure gas‐liquid segmented flow format to enable continuous experimentation with minimal experimental noise at reaction temperatures up to 255°C. Smart Dope offers multiple functionalities, including accelerated mechanistic studies through digital twin QD synthesis modeling, closed‐loop autonomous optimization for accelerated QD synthetic route discovery, and on‐demand continuous manufacturing of high‐performing QDs. Through these developments, Smart Dope autonomously identifies the optimal synthetic route of Mn‐Yb co‐doped CsPbCl 3 QDs with a PLQY of 158%, which is the highest reported value for this class of QDs to date. Smart Dope illustrates the power of SDFLs in accelerating the discovery and development of emerging advanced energy materials. DA - 2023/11/12/ PY - 2023/11/12/ DO - 10.1002/aenm.202302303 VL - 11 SP - SN - 1614-6840 KW - autonomous experimentation KW - modular flow chemistry KW - multi-cation-doped perovskite quantum dots KW - self-driving labs ER - TY - JOUR TI - Cu-ATC vs. Cu-BTC: comparing the H2 adsorption mechanism through experiment, molecular simulation, and inelastic neutron scattering studies AU - Pham, Tony AU - Forrest, Katherine A. AU - Niu, Zheng AU - Tudor, Brant AU - Starkey, Chloe B. AU - Wang, Yue AU - Eddaoudi, Mohamed AU - Rosi, Nathaniel AU - Orcajo, Gisela AU - Eckert, Juergen AU - Ma, Shengqian AU - Space, Brian T2 - JOURNAL OF MATERIALS CHEMISTRY A AB - A combined experimental, inelastic neutron scattering, and theoretical study revealed that the metal–organic framework Cu-ATC exhibits greater H 2 adsorption affinity compared to the well-known Cu-BTC. DA - 2023/10/16/ PY - 2023/10/16/ DO - 10.1039/d3ta04748b VL - 10 SP - SN - 2050-7496 ER - TY - JOUR TI - Discovery of a Hybrid System for Photocatalytic CO2 Reduction via Attachment of a Molecular Cobalt-Quaterpyridine Complex to a Crystalline Carbon Nitride AU - McGuigan, Scott AU - Tereniak, Stephen J. AU - Donley, Carrie L. AU - Smith, Avery AU - Jeon, Sungho AU - Zhao, Fengyi AU - Sampaio, Renato N. AU - Pauly, Magnus AU - Keller, Landon AU - Collins, Leonard AU - Parsons, Gregory N. AU - Lian, Tianquan AU - Stach, Eric A. AU - Maggard, Paul A. T2 - ACS APPLIED ENERGY MATERIALS AB - While recent reports have demonstrated the attachment of molecular catalysts to amorphous, graphitic carbon nitrides (g-CN) for light-driven CO2 reduction, approaches to the utilization of crystalline carbon nitrides have remained undiscovered. Herein, a functional hybrid photocatalyst system has been found using a crystalline carbon nitride semiconductor, poly(triazine imide) lithium chloride (PTI-LiCl), with a surface-attached CoCl2(qpy-Ph-COOH) catalyst for CO2 reduction. The molecular catalyst attaches to PTI-LiCl at concentrations from 0.10 to 4.30 wt % and exhibits ∼96% selectivity for CO production in a CO2-saturated, aqueous 0.5 M KHCO3 solution. Optimal loadings were found to be within 0.42–1.04 wt % with rates between 1,400 and 1,550 μmol CO/g·h at an irradiance of 172 mW/cm2 (λ = 390 nm) and apparent quantum yields of ∼2%. This optimized loading is postulated to represent a balance between maximal turnover frequency (TOF; 300+ h–1) and excess catalyst that can limit excited-electron lifetimes, as probed via transient absorption spectroscopy. An increase in the incident irradiance yields a concomitant increase in the TOFs and CO rates only for the higher catalyst loadings, reaching up to 2,149 μmol CO/g·h with a more efficient use of the catalyst surface capacity. The lower catalyst loadings, by comparison, already function at maximal TOFs. Higher surface loadings are also found to help mitigate deactivation of the molecular catalysts during extended catalytic testing (>24 h) owing to the greater net surface capacity for CO2 reduction, thus representing an effective strategy to extend lifetime. The hybrid particles can be deposited onto an FTO substrate to yield ∼60% Faradaic efficiency for photoelectrochemical CO production at −1.2 V vs Ag/AgCl bias. In summary, these results demonstrate the synergistic combination of a crystalline carbon nitride with a molecular catalyst that achieves among the highest known rates in carbon-nitride systems for the light-driven CO2 reduction to CO in aqueous solution with >95% selectivity. DA - 2023/10/12/ PY - 2023/10/12/ DO - 10.1021/acsaem.3c01670 VL - 10 SP - SN - 2574-0962 KW - hybrid materials KW - photocatalysis KW - carbon nitride KW - CO2 reduction ER - TY - JOUR TI - Synthesis, characterization, computational studies, and reactivity of platinum(II) complexes of alkyl phosphite ligands AU - Grice, Kyle A. AU - Crespo, Edgar J. AU - Anselmo, Mirachelle M. AU - Bobrov, Sean F. AU - Farooqui, Farah T. AU - Lawando, Anthony E. AU - Sommer, Roger D. T2 - JOURNAL OF ORGANOMETALLIC CHEMISTRY AB - Air-stable phosphite-ligated platinum complexes of the form cis-Pt(P(OR)3)2Cl2 and cis-Pt(P(OR)3)2Me2 based on five small alkyl phosphite ligands have been synthesized and characterized. The crystal structures for several of these species are reported, allowing for comparison between spectroscopic and structural parameters. Michaelis-Arbuzov-type dealkylation during synthesis was observed for some of the phosphite ligands, and a dealkylated product was structurally characterized. Density Functional Theory (DFT) and Quantum Theory of Atoms in Molecules (QTAIM) was also used to examine the electronic structure of the phosphite compounds. The QTAIM results support the increased π-acidity of the phosphite ligands compared to analogous phosphines. Thermolysis experiments were performed to examine the stability and reactivity of Pt(P(OR)3)2X2 species. It was found that coordinated P(OiPr)3 ligands decompose via cyclometallation and propylene extrusion. DA - 2023/10/15/ PY - 2023/10/15/ DO - 10.1016/j.jorganchem.2023.122817 VL - 999 SP - SN - 1872-8561 KW - Organoplatinum(II) complexes KW - Phosphite ligands KW - X-ray crystallography KW - Computational chemistry ER - TY - JOUR TI - LIGHT-SABRE hyperpolarizes 1-13C-pyruvate continuously, without magnetic field cycling AU - Pravdivtsev, A.N. AU - Buckenmaier, K. AU - Kempf, N. AU - Stevanato, G. AU - Scheffler, K. AU - Engelmann, J. AU - Plaumann, M. AU - Koerber, R. AU - Hövener, J.-B. AU - Theis, T. T2 - arXiv AB - Nuclear spin hyperpolarization enables real-time observation of metabolism and intermolecular interactions in vivo. 1-13C-Pyruvate is the leading hyperpolarized tracer currently under evaluation in several clinical trials as a promising molecular imaging agent. Still, the quest for a simple, fast, and efficient hyperpolarization technique is ongoing. Here, we describe that continuous, weak irradiation in the audio-frequency range of the 13C spin at 121 {\mu}T magnetic field (\sim twiceEarth\apos s field) enables spin order transfer from parahydrogen to 13C magnetization of 1-13C-pyruvate. These so-called LIGHT-SABRE pulses couple nuclear spin states of parahydrogen and pyruvate via the J-coupling network of reversibly exchanging Ir-complexes. Using \sim 100% parahydrogen at ambient pressure, we polarized 51 mM of 1-13C-pyruvate in the presence of 5.1 mM Ir-complex continuously and repeatedly to a polarization of 1.1% averaged over free and catalyst-bound pyruvate. The experiments were conducted at -8{\deg}C), where almost exclusively bound pyruvate was observed, corresponding to an estimated 11% polarization on bound pyruvate. The obtained hyperpolarization levels closely match those obtained via SABRE-SHEATH under otherwise identical conditions. The creation of three different types of spin orders was observed: transverse 13C magnetization along the applied magnetic field, 13C z-magnetization along the main field B_0, and 13C-1H zz-spin-order. With a superconducting quantum interference device (SQUID) for detection, we found that the generated spin orders result from tiny 1H-13C J-coupling interactions, which are not visible even with our narrow linewidth below 0.3 Hz. DA - 2023/// PY - 2023/// DO - 10.48550/arXiv.2302.09299 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85149163371&partnerID=MN8TOARS ER - TY - JOUR TI - Facile hyperpolarization chemistry for molecular imaging and metabolic tracking of [1-13C]pyruvate in vivo AU - MacCulloch, K. AU - Browning, A. AU - Guarin Bedoya, D.O. AU - McBride, S.J. AU - Abdulmojeed, M.B. AU - Dedesma, C. AU - Goodson, B.M. AU - Rosen, M.S. AU - Chekmenev, E.Y. AU - Yen, Y.-F. AU - TomHon, P. AU - Theis, T. T2 - SSRN DA - 2023/// PY - 2023/// DO - 10.2139/ssrn.4504262 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85164574839&partnerID=MN8TOARS ER - TY - JOUR TI - Facile hyperpolarization chemistry for molecular imaging and metabolic tracking of [1-13C]pyruvate in vivo AU - Macculloch, Keilian AU - Browning, Austin AU - Bedoya, David O. Guarin AU - Mcbride, Stephen J. AU - Abdulmojeed, Mustapha B. AU - Dedesma, Carlos AU - Goodson, Boyd M. AU - Rosen, Matthew S. AU - Chekmenev, Eduard Y. AU - Yen, Yi-Fen AU - Tomhon, Patrick AU - Theis, Thomas T2 - JOURNAL OF MAGNETIC RESONANCE OPEN AB - Hyperpolarization chemistry based on reversible exchange of parahydrogen, also known as Signal Amplification By Reversible Exchange (SABRE), is a particularly simple approach to attain high levels of nuclear spin hyperpolarization, which can enhance NMR and MRI signals by many orders of magnitude. SABRE has received significant attention in the scientific community since its inception because of its relative experimental simplicity and its broad applicability to a wide range of molecules, however in vivo detection of molecular probes hyperpolarized by SABRE has remained elusive. Here we describe a first demonstration of SABRE-hyperpolarized contrast detected in vivo, specifically using hyperpolarized [1-13C]pyruvate. Biocompatible formulations of hyperpolarized [1-13C]pyruvate in, both, methanol-water mixtures, and ethanol-water mixtures followed by dilution with saline and catalyst filtration were prepared and injected into healthy Sprague Dawley and Wistar rats. Effective hyperpolarization-catalyst removal was performed with silica filters without major losses in hyperpolarization. Metabolic conversion of pyruvate to lactate, alanine, and bicarbonate was detected in vivo. Pyruvate-hydrate was also observed as minor byproduct. Measurements were performed on the liver and kidney at 4.7 T via time-resolved spectroscopy and chemical-shift-resolved MRI. In addition, whole-body metabolic measurements were obtained using a cryogen-free 1.5 T MRI system, illustrating the utility of combining lower-cost MRI systems with simple, low-cost hyperpolarization chemistry to develop safe, and scalable molecular imaging. DA - 2023/12// PY - 2023/12// DO - 10.1016/j.jmro.2023.100129 VL - 16-17 SP - SN - 2666-4410 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85168097895&partnerID=MN8TOARS KW - Hyperpolarized MRI KW - Parahydrogen KW - SABRE KW - Metabolic imaging ER - TY - JOUR TI - Delivering Robust Proton-Only Sensing of Hyperpolarized [1,2-13C2]-Pyruvate Using Broad-Spectral-Range Nuclear Magnetic Resonance Pulse Sequences AU - Mandzhieva, Iuliia AU - Adelabu, Isaiah AU - Nantogma, Shiraz AU - Chekmenev, Eduard Y. AU - Theis, Thomas T2 - ACS SENSORS AB - Hyperpolarized [1-13C]pyruvate is the leading hyperpolarized injectable contrast agent and is currently under evaluation in clinical trials for molecular imaging of metabolic diseases, including cardiovascular disease and cancer. One aspect limiting broad scalability of the technique is that hyperpolarized 13C MRI requires specialized 13C hardware and software that are not generally available on clinical MRI scanners, which employ proton-only detection. Here, we present an approach that uses pulse sequences to transfer 13C hyperpolarization to methyl protons for detection of the 13C-13C pyruvate singlet, employing proton-only excitation and detection only. The new pulse sequences are robust to the B1 and B0 magnetic field inhomogeneities. The work focuses on singlet-to-magnetization (S2M) and rotor-synchronized (R) pulses, both relying on trains of hard pulses with broad spectral width coverage designed to effectively transform hyperpolarized 13C2-singlet hyperpolarization to 1H polarization on the CH3 group of [1,2-13C2]pyruvate. This approach may enable a broader adoption of hyperpolarized MRI as a molecular imaging technique. DA - 2023/11/10/ PY - 2023/11/10/ DO - 10.1021/acssensors.3c01296 VL - 8 IS - 11 SP - 4101-4110 SN - 2379-3694 UR - https://doi.org/10.1021/acssensors.3c01296 KW - parahydrogen KW - hyperpolarization KW - pyruvate KW - SABRE KW - protonsensing KW - molecular imaging ER - TY - JOUR TI - Monitoring Molecules in Neuroscience AU - Sombers, Leslie A. T2 - ACS CHEMICAL NEUROSCIENCE AB - ADVERTISEMENT RETURN TO ISSUEEditorialNEXTMonitoring Molecules in NeuroscienceLeslie A. SombersLeslie A. SombersMore by Leslie A. SombersCite this: ACS Chem. Neurosci. 2023, 14, 20, 3726–3727Publication Date (Web):October 18, 2023Publication History Received12 September 2023Published online18 October 2023Published inissue 18 October 2023https://doi.org/10.1021/acschemneuro.3c00592Copyright © 2023 American Chemical SocietyRequest reuse permissions This publication is free to access through this site. Learn MoreArticle Views235Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-AlertscloseSUBJECTS:Amines,Central nervous system,Molecules,Receptors,Rodent models Get e-Alerts DA - 2023/10/18/ PY - 2023/10/18/ DO - 10.1021/acschemneuro.3c00592 VL - 14 IS - 20 SP - 3726-3727 SN - 1948-7193 ER - TY - JOUR TI - Identification and characterization of CHO host-cell proteins in monoclonal antibody bioprocessing AU - Oh, Young Hoon AU - Mendola, Kerri M. AU - Choe, Leila H. AU - Min, Lie AU - Lavoie, Ashton R. AU - Sripada, Sobhana A. AU - Williams, Taufika Islam AU - Lee, Kelvin H. AU - Yigzaw, Yinges AU - Seay, Alexander AU - Bill, Jerome AU - Li, Xuanwen AU - Roush, David J. AU - Cramer, Steven M. AU - Menegatti, Stefano AU - Lenhoff, Abraham M. T2 - BIOTECHNOLOGY AND BIOENGINEERING AB - Abstract Host‐cell proteins (HCPs) are the foremost class of process‐related impurities to be controlled and removed in downstream processing steps in monoclonal antibody (mAb) manufacturing. However, some HCPs may evade clearance in multiple purification steps and reach the final drug product, potentially threatening drug stability and patient safety. This study extends prior work on HCP characterization and persistence in mAb process streams by using mass spectrometry (MS)‐based methods to track HCPs through downstream processing steps for seven mAbs that were generated by five different cell lines. The results show considerable variability in HCP identities in the processing steps but extensive commonality in the identities and quantities of the most abundant HCPs in the harvests for different processes. Analysis of HCP abundance in the harvests shows a likely relationship between abundance and the reproducibility of quantification measurements and suggests that some groups of HCPs may hinder the characterization. Quantitative monitoring of HCPs persisting through purification steps coupled with the findings from the harvest analysis suggest that multiple factors, including HCP abundance and mAb‐HCP interactions, can contribute to the persistence of individual HCPs and the identification of groups of common, persistent HCPs in mAb manufacturing. DA - 2023/10/25/ PY - 2023/10/25/ DO - 10.1002/bit.28568 VL - 10 SP - SN - 1097-0290 KW - bioprocessing KW - Chinese hamster ovary cells KW - host-cell proteins KW - monoclonal antibodies KW - purification ER - TY - JOUR TI - Cation exchange route to a Eu(II)-containing tantalum oxide AU - O'Donnell, Shaun AU - Gabilondo, Eric AU - Jana, Subhendu AU - Koldemir, Aylin AU - Block, Theresa AU - Whangbo, Myung-Hwan AU - Kremer, Reinhard AU - Pottgen, Rainer AU - Maggard, Paul A. T2 - JOURNAL OF SOLID STATE CHEMISTRY AB - Traditional synthetic efforts to prepare Eu(II)-containing oxides have principally involved the use of high temperature reactions starting from EuO or a controlled, highly-reducing, atmosphere. Conversely, chimie douce approaches that are more amenable to the targeted syntheses of new, and potentially metastable, Eu(II)-oxides have yet to be explored. Herein, a cation-exchange route to new Eu(II)-containing oxides, e.g., EuTa4-xO11 (x = 0.04), has been discovered and its structure determined by powder X-ray diffraction (Space group P6322 (#182), a = 6.2539(2) Å; c = 12.3417(2) Å). The compound derives from the cation exchange of Na2Ta4O11, via a reaction with EuBr2 at 1173 K, and replacement by half the number of divalent Eu cations. Rietveld refinements show preferential ordering of the Eu cations over one of the two possible cation sites, i.e., Wyckoff site 2d (∼94%; Eu1) versus 2b (∼6%; Eu2). Total energy calculations confirm an energetic preference of the Eu cation in the 2d site. Tantalum vacancies of ∼1% occur within the layer of Eu cations and TaO6 octahedra, and ∼20% partial oxidation of Eu(II) to Eu(III) cations from charge balance considerations. 151Eu Mössbauer spectroscopy measured at 78 K found a Eu(II):Eu(III) ratio of 69:31, with a relatively broad line width of the former signal of Γ = 7.6(2) mm s–1. Also, the temperature-dependent magnetic susceptibility could be fitted to a Curie Weiss expression, giving a μeff = 6.2 μB and θCW = −10 K and confirming a mixture of Eu(II)/Eu(III) cations. The optical bandgap of EuTa4-xO11 was found to be ∼1.5 eV (indirect), significantly redshifted as compared to ∼4.1 eV for Na2Ta4O11. Spin-polarized electronic structure calculations show that this redshift stems from the addition of Eu 4f7 states as a higher-energy valence band. Thus, these results demonstrate a new cation-exchange approach that represents a useful synthetic pathway to new Eu(II)-containing oxides for tunable magnetic and optical properties. DA - 2023/12// PY - 2023/12// DO - 10.1016/j.jssc.2023.124338 VL - 328 SP - SN - 1095-726X ER - TY - JOUR TI - Low-rate smartphone videoscopy for microsecond luminescence lifetime imaging with machine learning AU - Wang, Yan AU - Sadeghi, Sina AU - Velayati, Alireza AU - Paul, Rajesh AU - Hetzler, Zach AU - Danilov, Evgeny AU - Ligler, Frances S. AU - Wei, Qingshan T2 - PNAS NEXUS AB - Time-resolved techniques have been widely used in time-gated and luminescence lifetime imaging. However, traditional time-resolved systems require expensive lab equipment such as high-speed excitation sources and detectors or complicated mechanical choppers to achieve high repetition rates. Here, we present a cost-effective and miniaturized smartphone lifetime imaging system integrated with a pulsed ultraviolet (UV) light-emitting diode (LED) for 2D luminescence lifetime imaging using a videoscopy-based virtual chopper (V-chopper) mechanism combined with machine learning. The V-chopper method generates a series of time-delayed images between excitation pulses and smartphone gating so that the luminescence lifetime can be measured at each pixel using a relatively low acquisition frame rate (e.g. 30 frames per second [fps]) without the need for excitation synchronization. Europium (Eu) complex dyes with different luminescent lifetimes ranging from microseconds to seconds were used to demonstrate and evaluate the principle of V-chopper on a 3D-printed smartphone microscopy platform. A convolutional neural network (CNN) model was developed to automatically distinguish the gated images in different decay cycles with an accuracy of >99.5%. The current smartphone V-chopper system can detect lifetime down to ∼75 µs utilizing the default phase shift between the smartphone video rate and excitation pulses and in principle can detect much shorter lifetimes by accurately programming the time delay. This V-chopper methodology has eliminated the need for the expensive and complicated instruments used in traditional time-resolved detection and can greatly expand the applications of time-resolved lifetime technologies. DA - 2023/9/29/ PY - 2023/9/29/ DO - 10.1093/pnasnexus/pgad313 VL - 2 IS - 10 SP - SN - 2752-6542 KW - smartphone videoscopy KW - V-chopper KW - time-resolved KW - lifetime imaging KW - machine learning ER - TY - JOUR TI - Using Multidimensional Separations to Distinguish Isomeric Amino Acid-Bile Acid Conjugates and Assess Their Presence and Perturbations in Model Systems AU - Stewart, Allison K. AU - Foley, Matthew H. AU - Dougherty, Michael K. AU - Mcgill, Sarah K. AU - Gulati, Ajay S. AU - Gentry, Emily C. AU - Hagey, Lee R. AU - Dorrestein, Pieter C. AU - Theriot, Casey M. AU - Dodds, James N. AU - Baker, Erin S. T2 - ANALYTICAL CHEMISTRY AB - Bile acids play key roles in nutrient uptake, inflammation, signaling, and microbiome composition. While previous bile acid analyses have primarily focused on profiling 5 canonical primary and secondary bile acids and their glycine and taurine amino acid–bile acid (AA–BA) conjugates, recent studies suggest that many other microbial conjugated bile acids (or MCBAs) exist. MCBAs are produced by the gut microbiota and serve as biomarkers, providing information about early disease onset and gut health. Here we analyzed 8 core bile acids synthetically conjugated with 22 proteinogenic and nonproteogenic amino acids totaling 176 MCBAs. Since many of the conjugates were isomeric and only 42 different m/z values resulted from the 176 MCBAs, a platform coupling liquid chromatography, ion mobility spectrometry, and mass spectrometry (LC–IMS–MS) was used for their separation. Their molecular characteristics were then used to create an in-house extended bile acid library for a combined total of 182 unique compounds. Additionally, ∼250 rare bile acid extracts were also assessed to provide additional resources for bile acid profiling and identification. This library was then applied to healthy mice dosed with antibiotics and humans having fecal microbiota transplantation (FMT) to assess the MCBA presence and changes in the gut before and after each perturbation. DA - 2023/10/5/ PY - 2023/10/5/ DO - 10.1021/acs.analchem.3c03057 VL - 95 IS - 41 SP - 15357-15366 SN - 1520-6882 ER - TY - JOUR TI - Evaluating the optimal tissue thickness for mass spectrometry imaging using infrared matrix-assisted laser desorption electrospray ionization AU - Joignant, Alena N. AU - Knizner, Kevan T. AU - Xi, Ying AU - Muddiman, David C. T2 - RAPID COMMUNICATIONS IN MASS SPECTROMETRY AB - Rationale Infrared matrix‐assisted laser desorption electrospray ionization (IR‐MALDESI) utilizes a 2970 nm mid‐IR laser to desorb samples with depth resolutions ( Z ) on the order of micrometers. Conventionally, 5–20 μm thick tissue sections are used to characterize different applications of the IR‐MALDESI source, but an optimal thickness has not been systematically investigated. Methods Mouse liver was sectioned to various thicknesses and analyzed using IR‐MALDESI mass spectrometry imaging (MSI). Height profiles of tissue sections of various cryosectioned thicknesses were acquired to affirm tissue thickness. Tissue sections of each thickness were measured using a Keyence microscope. Paraffin wax was cryosectioned, mounted on microscope slides, and measured using a chromatic confocal sensor system to determine the cryostat sectioning accuracy. Results Analyzing sectioned tissues at higher thickness (>10 μm) leads to lower ion abundance, a decrease in signal over long analysis times, and more frequent instrument cleaning. Additionally, increasing tissue thickness above the optimum (7 μm) does not result in a significant increase in lipid annotations. Conclusions This work defines an optimal sample thickness for IR‐MALDESI‐MSI and demonstrates the utility of optimizing tissue thickness for MSI platforms of comparable Z resolution. DA - 2023/11/30/ PY - 2023/11/30/ DO - 10.1002/rcm.9638 VL - 37 IS - 22 SP - SN - 1097-0231 ER - TY - JOUR TI - Variation from closed-shell to open shell electronic structures in oligothiophene bis(dioxolene) complexes AU - Miller, Paul D. AU - Shultz, David A. AU - Mengell, Joshua AU - Kirk, Martin L. AU - Wojtas, Lukasz T2 - CHEMICAL SCIENCE AB - A symmetry-based model that explicitly includes the bridge fragment is used to explain a continuum of electronic structures for Kekulé-type biradicals. DA - 2023/10/9/ PY - 2023/10/9/ DO - 10.1039/D3SC02341A VL - 10 SP - SN - 2041-6539 UR - https://doi.org/10.1039/D3SC02341A ER - TY - JOUR TI - Pseudo-affinity capture of K. phaffii host cell proteins in flow-through mode: Purification of protein therapeutics and proteomic study AU - Sripada, Sobhana A. AU - Elhanafi, Driss AU - Collins, Leonard B. AU - Williams, Taufika I. AU - Linova, Marina Y. AU - Woodley, John M. AU - Boi, Cristiana AU - Menegatti, Stefano T2 - SEPARATION AND PURIFICATION TECHNOLOGY AB - K. phaffii is a versatile expression system that is increasingly utilized to produce biological therapeutics – including enzymes, engineered antibodies, and gene-editing tools – that feature multiple subunits and complex post-translational modifications. Two major roadblocks limit the adoption of K. phaffii in industrial biomanufacturing: its proteome, while known, has not been linked to downstream process operations and detailed knowledge is missing on problematic host cell proteins (HCPs) that endanger patient safety or product stability. Furthermore, the purification toolbox has not evolved beyond the capture of monospecific antibodies, and few solutions are available for engineered antibody fragments and other protein therapeutics. To unlock the potential of yeast-based biopharmaceutical manufacturing, this study presents the development and performance validation of a novel adsorbent – PichiaGuard – functionalized with peptide ligands that target the whole spectrum of K. phaffii HCPs and designed for protein purification in flow-through mode. The PichiaGuard adsorbent features high HCP binding capacity (∼25 g per liter of resin) and successfully purified a monoclonal antibody and an ScFv fragment from clarified K. phaffii harvests, affording > 300-fold removal of HCPs and high product yields (70–80%). Notably, PichiaGuard outperformed commercial ion exchange and mixed-mode resins without salt gradients or optimization in removing high-risk HCPs – including aspartic proteases, ribosomal subunits, and other peptidases – thus demonstrating its value in modern biopharmaceutical processing. DA - 2023/12/1/ PY - 2023/12/1/ DO - 10.1016/j.seppur.2023.124777 VL - 326 SP - SN - 1873-3794 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85169830823&partnerID=MN8TOARS KW - Komagataella phaffii KW - Chromatography KW - Protein purification KW - Monoclonal antibodies KW - Antibody fragment KW - Proteomics ER - TY - JOUR TI - Well-Defined Iron Sites in Crystalline Carbon Nitride AU - Genoux, Alexandre AU - Pauly, Magnus AU - Rooney, Conor L. AU - Choi, Chungseok AU - Shang, Bo AU - McGuigan, Scott AU - Fataftah, Majed S. AU - Kayser, Yves AU - Suhr, Simon C. B. AU - Debeer, Serena AU - Wang, Hailiang AU - Maggard, Paul A. AU - Holland, Patrick L. T2 - JOURNAL OF THE AMERICAN CHEMICAL SOCIETY AB - Carbon nitride materials can be hosts for transition metal sites, but Mössbauer studies on iron complexes in carbon nitrides have always shown a mixture of environments and oxidation states. Here we describe the synthesis and characterization of a crystalline carbon nitride with stoichiometric iron sites that all have the same environment. The material (formula C6N9H2Fe0.4Li1.2Cl, abbreviated PTI/FeCl2) is derived from reacting poly(triazine imide)·LiCl (PTI/LiCl) with a low-melting FeCl2/KCl flux, followed by anaerobic rinsing with methanol. X-ray diffraction, X-ray absorption and Mössbauer spectroscopies, and SQUID magnetometry indicate that there are tetrahedral high-spin iron(II) sites throughout the material, all having the same geometry. The material is active for electrocatalytic nitrate reduction to ammonia, with a production rate of ca. 0.1 mmol cm–2 h–1 and Faradaic efficiency of ca. 80% at −0.80 V vs RHE. DA - 2023/9/13/ PY - 2023/9/13/ DO - 10.1021/jacs.3c05417 VL - 145 IS - 38 SP - 20739-20744 SN - 1520-5126 ER - TY - JOUR TI - Switching Lead for Tin in PbHfO3: Noncubic Structure of SnHfO3 AU - Gabilondo, Eric A. AU - Newell, Ryan J. AU - Broughton, Rachel AU - Koldemir, Aylin AU - Poettgen, Rainer AU - Jones, Jacob L. AU - Maggard, Paul A. T2 - ANGEWANDTE CHEMIE-INTERNATIONAL EDITION AB - The removal of lead from commercialized perovskite-oxide-based piezoceramics has been a recent major topic in materials research owing to legislation in many countries. In this regard, Sn(II)-perovskite oxides have garnered keen interest due to their predicted large spontaneous electric polarizations and isoelectronic nature for substitution of Pb(II) cations. However, they have not been considered synthesizable owing to their high metastability. Herein, the perovskite lead hafnate, i.e., PbHfO3 in space group Pbam, is shown to react with SnClF at a low temperature of 300 °C, and resulting in the first complete Sn(II)-for-Pb(II) substitution, i.e. SnHfO3 . During this topotactic transformation, a high purity and crystallinity is conserved with Pbam symmetry, as confirmed by X-ray and electron diffraction, elemental analysis, and 119 Sn Mössbauer spectroscopy. In situ diffraction shows SnHfO3 also possesses reversible phase transformations and is potentially polar between ≈130-200 °C. This so-called 'de-leadification' is thus shown to represent a highly useful strategy to fully remove lead from perovskite-oxide-based piezoceramics and opening the door to new explorations of polar and antipolar Sn(II)-oxide materials. DA - 2023/9/25/ PY - 2023/9/25/ DO - 10.1002/anie.202312130 VL - 9 SP - SN - 1521-3773 KW - Ion Exchange KW - Metastable Compounds KW - Perovskite Phases ER - TY - JOUR TI - Ferrous and ferric complexes with cyclometalating N-heterocyclic carbene ligands: a case of dual emission revisited AU - Johnson, Catherine Ellen AU - Schwarz, Jesper AU - Deegbey, Mawuli AU - Prakash, Om AU - Sharma, Kumkum AU - Huang, Ping AU - Ericsson, Tore AU - Haggstrom, Lennart AU - Bendix, Jesper AU - Gupta, Arvind Kumar AU - Jakubikova, Elena AU - Warnmark, Kenneth AU - Lomoth, Reiner T2 - CHEMICAL SCIENCE AB - Photoluminescence of the Fe III complex occurs only from its 2 LMCT state while its higher-energy but shorter-lived 2 MLCT state is non-luminescent. Blue emission arises instead from a photoproduct of the non-emitting Fe II complex. DA - 2023/9/27/ PY - 2023/9/27/ DO - 10.1039/d3sc02806b VL - 14 IS - 37 SP - 10129-10139 SN - 2041-6539 ER - TY - JOUR TI - Design and Implementation of an Accessible and Open-Sourced In Silico Drug Screening Activity for Cancer Drug Discovery AU - Fikes, Audrey G. AU - Srougi, Melissa C. T2 - JOURNAL OF CHEMICAL EDUCATION AB - The application of chemistry concepts in biological settings plays an important role in the interdisciplinary field of drug discovery and development. This is true for molecular docking, where an understanding of intermolecular forces and noncovalent interactions is useful for rational drug design and development. Here we report the design and use of a molecular docking activity for cancer drug discovery for users that requires minimal coding knowledge. Although used in a drug discovery context, this activity can be incorporated into a range of undergraduate/graduate chemistry and biochemistry courses either as a stand-alone activity or integrated into existing curricula. The activity uses AutoDock Vina, AutoDockTools, Strawberry Perl, and PyMOL, all of which are free, open-source software. The activity is used to carry out molecular docking of multiple ligands at once and predict the binding energy of hits identified from a high-throughput drug repurposing screen against a target enzyme overexpressed in human tumors. Students analyze their docking results to determine drugs that should go on to further in vitro testing based on the predicted noncovalent ligand–protein interactions. This activity serves as an introduction to molecular docking and as a review of intermolecular forces, highlighting their importance in biological fields. DA - 2023/9/19/ PY - 2023/9/19/ DO - 10.1021/acs.jchemed.3c00307 VL - 100 IS - 10 SP - 4125-4130 SN - 1938-1328 KW - Graduate Education/Research KW - Upper-Division Undergraduate KW - Interdisciplinary/Multidisciplinary KW - Biochemistry KW - Chemoinformatics KW - Computer-Based Learning KW - Internet/Web-Based Learning KW - Biotechnology KW - Drugs/Pharmaceuticals KW - Molecular Modeling ER - TY - JOUR TI - Electron spin resonance in emerging spin-driven applications: Fundamentals and future perspectives AU - Polash, Md Mobarak Hossain AU - Smirnov, Alex I. AU - Vashaee, Daryoosh T2 - APPLIED PHYSICS REVIEWS AB - Spin, the intrinsic angular momentum of an electron, is increasingly being recognized as a versatile tool in the development of next-generation technologies, including quantum computing, sensing, and communication, which exploit quantum phenomena. The burgeoning theoretical understanding coupled with technological advancements have catalyzed research efforts aimed at controlling and manipulating the optical, electrical, magnetic, and thermal properties of materials through the modulation of spin states. Among the myriad of techniques available for investigating these spin-dependent properties, Electron Spin Resonance (ESR), sometimes referred to as electron paramagnetic resonance, stands out as one of the most direct and potent methods to probe electron spin dynamics irrespective of the material environment. ESR furnishes insightful data on the states of individual spins and clusters, spin coherence via relaxation time measurements, and inter-spin distances from spin–spin interaction measurements. Additionally, ESR facilitates the manipulation of spin systems by tailoring the Zeeman energy through the modulation of the external magnetic field, and critically, by the remote manipulation of spins via the application of microwave pulses at resonance frequencies. Modern ESR experimental setups are versatile and can be employed across a wide temperature spectrum—from a few Kelvin, where quantum effects are pronounced, to room temperature and beyond. This adaptability enhances the utility of ESR in investigating the spin-dependent properties in condensed matter systems. Notwithstanding the tremendous potential and advantages that ESR offers, it remains underutilized, especially when compared to inelastic neutron scattering (INS) and nuclear magnetic resonance, despite the latter being more expensive and INS being less accessible. In this review, we elucidate the fundamental principles of ESR, with an emphasis on magnetic and spin interactions in solids, and explore the potential of ESR in advancing the understanding of spin properties across a diverse array of materials science disciplines. We commence with a concise introduction to spin-related physics, followed by the application of ESR in characterizing spin systems. As such, this review aims to serve as a valuable resource for a broad audience, ranging from novices to experts, who are keen on unraveling spin phenomena and dynamics in materials science and condensed matter physics. DA - 2023/12// PY - 2023/12// DO - 10.1063/5.0072564 VL - 10 IS - 4 SP - SN - 1931-9401 UR - https://doi.org/10.1063/5.0072564 ER - TY - JOUR TI - Carbon Nanotubes for Optical Detection of Quaternary Ammonium Compounds in Complex Media AU - Dewey, Hannah M. AU - Jones, Jaron AU - Lucas, Sydney AU - Hall, Shelby AU - Sultana, Nigar AU - Abello, Sofia Mariapaz AU - Budhathoki-Uprety, Januka T2 - ACS APPLIED NANO MATERIALS AB - Quaternary ammonium compounds (QACs) are widely used in disinfectants, cleaners, preservatives, cosmetics, and agriculture. Recently, QACs have been detected in the human bloodstream, breast milk, and neonatal mouse brain, which shows that these compounds can cross biological barriers. In vivo studies showed that chronic low-level exposure to QACs causes developmental, reproductive, and immune dysfunctions, whereas in vitro studies indicate that QACs can affect reproductive systems, disrupt cholesterol biosynthesis, increase inflammatory cytokines, and decrease mitochondrial functions. Effects of QACs on health are gradually emerging, amid increased use of QAC disinfectants during the COVID-19 pandemic. Analysis of biological fluids including blood, urine, sweat, and saliva can provide vital information in determining the biological effects of analytes. Biofluid analysis is convenient yet crucial because of non-invasive/or minimally invasive procedures that can be performed outside hospital settings. Interest in optical detection methods for biofluid analysis has been growing due to recent advances in detection technologies and availability of tunable materials to aid the technologies. Detection in the near-infrared (NIR) spectral range is advantageous over the visible range mainly due to minimal autofluorescence, light-scattering, and absorption from native biological molecules in the NIR range. Photoluminescent single-walled carbon nanotubes (SWCNTs) are promising candidates for the development of NIR optical probes and sensors due to their non-photobleaching NIR fluorescence, tunable surface chemistry, and high sensitivity. Herein, we report optical detection of QACs in protein-rich media and a model biofluid. We functionalized photoluminescent SWCNTs with bile salt derivatives that enabled the detection of QACs in artificial sweat and serum-protein-enriched media. The QAC detection was significant at nanomolar concentrations, which is within the threshold that can affect various physiological processes. Thus, nanotube-based optical detection could be well suited for the analysis of QACs in biological fluids. DA - 2023/8/29/ PY - 2023/8/29/ DO - 10.1021/acsanm.3c02219 VL - 6 IS - 17 SP - 15530-15539 SN - 2574-0970 UR - https://doi.org/10.1021/acsanm.3c02219 KW - disinfectants KW - COVID-19 pandemic KW - quaternaryammonium compounds (QACs) KW - single-walled carbon nanotubes(SWCNTs) KW - nanosensor KW - human health KW - near-infraredprobe ER - TY - JOUR TI - Iron-sensitive protein conjugates formed with a Wittig reaction precursor in ionic liquid AU - Nizam, Zeinab M. AU - Stowe, Ashton M. AU - Mckinney, Jada K. AU - Ohata, Jun T2 - CHEMICAL COMMUNICATIONS DA - 2023/9/15/ PY - 2023/9/15/ DO - 10.1039/d3cc03825 VL - 9 SP - SN - 1364-548X ER - TY - JOUR TI - Current State-of-the-Art Toward Chemoenzymatic Synthesis of Polyketide Natural Products AU - Paulsel, Thaddeus Q. AU - Williams, Gavin J. T2 - CHEMBIOCHEM AB - Polyketide natural products have significant promise as pharmaceutical targets for human health and as molecular tools to probe disease and complex biological systems. While the biosynthetic logic of polyketide synthases (PKS) is well-understood, biosynthesis of designer polyketides remains challenging due to several bottlenecks, including substrate specificity constraints, disrupted protein-protein interactions, and protein solubility and folding issues. Focusing on substrate specificity, PKSs are typically interrogated using synthetic thioesters. PKS assembly lines and their products offer a wealth of information when studied in a chemoenzymatic fashion. This review provides an overview of the past two decades of polyketide chemoenzymatic synthesis and their contributions to the field of chemical biology. These synthetic strategies have successfully yielded natural product derivatives while providing critical insights into enzymatic promiscuity and mechanistic activity. DA - 2023/9/15/ PY - 2023/9/15/ DO - 10.1002/cbic.202300386 VL - 9 SP - SN - 1439-7633 UR - https://doi.org/10.1002/cbic.202300386 KW - bioorganic chemistry KW - biosynthesis KW - enzymes KW - polyketides KW - synthetic biology ER - TY - JOUR TI - An S=1 Iron(IV) Intermediate Revealed in a Non-Heme Iron Enzyme-Catalyzed Oxidative C-S Bond Formation AU - Paris, Jared C. AU - Hu, Sha AU - Wen, Aiwen AU - Weitz, Andrew C. AU - Cheng, Ronghai AU - Gee, Leland B. AU - Tang, Yijie AU - Kim, Hyomin AU - Vegas, Arturo AU - Chang, Wei-chen AU - Elliott, Sean J. AU - Liu, Pinghua AU - Guo, Yisong T2 - ANGEWANDTE CHEMIE-INTERNATIONAL EDITION AB - Ergothioneine (ESH) and ovothiol A (OSHA) are two natural thiol-histidine derivatives. ESH has been implicated as a longevity vitamin and OSHA inhibits the proliferation of hepatocarcinoma. The key biosynthetic step of ESH and OSHA in the aerobic pathways is the O2 -dependent C-S bond formation catalyzed by non-heme iron enzymes (e.g., OvoA in ovothiol biosynthesis), but due to the lack of identification of key reactive intermediate the mechanism of this novel reaction is unresolved. In this study, we report the identification and characterization of a kinetically competent S=1 iron(IV) intermediate supported by a four-histidine ligand environment (three from the protein residues and one from the substrate) in enabling C-S bond formation in OvoA from Methyloversatilis thermotoleran, which represents the first experimentally observed intermediate spin iron(IV) species in non-heme iron enzymes. Results reported in this study thus set the stage to further dissect the mechanism of enzymatic oxidative C-S bond formation in the OSHA biosynthesis pathway. They also afford new opportunities to study the structure-function relationship of high-valent iron intermediates supported by a histidine rich ligand environment. DA - 2023/9/13/ PY - 2023/9/13/ DO - 10.1002/anie.202309362 VL - 9 SP - SN - 1521-3773 KW - Ergothioneine KW - Ferryl Intermediates KW - High-Valent Iron KW - Ovothiol A KW - Oxidative C-S Bond Formation ER - TY - JOUR TI - Palladium-Catalyzed Decarbonylative Coupling of (Hetero)Aryl Boronate Esters with Difluorobenzyl Glutarimides AU - Bunnell, Alexander AU - Lalloo, Naish AU - Brigham, Conor AU - Sanford, Melanie S. T2 - Organic Letters AB - This report describes the Pd-catalyzed decarbonylative coupling of difluorobenzyl glutarimides with (hetero)aryl boronate esters to yield difluorobenzyl-substituted (hetero)arene products. The use of PAd2Bu as the phosphine ligand in combination with neopentylboronate ester nucleophiles proved critical for the selective formation of the decarbonylative coupling product versus analogous difluorobenzyl ketone. This transformation is effective for electronically diverse (hetero)aryl boronate esters and substituted difluorobenzyl glutarimides. DA - 2023/10/20/ PY - 2023/10/20/ DO - 10.1021/acs.orglett.3c03071 UR - https://doi.org/10.1021/acs.orglett.3c03071 ER - TY - JOUR TI - Sterically Encumbered Heteroleptic Copper(I) β-Diketiminate Complexes with Extended Excited-State Lifetimes AU - Kim, Dooyoung AU - Rosko, Michael C. AU - Dang, Vinh Q. AU - Castellano, Felix N. AU - Teets, Thomas S. T2 - INORGANIC CHEMISTRY AB - One of the main challenges in developing effective copper(I) photosensitizers is their short excited-state lifetimes, usually attributed to structural distortion upon light excitation. We have previously introduced copper(I) charge-transfer chromophores of the general formula Cu(N^N)(ArNacNac), where N^N is a conjugated diimine ligand and ArNacNac is a substituted β-diketiminate ligand. These chromophores were promising regarding their tunable redox potentials and intense visible absorption but were ineffective as photosensitizers, presumably due to short excited-state lifetimes. Here, we introduce sterically crowded analogues of these heteroleptic chromophores with bulky alkyl substituents on the N^N and/or ArNacNac ligand. Structural analysis was combined with electrochemical and photophysical characterization, including ultrafast transient absorption (UFTA) spectroscopy to investigate the effects of the alkyl groups on the excited-state lifetimes of the complexes. The molecular structures determined by single-crystal X-ray diffraction display more distortion in the ground state as alkyl substituents are introduced into the phenanthroline or the NacNac ligand, showing smaller τ4 values due to the steric hindrance. UFTA measurements were carried out to determine the excited-state dynamics. Sterically encumbered Cu5 and Cu6 display excited-state lifetimes 15-20 times longer than unsubstituted complex Cu1, likely indicating that the incorporation of bulky alkyl substituents inhibits the pseudo-Jahn-Teller (PJT) flattening distortion in the excited state. This work suggests that the steric properties of these heteroleptic copper(I) charge-transfer chromophores can be readily modified and that the excited-state dynamics are strongly responsive to these modifications. DA - 2023/10/2/ PY - 2023/10/2/ DO - 10.1021/acs.inorgchem.3c02042 VL - 10 SP - SN - 1520-510X UR - https://doi.org/10.1021/acs.inorgchem.3c02042 ER - TY - JOUR TI - Isoform-specific optical activation of kinase function reveals p38-ERK signaling crosstalk AU - Zhou, Wenyuan AU - Ryan, Amy AU - Janosko, Chasity P. AU - Shoger, Karsen E. AU - Haugh, Jason M. AU - Gottschalk, Rachel A. AU - Deiters, Alexander T2 - RSC CHEMICAL BIOLOGY DA - 2023/8/25/ PY - 2023/8/25/ DO - 10.1039/d2cb00157 SP - SN - 2633-0679 ER - TY - JOUR TI - Tolyporphins-Exotic Tetrapyrrole Pigments in a Cyanobacterium-A Review AU - Nguyen, Kathy-Uyen AU - Zhang, Yunlong AU - Liu, Qihui AU - Zhang, Ran AU - Jin, Xiaohe AU - Taniguchi, Masahiko AU - Miller, Eric S. AU - Lindsey, Jonathan S. T2 - MOLECULES AB - Tolyporphins were discovered some 30 years ago as part of a global search for antineoplastic compounds from cyanobacteria. To date, the culture HT-58-2, comprised of a cyanobacterium–microbial consortium, is the sole known producer of tolyporphins. Eighteen tolyporphins are now known—each is a free base tetrapyrrole macrocycle with a dioxobacteriochlorin (14), oxochlorin (3), or porphyrin (1) chromophore. Each compound displays two, three, or four open β-pyrrole positions and two, one, or zero appended C-glycoside (or –OH or –OAc) groups, respectively; the appended groups form part of a geminal disubstitution motif flanking the oxo moiety in the pyrroline ring. The distinct structures and repertoire of tolyporphins stand alone in the large pigments-of-life family. Efforts to understand the cyanobacterial origin, biosynthetic pathways, structural diversity, physiological roles, and potential pharmacological properties of tolyporphins have attracted a broad spectrum of researchers from diverse scientific areas. The identification of putative biosynthetic gene clusters in the HT-58-2 cyanobacterial genome and accompanying studies suggest a new biosynthetic paradigm in the tetrapyrrole arena. The present review provides a comprehensive treatment of the rich science concerning tolyporphins. DA - 2023/8// PY - 2023/8// DO - 10.3390/molecules28166132 VL - 28 IS - 16 SP - SN - 1420-3049 UR - https://doi.org/10.3390/molecules28166132 KW - bacteriochlorin KW - bioinformatics KW - biosynthesis KW - chlorophyll KW - cyanobacteria KW - field biology KW - gene cluster KW - genomics KW - natural products KW - tolyporphins ER - TY - JOUR TI - Chemical labeling strategies using biomolecule-compatible, nonaqueous media AU - Ohata, Jun DA - 2023/9/27/ PY - 2023/9/27/ DO - 10.48321/D1536T M3 - [Data Management Plan]. DMPTool. UR - https://doi.org/10.48321/D1536T ER - TY - JOUR TI - Comparative analysis of sucrose-embedding for whole-body zebrafish MSI by IR-MALDESI AU - Wang, Mary F. AU - Ritter, Morgan M. AU - Kullman, Seth W. AU - Muddiman, David C. T2 - ANALYTICAL AND BIOANALYTICAL CHEMISTRY DA - 2023/8/29/ PY - 2023/8/29/ DO - 10.1007/s00216-023-04914-1 VL - 8 SP - SN - 1618-2650 KW - IR-MALDESI KW - Mass spectrometry imaging KW - Sucrose KW - PFA KW - Zebrafish ER - TY - JOUR TI - Preventing the spread of life-threatening gastrointestinal microbes on the surface of a continuously self-disinfecting block polymer AU - Wells, Kacie M. AU - Ciftci, Yusuf AU - Peddinti, Bharadwaja S. T. AU - Ghiladi, Reza A. AU - Vediyappan, Govindsamy AU - Spontak, Richard J. AU - Govind, Revathi T2 - JOURNAL OF COLLOID AND INTERFACE SCIENCE AB - Highly persistent, drug-resistant and transmissible healthcare pathogens such as Clostridioides difficile (C. difficile) and Candida auris (C. auris) are responsible for causing antibiotic-associated fatal diarrhea and invasive candidiasis, respectively. In this study, we demonstrate that these potentially lethal gastrointestinal microbes can be rapidly inactivated on the solid surface of a self-disinfecting anionic block polymer that inherently generates a water surface layer that is highly acidic (pH < 1) upon hydration. Due to thermodynamic incompatibility between its chemical sequences, the polymer spontaneously self-organizes into a nanostructure that enables proton migration from the interior of a film to the surface via contiguous nanoscale hydrophilic channels, as discerned here by scanning electron and atomic force microscopies, as well as X-ray photoelectron spectroscopy. Here, we report that two strains of C. difficile in the vegetative state and two species of Candida, Candida albicans (C. albicans) and C. auris, are, in most cases, inactivated to the limit of minimum detection. Corresponding electron and optical microscopy images reveal that, upon exposure to the hydrated polymer, the outer microbial membranes display evidence of damage and intracellular material is expelled. Combined with our previous studies of rapid bacterial and viral inactivation, these antimicrobial results are highly encouraging and, if translatable to clinical conditions in the form of self-standing polymer films or coatings, are expected to benefit the welfare of patients in healthcare facilities by continuously preventing the spread of these potentially dangerous microbes. DA - 2023/12/15/ PY - 2023/12/15/ DO - 10.1016/j.jcis.2023.08.088 VL - 652 SP - 718-726 SN - 1095-7103 KW - Anionic block polymer KW - Clostridioides difficile KW - Candida auris KW - Candida albicans KW - Antimicrobial KW - Self-disinfecting KW - Broad-spectrum KW - Infection prevention ER - TY - JOUR TI - Competitive reversed quartet mechanisms for photogenerated ground state electron spin polarization AU - Kirk, Martin L. AU - Shultz, David A. AU - Hewitt, Patrick AU - Marri, Anil Reddy AU - Est, Art T2 - CHEMICAL SCIENCE DA - 2023/8/8/ PY - 2023/8/8/ DO - 10.1039/d3sc03049 VL - 8 SP - SN - 2041-6539 ER - TY - JOUR TI - Iron-sensitive protein conjugates formed with a Wittig reaction precursor in ionic liquid AU - Nizam, Zeinab M. AU - Stowe, Ashton M. AU - Mckinney, Jada K. AU - Ohata, Jun T2 - CHEMICAL COMMUNICATIONS AB - In this report, formation of protein conjugates with an iron-sensitive enamine linkage is demonstrated through the ionic liquid-based bioconjugation method. DA - 2023/10/10/ PY - 2023/10/10/ DO - 10.1039/D3CC03825D VL - 59 IS - 81 SP - 12160-12163 SN - 1364-548X UR - https://doi.org/10.1039/D3CC03825D ER - TY - JOUR TI - Tribotronic and electrochemical properties of platinum-nanofluid interfaces formed by aqueous suspensions of 5 and 40 nm TiO2 nanoparticles AU - Seed, C. M. AU - Acharya, B. AU - Nunn, N. AU - Smirnov, A. I. AU - Krim, J. T2 - JOURNAL OF CHEMICAL PHYSICS AB - Nanoparticles (NPs) can be highly beneficial as additives to lubricating fluids, and the tribotronic response of charged NPs tuned by external fields represents an area of great technological potential. Tribotronic response, however, is expected to be highly size dependent, which represents a significant design challenge. To explore this issue, quartz crystal microbalance and cyclic voltammetry were employed to characterize nanotribological and electrochemical behavior of platinum-nanofluid interfaces formed by aqueous suspensions of different-sized negatively charged titanium dioxide (TiO2) NPs. Suspensions of 5, 40, and 100 nm NPs were all observed to reduced interfacial frictional drag forces upon introduction into pure water in zero field conditions, with reductions for the 40 nm NPs about twice those of 5 nm particles at comparable concentrations. Suspensions of 100 nm NPs produced even greater reductions, but rapidly precipitated from the suspension when left unstirred. NPs were also driven to and from Pt electrode surfaces by applying external electric fields with varying amplitudes and modulation frequencies. For electric fields of sufficient amplitude and duration, the 40 nm TiO2 nanosuspension exhibited tribological properties consistent with a reversible electrophoretic deposition of the NPs, accompanied by changes in the electrochemical attributes and increasing interfacial drag. The 5 nm NP properties were consistent with progressive reductions in interfacial drag forces at the NP-suspension interface linked to field-induced increases in concentration. DA - 2023/9/21/ PY - 2023/9/21/ DO - 10.1063/5.0155504 VL - 159 IS - 11 SP - SN - 1089-7690 UR - https://doi.org/10.1063/5.0155504 ER - TY - JOUR TI - Ferrous and ferric complexes with cyclometalating N-heterocyclic carbene ligands: a case of dual emission revisited AU - Johnson, Catherine Ellen AU - Schwarz, Jesper AU - Deegbey, Mawuli AU - Prakash, Om AU - Sharma, Kumkum AU - Huang, Ping AU - Ericsson, Tore AU - Haggstrom, Lennart AU - Bendix, Jesper AU - Gupta, Arvind Kumar AU - Jakubikova, Elena AU - Warnmark, Kenneth AU - Lomoth, Reiner T2 - CHEMICAL SCIENCE DA - 2023/8/29/ PY - 2023/8/29/ DO - 10.1039/d3sc02806 VL - 8 SP - SN - 2041-6539 ER - TY - CHAP TI - Core chromophores of native photosynthetic pigments AU - Lindsey, Jonathan S. AU - Taniguchi, Masahiko T2 - Photosynthesis A2 - Hou, J.M.H. A2 - Allakhverdiev, S.I. AB - The patina of pigments that envelops Earth and enables photosynthesis to power the biosphere is chiefly comprised of chlorophylls and bacteriochlorophylls. Such pigments, which contain a porphyrin, chlorin, or bacteriochlorin chromophore, underpin a rich collection of fundamental phenomena: absorption of ambient light, excited-state energy and electron transfer, and ground-state electron and hole transfer. The present chapter (1) outlines the chemical synthesis of naked porphyrin, chlorin, and bacteriochlorin macrocycles that are devoid of peripheral substituents, and (2) compares the absorption spectra of the naked chromophores with those of the native macrocycles. The synthetic and comparative spectral studies provide the basis for deep insight into the features of the native chlorophylls and bacteriochlorophylls, which are deservedly regarded as celestial molecules in the photosciences firmament. PY - 2023/// DO - 10.1016/b978-0-323-98391-4.00021-6 VL - 3 SP - 33–48 PB - Elsevier UR - http://dx.doi.org/10.1016/b978-0-323-98391-4.00021-6 ER - TY - JOUR TI - A Ferric-Superoxide Intermediate Initiates P450-Catalyzed Cyclic Dipeptide Dimerization AU - Gering, Hannah E. AU - Li, Xiaojun AU - Tang, Haoyu AU - Swartz, Paul D. AU - Chang, Wei-Chen AU - Makris, Thomas M. T2 - JOURNAL OF THE AMERICAN CHEMICAL SOCIETY AB - The cytochrome P450 (CYP) AspB is involved in the biosynthesis of the diketopiperazine (DKP) aspergilazine A. Tryptophan-linked dimeric DKP alkaloids are a large family of natural products that are found in numerous species and exhibit broad and often potent bioactivity. The proposed mechanisms for C-N bond formation by AspB, and similar C-C bond formations by related CYPs, have invoked the use of a ferryl-intermediate as an oxidant to promote substrate dimerization. Here, the parallel application of steady-state and transient kinetic approaches reveals a very different mechanism that involves a ferric-superoxide species as a primary oxidant to initiate DKP-assembly. Single turnover kinetic isotope effects and a substrate analog suggest the probable nature and site for abstraction. The direct observation of CYP-superoxide reactivity rationalizes the atypical outcome of AspB and reveals a new reaction manifold in heme enzymes. DA - 2023/8/23/ PY - 2023/8/23/ DO - 10.1021/jacs.3c04542 VL - 8 SP - SN - 1520-5126 ER - TY - JOUR TI - Repurposing Iron- and 2-Oxoglutarate-Dependent Oxygenases to Catalyze Olefin Hydration AU - Wang, Bingnan AU - Lu, Yong AU - Cha, Lide AU - Chen, Tzu-Yu AU - Palacios, Philip M. AU - Li, Liping AU - Guo, Yisong AU - Chang, Wei-chen AU - Chen, Chuo T2 - ANGEWANDTE CHEMIE-INTERNATIONAL EDITION AB - Mononuclear nonheme iron(II) and 2-oxoglutarate (Fe/2OG)-dependent oxygenases and halogenases are known to catalyze a diverse set of oxidative reactions, including hydroxylation, halogenation, epoxidation, and desaturation in primary metabolism and natural product maturation. However, their use in abiotic transformations has mainly been limited to C-H oxidation. Herein, we show that various enzymes of this family, when reconstituted with Fe(II) or Fe(III), can catalyze Mukaiyama hydration-a redox neutral transformation. Distinct from the native reactions of the Fe/2OG enzymes, wherein oxygen atom transfer (OAT) catalyzed by an iron-oxo species is involved, this nonnative transformation proceeds through a hydrogen atom transfer (HAT) pathway in a 2OG-independent manner. Additionally, in contrast to conventional inorganic catalysts, wherein a dinuclear iron species is responsible for HAT, the Fe/2OG enzymes exploit a mononuclear iron center to support this reaction. Collectively, our work demonstrates that Fe/2OG enzymes have utility in catalysis beyond the current scope of catalytic oxidation. DA - 2023/9/6/ PY - 2023/9/6/ DO - 10.1002/anie.202311099 VL - 9 SP - SN - 1521-3773 KW - Biocatalysis KW - Hydrogen Atom Transfer KW - Mukaiyama Hydration KW - Nonheme Fe/2OG-Dependent Oxygenase ER - TY - JOUR TI - Probing the effect of nitro-substituents in the modulation of LUMO energies for directional electron transport through 4d(6) ruthenium(ii)-based metallosurfactants AU - Amunugama, Samudra AU - Asempa, Eyram AU - Jakubikova, Elena AU - Verani, Claudio N. T2 - DALTON TRANSACTIONS AB - Electron-withdrawing nitro-substituents were installed onto terpyridine- and phenanthroline-based metallosurfactants with 4d6 ruthenium(II), which were deposited as Langmuir-Blodgett monolayers aiming to study the feasibility of charge transport in Au|LB|Au junctions. The nitro groups are intended to modulate the energy of the frontier molecular orbitals to near to, or match that of Fermi levels in the gold electrodes. A series of heteroleptic metallosurfactants [RuII(C18OPh-terpy)(X-terpy)](PF6)2 and [RuII(C18OPh-terpy)(X-phen)Cl]PF6 were synthesized, where C18OPh-terpy is the 4'-[4-(octadecyloxy)phenyl]-2,2':6',2''-terpyridine amphiphile common to all species, X-terpy is a terpyridine with-H (1) or-phenyl-NO2 (2) and X-phen is a phenanthroline with-H (3) or-NO2 (4) groups. These metallosurfactants were characterized by experimental and computational methods, and the presence of nitro groups affect more affordable reductions at less negative potentials, as well as slightly more positive oxidations, these changes are less pronounced in species 2 than in 4. Species 1 and 2 showed limited Pockels-Langmuir and Langmuir-Blodgett film formation with lower collapse pressure of 27 mN m-1. In contrast, metallosurfactants 3 and 4 showed enhanced hydrophilicity indicated by higher collapse pressures of ca. 36 mN m-1. The LB monolayers of 3 and 4 were deposited on gold electrodes to form Au|LB|Au junctions and electron transport was measured as I/V curves. The NO2-bearing species 4 showed asymmetric curves associated with directional electron transport with amplitudes up to -2.0 nA and rectification ratios from 5 to 26 between -1 to +1 V and from 3 to 14 between -3 to +3 V. DA - 2023/8/10/ PY - 2023/8/10/ DO - 10.1039/d3dt01797d VL - 8 SP - SN - 1477-9234 ER - TY - JOUR TI - K2Mn3O(OH)(VO4)(V2O7) with Sawtooth Chains of Multivalent Manganese Triangular Trimer Units: Magnetic Susceptibility Shrouding a Long-Range Antiferromagnetic Order of Ferromagnetic Triangles AU - Yakubovich, Olga V. V. AU - Shvanskaya, Larisa V. V. AU - Kiriukhina, Galina V. V. AU - Simonov, Sergey V. V. AU - Volkov, Anatoly S. S. AU - Dimitrova, Olga V. V. AU - Glazkov, Vasiliy N. N. AU - Ignatenko, Andrey N. N. AU - Chung, Seung Hwan AU - Koo, Hyun-Joo AU - Whangbo, Myung-Hwan AU - Vasiliev, Alexander N. N. T2 - INORGANIC CHEMISTRY AB - ortho-Pyrovanadate (or ortho-diorthovanadate) K2Mn23+Mn2+O(OH)(VO4)(V2O7) synthesized hydrothermally crystallizes in the orthorhombic space group Pnma with a = 17.9155(5), b = 5.8940(2), c = 10.9971(3) Å, V = 1161.23(6) Å3, and Z = 4. Its crystal structure features linear chains of edge-sharing Mn3+O6 octahedra with every second pair of Mn3+O6 octahedra condensed with a Mn2+O6 octahedron on one side of a chain in a sawtooth pattern so that each sawtooth chain consists of a triangular trimer. These sawtooth chains, running parallel to the b axis and linked by the VO4 and V2O7 groups, form a framework with channels populated by K atoms. The new compound is a structural analogue of the mineral zoisite Ca2Al3O(OH)(SiO4)(Si2O7), showing a striking example of very different chemical compositions. K2Mn3O(OH)(VO4)(V2O7) undergoes a phase transition into an ordered antiferromagnetic (AFM) state at TN = 14.4 K, which was detected by high-frequency electron spin resonance as well as by both specific heat Cp and Fisher’s specific heat d(χT)/dT measurements. However, this phase transition was not detected by magnetic susceptibility measurements. The origin of this puzzling observation was resolved by evaluating the spin exchanges of K2Mn3O(OH)(VO4)(V2O7), which revealed that each triangular trimer is a ferromagnetically coupled cluster, and the observed ordering involves an AFM ordering between the ferromagnetic (FM) clusters. This ordering is shrouded in magnetic susceptibility measurements due to the susceptibility contributions from the individual FM triangular trimers even below TN. We showed that the magnetic susceptibility of K2Mn3O(OH)(VO4)(V2O7) between ∼30 K and room temperature is satisfactorily described by an AFM chain made up of ferromagnetically coupled triangular clusters, as described by a few spin-exchange parameters. DA - 2023/8/18/ PY - 2023/8/18/ DO - 10.1021/acs.inorgchem.3c01100 SP - SN - 1520-510X ER - TY - JOUR TI - Metabolite Annotation Confidence Score (MACS): A Novel MSI Identification Scoring Tool AU - Eisenberg, Seth M. AU - Knizner, Kevan T. AU - Muddiman, David C. T2 - JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY AB - Mass spectrometry imaging (MSI) is an analytical technique capable of measuring and visualizing the spatial distribution of thousands of ions across a sample. Measured ions can be putatively identified and annotated by comparing their mass-to-charge ratio (m/z) to a database of known compounds. For high-resolution, accurate mass (HRAM) imaging data sets, this is commonly performed by the annotation platform METASPACE. Annotations are reported with a metabolite-signal-match (MSM) score as a measure of the annotation’s confidence level. However, the MSM scores reported by METASPACE often do not reflect a reasonable confidence level of an annotation and are not assigned consistently. The metabolite annotation confidence score (MACS) is an alternative scoring system based on fundamental mass spectrometry imaging metrics (mass measurement accuracy, spectral accuracy, and spatial distribution) to generate values that reflect the confidence of a specific annotation in HRAM-MSI data sets. Herein, the MACS system is characterized and compared to MSM scores from ions annotated by METASPACE. DA - 2023/8/22/ PY - 2023/8/22/ DO - 10.1021/jasms.3c00178 VL - 8 SP - SN - 1879-1123 KW - IR-MALDESI KW - annotation scoring KW - mass measurementaccuracy KW - spectral accuracy KW - SSIM KW - MATLAB ER - TY - JOUR TI - Bacteriochlorin syntheses - Status, problems, and exploration AU - Tran, Vy-Phuong AU - Wang, Pengzhi AU - Matsumoto, Nobuyuki AU - Liu, Sijia AU - Jing, Haoyu AU - Nalaoh, Phattananawee AU - Nguyen, Khiem Chau AU - Taniguchi, Masahiko AU - Lindsey, Jonathan S. T2 - JOURNAL OF PORPHYRINS AND PHTHALOCYANINES AB - Bacteriochlorins – Nature’s near-infrared (NIR) chromophores – are distinguished by an intense ([Formula: see text] ∼;10 5 M[Formula: see text]cm[Formula: see text] long-wavelength absorption band in the ∼;700–1000 nm. The development of routes to prepare synthetic, tailorable bacteriochlorins holds promise for multiple disciplines where NIR-light-promoted photoactivity is of interest. A de novo route to bacteriochlorins equipped with a stabilizing gem-dimethyl group in each pyrroline ring was discovered in 2003. Continued development in this arena over 20 years has led to additional routes as well as methods to install substituents at selected positions about the perimeter of the macrocycle. The present paper reports studies that highlight substantial limitations of existing synthetic routes, including stymied access to multi-bacteriochlorin arrays and the inability to install (in a rational way) distinct groups at opposite sides of the macrocycle. The origins of the limitations are traced to particular stages of the chemistry ranging from derivatizing pyrroles, creating pyrrolines, constructing and elaborating dihydrodipyrrins, coupling dihydrodipyrrins, and forming macrocycles. Through exploration of a dozen aspects of bacteriochlorin syntheses, 60 new compounds (and nine known compounds via improved syntheses) have been prepared and characterized; the data include 20 single-crystal X-ray diffraction analyses. The research taken together points to areas of focus to fulfill the promise of this fascinating class of compounds. DA - 2023/8/23/ PY - 2023/8/23/ DO - 10.1142/S1088424623501171 VL - 8 SP - SN - 1099-1409 UR - https://doi.org/10.1142/S1088424623501171 KW - bacteriochlorophyll KW - dihydrodipyrrin KW - dyad KW - pyrrole KW - pyrroline KW - near-infrared ER - TY - JOUR TI - Competitive reversed quartet mechanisms for photogenerated ground state electron spin polarization AU - Kirk, Martin L. AU - Shultz, David A. AU - Hewitt, Patrick AU - Marri, Anil Reddy AU - Est, Art T2 - CHEMICAL SCIENCE AB - Photoinduced electron spin polarization (ESP) of a spin-½ organic radical (nitronyl nitroxide, NN) in a series of Pt(ii) complexes comprised of 4,4'-di-tert-butyl-2,2'-bipyridine (bpy) and 3-tert-butylcatecholate (CAT) ligands, where the CAT ligand is substituted with (CH3)n-meta-phenyl-NN (bridge-NN) groups, is presented and discussed. We show the importance of attenuating the energy gap between localized NN radical and chromophoric excited states to control both the magnitude and sign of the optically-generated ESP, and to provide deeper insight into the details of the ESP mechanism. Understanding electronic structure contributions to optically generated ESP will enhance our ability to control the nature of prepared states for a variety of quantum information science applications, where strong ESP facilitates enhanced sensitivity and readout capabilities at low applied magnetic fields and higher temperatures. DA - 2023/9/20/ PY - 2023/9/20/ DO - 10.1039/D3SC03049K VL - 14 IS - 36 SP - 9689-9695 SN - 2041-6539 UR - https://doi.org/10.1039/D3SC03049K ER - TY - JOUR TI - Aggregated Molecular Phenotype Scores: Enhancing Assessment and Visualization of Mass Spectrometry Imaging Data for Tissue-Based Diagnostics AU - Chappel, Jessie R. AU - King, Mary E. AU - Fleming, Jonathon AU - Eberlin, Livia S. AU - Reif, David M. AU - Baker, Erin S. T2 - ANALYTICAL CHEMISTRY AB - Mass spectrometry imaging (MSI) has gained increasing popularity for tissue-based diagnostics due to its ability to identify and visualize molecular characteristics unique to different phenotypes within heterogeneous samples. Data from MSI experiments are often assessed and visualized using various supervised and unsupervised statistical approaches. However, these approaches tend to fall short in identifying and concisely visualizing subtle, phenotype-relevant molecular changes. To address these shortcomings, we developed aggregated molecular phenotype (AMP) scores. AMP scores are generated using an ensemble machine learning approach to first select features differentiating phenotypes, weight the features using logistic regression, and combine the weights and feature abundances. AMP scores are then scaled between 0 and 1, with lower values generally corresponding to class 1 phenotypes (typically control) and higher scores relating to class 2 phenotypes. AMP scores, therefore, allow the evaluation of multiple features simultaneously and showcase the degree to which these features correlate with various phenotypes. Due to the ensembled approach, AMP scores are able to overcome limitations associated with individual models, leading to high diagnostic accuracy and interpretability. Here, AMP score performance was evaluated using metabolomic data collected from desorption electrospray ionization MSI. Initial comparisons of cancerous human tissues to their normal or benign counterparts illustrated that AMP scores distinguished phenotypes with high accuracy, sensitivity, and specificity. Furthermore, when combined with spatial coordinates, AMP scores allow visualization of tissue sections in one map with distinguished phenotypic borders, highlighting their diagnostic utility. DA - 2023/8/14/ PY - 2023/8/14/ DO - 10.1021/acs.analchem.3c02389 VL - 8 SP - SN - 1520-6882 ER - TY - JOUR TI - Late-Stage Chloride Displacements Enable Access to Peptoids with cis-Inducing Alkylammonium Side Chains AU - Davern, Carolynn M. AU - Proulx, Caroline T2 - ORGANIC LETTERS AB - The synthesis of peptoids possessing multiple cis-inducing monomers with alkylammonium side chains is reported, where chloropropyl side chains are diversified on a solid support by late-stage SN2 displacements with amines. The conditions were optimized for a wide variety of primary, secondary, and tertiary alkyl amine nucleophiles. We also demonstrated that multiple chloride displacements could be achieved on sequences possessing trans-inducing N-aryl- and N-imino glycine monomers. DA - 2023/8/14/ PY - 2023/8/14/ DO - 10.1021/acs.orglett.3c02393 VL - 8 SP - SN - 1523-7052 ER - TY - JOUR TI - Comparative study of the binding and activation of 2,4-dichlorophenol by dehaloperoxidase A and B AU - Aktar, Mst Sharmin AU - Serrano, Vesna AU - Ghiladi, Reza AU - Franzen, Stefan T2 - JOURNAL OF INORGANIC BIOCHEMISTRY AB - The dehaloperoxidase-hemoglobin (DHP), first isolated from the coelom of a marine terebellid polychaete, Amphitrite ornata, is an example of a multi-functional heme enzyme. Long known for its reversible oxygen (O2) binding, further studies have established DHP activity as a peroxidase, oxidase, oxygenase, and peroxygenase. The specific reactivity depends on substrate binding at various internal and external binding sites. This study focuses on comparison of the binding and reactivity of the substrate 2,4-dichlorophenol (DCP) in the isoforms DHPA and B. There is strong interest in the degradation of DCP because of its wide use in the chemical industry, presence in waste streams, and particular reactivity to form dioxins, some of the most toxic compounds known. The catalytic efficiency is 3.5 times higher for DCP oxidation in DHPB than DHPA by a peroxidase mechanism. However, DHPA and B both show self-inhibition even at modest concentrations of DCP. This phenomenon is analogous to the self-inhibition of 2,4,6-trichlorophenol (TCP) at higher concentration. The activation energies of the electron transfer steps in DCP in DHPA and DHPB are 19.3 ± 2.5 and 24.3 ± 3.2 kJ/mol, respectively, compared to 37.2 ± 6.5 kJ/mol in horseradish peroxidase (HRP), which may be a result of the more facile electron transfer of an internally bound substrate in DHPA. The x-ray crystal structure of DHPA bound with DCP determined at 1.48 Å resolution, shows tight substrate binding inside the heme pocket of DHPA (PDB 8EJN). This research contributes to the studies of DHP as a naturally occurring bioremediation enzyme capable of oxidizing a wide range of environmental pollutants. DA - 2023/10// PY - 2023/10// DO - 10.1016/j.jinorgbio.2023.112332 VL - 247 SP - SN - 1873-3344 KW - Peroxidase KW - 4-dichlorophenol KW - electron transfer KW - Activation energy KW - Enzyme kinetics KW - Solvent effect ER - TY - JOUR TI - Maximized Spatial Information and Minimized Acquisition Time of Top-Hat IR-MALDESI-MSI of Zebrafish Using Nested Regions of Interest (nROIs) AU - Joignant, Alena N. AU - Ritter, Morgan M. AU - Knizner, Kevan T. AU - Garrard, Kenneth P. AU - Kullman, Seth W. AU - Muddiman, David C. T2 - JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY AB - Increasing the spatial resolution of a mass spectrometry imaging (MSI) method results in a more defined heatmap of the spatial distribution of molecules across a sample, but it is also associated with the disadvantage of increased acquisition time. Decreasing the area of the region of interest to achieve shorter durations results in the loss of potentially valuable information in larger specimens. This work presents a novel MSI method to reduce the time of MSI data acquisition with variable step size imaging: nested regions of interest (nROIs). Using nROIs, a small ROI may be imaged at a higher spatial resolution while nested inside a lower-spatial-resolution peripheral ROI. This conserves the maximal spatial and chemical information generated from target regions while also decreasing the necessary acquisition time. In this work, the nROI method was characterized on mouse liver and applied to top-hat MSI of zebrafish using a novel optical train, which resulted in a significant improvement in both acquisition time and spatial detail of the zebrafish. The nROI method can be employed with any step size pairing and adapted to any method in which the acquisition time of larger high-resolution ROIs poses a practical challenge. DA - 2023/8/1/ PY - 2023/8/1/ DO - 10.1021/jasms.3c00210 VL - 8 SP - SN - 1879-1123 KW - IR-MALDESI KW - mass spectrometry imaging KW - spatialresolution KW - nested region of interest KW - zebrafish ER - TY - JOUR TI - Absorption and fluorescence spectra of open-chain tetrapyrrole pigments-bilirubins, biliverdins, phycobilins, and synthetic analogues AU - Taniguchi, Masahiko AU - Lindsey, Jonathan S. T2 - JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS AB - Open-chain tetrapyrroles are ubiquitous and abundant in living organisms (algae, animals, bacteria, and plants), including examples such as bilirubin, biliverdin, phycocyanobilin, phycoerythrobilin, and urobilin. The open-chain tetrapyrroles, collectively termed bilins, arise from biosynthesis or degradation of tetrapyrrole macrocycles. Bilins are now known to play a wide variety of biological roles encompassing light-harvesting (in phycobiliproteins), photomorphogenesis, signaling, and redox chemistry. The absorption spectra of bilins spans the ultraviolet (UV), visible, to near-infrared (NIR) regions depending on the degree of conjugation, thereby providing a wide range of colors from red/orange to blue/green. The fluorescence intensity of bilins is often quite low and hence fewer spectra are available, but can be increased substantially by structural rigidification, as evidenced by the wide use of biliproteins as fluorescent labels. The present article describes a database of absorption and fluorescence spectra of bilins from natural and synthetic origins for 220 compounds (270 absorption and 13 fluorescence spectral traces). Spectral traces of bilins published over the past ∼50 years have been digitized and assembled along with information concerning solvent, photochemical properties (molar absorption coefficient and fluorescence quantum yield), and literature references. The spectral traces (xy-coordinate data files) can be viewed, downloaded, and accessed at www.photochemcad.com. The accessibility of spectral traces in digital format should facilitate identification and quantitative calculations of interest in diverse scientific areas. DA - 2023/6// PY - 2023/6// DO - 10.1016/j.jphotochemrev.2023.100585 VL - 55 SP - SN - 1873-2739 KW - Bile pigment KW - Bilin KW - Biliprotein KW - Luciferin KW - Phycobilin KW - Phyllobilin KW - Phytochrome ER - TY - JOUR TI - Water under the influence of solutes: On the non-innocence of a universal solvent AU - Martin, James D. T2 - MATTER AB - Water interactions with materials can dramatically change their properties, but the solute material also changes the properties of water. Here, a Solvation Shell-Liquid Solvate (SSLS) model is presented that provides a molecular-based description of water interacting with sucrose and cellulose for which multiple types of water are identified. Bound water most significantly changes the specific material’s properties, whereas the hard-to-remove water, i.e., water that is significantly modified by the influence of the solute, is responsible for bulk properties such as the system’s liquidus. Both types of water are significantly distinct from classical descriptions that treat solvents as an inert medium. This model provides the molecular basis for the insights into the molecular architecture of water-cellulose networks described in this issue of Matter and further provides a framework that can generally be applied to diverse aqueous systems. Water interactions with materials can dramatically change their properties, but the solute material also changes the properties of water. Here, a Solvation Shell-Liquid Solvate (SSLS) model is presented that provides a molecular-based description of water interacting with sucrose and cellulose for which multiple types of water are identified. Bound water most significantly changes the specific material’s properties, whereas the hard-to-remove water, i.e., water that is significantly modified by the influence of the solute, is responsible for bulk properties such as the system’s liquidus. Both types of water are significantly distinct from classical descriptions that treat solvents as an inert medium. This model provides the molecular basis for the insights into the molecular architecture of water-cellulose networks described in this issue of Matter and further provides a framework that can generally be applied to diverse aqueous systems. Computational and experimental insights into the molecular architecture of water-cellulose networksSalem et al.MatterMay 03, 2023In BriefA depiction of water-cellulose interactions as leveraged by hydroxyls is represented that govern “stacking” upon which subsequent chemical reactivity and physical properties are predicated. The nature of water states within stacking (e.g., one state is HR = hard-to-remove) dictates non-intuitive reactivity but can be invoked and applied to explain and control observables for cellulosic-based paper properties. For example, cellulosic fiber collapse from water removal is dependent on the quantity of HR states of water within the cellulose polymer units of the fiber. Full-Text PDF DA - 2023/5/3/ PY - 2023/5/3/ DO - 10.1016/j.matt.2023.03.020 VL - 6 IS - 5 SP - 1316-1319 SN - 2590-2385 ER - TY - JOUR TI - Exploiting Microelectrode Geometry for Comprehensive Detection of Individual Exocytosis Events at Single Cells AU - De Alwis, A. Chathuri AU - Denison, J. Dylan AU - Shah, Ruby AU - McCarty, Gregory S. AU - Sombers, Leslie A. T2 - ACS SENSORS AB - Carbon fiber microelectrodes are commonly used for real-time monitoring of individual exocytosis events at single cells. Since the nature of an electrochemical signal is fundamentally governed by mass transport to the electrode surface, microelectrode geometry can be exploited to achieve precise and accurate measurements. Researchers traditionally pair amperometric measurements of exocytosis with a ∼10-μm diameter, disk microelectrode in an "artificial synapse" configuration to directly monitor individual release events from single cells. Exocytosis is triggered, and released molecules diffuse to the "post-synaptic" electrode for oxidation. This results in a series of distinct current spikes corresponding to individual exocytosis events. However, it remains unclear how much of the material escapes detection. In this work, the performance of 10- and 34-μm diameter carbon fiber disk microelectrodes was directly compared in monitoring exocytosis at single chromaffin cells. The 34-μm diameter electrode was more sensitive to catecholamines and enkephalins than its traditional, 10-μm diameter counterpart, and it more effectively covered the entire cell. As such, the larger sensor detected more exocytosis events overall, as well as a larger quantal size, suggesting that the traditional tools underestimate the above measurements. Both sensors reliably measured l-DOPA-evoked changes in quantal size, and both exhibited diffusional loss upon adjustment of cell-electrode spacing. Finite element simulations using COMSOL support the improved collection efficiency observed using the larger sensor. Overall, this work demonstrates how electrode geometry can be exploited for improved detection of exocytosis events by addressing diffusional loss─an often-overlooked source of inaccuracy in single-cell measurements. DA - 2023/8/8/ PY - 2023/8/8/ DO - 10.1021/acssensors.3c00884 VL - 8 SP - SN - 2379-3694 KW - voltammetry KW - amperometry KW - chromaffincell KW - diffusion KW - catecholamine KW - dense corevesicle KW - carbon fiber microelectrode ER - TY - JOUR TI - Exploring synchrony and chaos of parahydrogen-pumped two-compartment radio-frequency amplification by stimulated emission of radiation AU - Lohmann, Lars AU - Lehmkuhl, Soeren AU - Fleischer, Simon AU - Rosen, Matthew S. AU - Chekmenev, Eduard Y. AU - Theis, Thomas AU - Adams, Alina AU - Appelt, Stephan T2 - PHYSICAL REVIEW A AB - A nuclear-spin-based RASER (radio-frequency amplification by stimulated emission of radiation) is an ideal experimental system to explore nonlinear interaction phenomena of nuclear spins coupled via virtual photons to a resonator. This is due to the RASER being stable for several hours, allowing for extended observation of these phenomena. Nonlinear phenomena in multimode RASERs range from mode oscillations in synchrony, frequency shifts, frequency combs, period doublings, and even chaos. These phenomena are observed in a parahydrogen-pumped two-compartment proton RASER. In two independently pumped compartments, the separation in frequency space between the two RASER modes is precisely controlled with a magnetic field gradient. By controlling the mode separation, we can select the type of nonlinear phenomena observed. A key finding is that the ranges of mode separation where chaos and synchrony occur are very close together. The experimental results are supported by numerical simulations, based on two-mode RASER equations. DA - 2023/8/15/ PY - 2023/8/15/ DO - 10.1103/PhysRevA.108.022806 VL - 108 IS - 2 SP - SN - 2469-9934 UR - https://doi.org/10.1103/PhysRevA.108.022806 ER - TY - JOUR TI - Ethanol Upgrading to n-Butanol Using Transition-Metal-Incorporated Poly(triazine)imide Frameworks AU - Cypher, Sabrine M. AU - Pauly, Magnus AU - Castro, Leslie G. AU - Donley, Carrie L. AU - Maggard, Paul A. AU - Goldberg, Karen I. T2 - ACS APPLIED MATERIALS & INTERFACES AB - The upgrading of ethanol to n-butanol was performed using a molecular catalyst integrated into a carbon nitride support, one of the first examples of a supported molecular catalyst performing the Guerbet process. Initial studies using crystalline poly(triazine)imide (PTI) with lithium or transition-metal cations imbedded in the support together with a base as the catalyst system did not produce any significant amounts of n-butanol. However, when using the catalyst material formed by treatment of PTI-LiCl with [(Cp*)IrCl2]2 (Cp* = pentamethylcyclopentadienyl) along with sodium hydroxide, a 59% selectivity for butanol (13% yield) was obtained at 145 °C. This PTI-(Cp*)Ir material exhibited distinct UV-vis absorption features and powder X-ray diffractions which differ from those of the parent PTI-LiCl and [(Cp*)IrCl2]2. The PTI-(Cp*)Ir material was found to have a metal loading of 27% iridium per empirical unit of the framework. Along with the formation of n-butanol from the Guerbet reaction, the presence of higher chain alcohols was also observed. DA - 2023/7/24/ PY - 2023/7/24/ DO - 10.1021/acsami.3c07396 VL - 15 IS - 30 SP - 36384-36393 SN - 1944-8252 KW - catalysis KW - Guerbet KW - ethanol KW - butanol KW - carbon nitride KW - supported catalysts ER - TY - JOUR TI - Tuning the Surface Energy of Hole Transport Layers Based on Carbazole Self-Assembled Monolayers for Highly Efficient Sn/Pb Perovskite Solar Cells AU - Pitaro, Matteo AU - Alonso, Javier E. Sebastian AU - Di Mario, Lorenzo AU - Romero, David Garcia AU - Tran, Karolina AU - Kardula, Jane AU - Zaharia, Teodor AU - Johansson, Malin B. AU - Johansson, Erik M. J. AU - Chiechi, Ryan C. AU - Loi, Maria A. T2 - ADVANCED FUNCTIONAL MATERIALS AB - Abstract Recently, carbazole‐based self‐assembled monolayers (SAMs) have been utilized as hole transport layers (HTLs) in perovskite solar cells. However, their application in Sn or mixed Sn/Pb perovskite solar cells has been hindered by the poor wettability of the perovskite precursor solution on the carbazole surface. Here a self‐assembled bilayer (SAB) comprising a covalent monolayer (Br‐2PACz) and a noncovalent wetting layer (4CzNH 3 I) as the HTL in a Cs 0.25 FA 0.75 Sn 0.5 Pb 0.5 I 3 perovskite solar cell is proposed. It is demonstrated that the wetting layer completely solves the problem due to the higher polarity of the surface and, furthermore, the ammonium groups help in the passivation of trap states at the buried SAB/perovskite interface. The introduction of the SAB enhances the device reproducibility with an average efficiency of 18.98 ± 0.28% (19.45% for the best device), compared to 11.54 ± 9.36% (19.34% for the best device) for the SAM‐only devices. Furthermore, the improved perovskite processability on the SAB helps to increase the reproducibility of larger size device, where, a 12.5% efficiency for a 0.8 cm 2 active area device compared to 0.68% for the best SAM‐based solar cell is demonstrated. Finally, the device's operational stability is also improved to 358 hours (T 80% ), compared to 220 hours for the SAM‐based solar cell. DA - 2023/8/13/ PY - 2023/8/13/ DO - 10.1002/adfm.202306571 VL - 8 SP - SN - 1616-3028 UR - https://doi.org/10.1002/adfm.202306571 KW - carbazole-based SAMs KW - mixed Sn KW - Pb perovskites KW - perovskite solar cells KW - scalability KW - stability KW - wettability problem ER - TY - JOUR TI - Using Stem Mini-Organs to Find New Cures AU - Piedrahita, Jorge AU - Pierce, Joshua DA - 2023/8/4/ PY - 2023/8/4/ DO - 10.52750/572466 UR - https://doi.org/10.52750/572466 ER - TY - JOUR TI - Synthesis of a BC-Dihydrodipyrrin Building Block of Bacteriochlorophyll a AU - Nguyen, Khiem Chau AU - Lindsey, Jonathan S. T2 - JOURNAL OF ORGANIC CHEMISTRY AB - A strategy for the synthesis of bacteriochlorophyll a relies on joining AD and BC halves that contain the requisite stereochemical configurations of the target macrocycle. The BC half (1) is a dihydrodipyrrin bearing a dimethoxymethyl group at the 1-position, a β-ketoester at the 8-position, and (R)-2-methyl and (R)-3-ethyl substituents in the pyrroline ring. An established route to AD-dihydrodipyrrins (Pd-mediated coupling of a 2-halopyrrole with a chiral 4-pentynoic acid followed by Petasis methenylation, acidic hydrolysis, Paal–Knorr ring closure, and Riley oxidation) proved to be unviable for BC-dihydrodipyrrins given the presence of the β-ketoester unit. A route presented here entails Pd-mediated coupling of a 2-halopyrrole (2) with (3R,4R)-4-ethyl-1,1-dimethoxy-3-methylhex-5-yn-2-one (3), anti-Markovnikov hydration of the alkyne to give the 1,4-diketone, and Paal–Knorr ring closure. Compound 3 was prepared by Schreiber-modified Nicholas reaction beginning with (S)-4-isopropyl-3-propionyloxazolidin-2-one and the hexacarbonyldicobalt complex of (±) 3-methoxy-1-(trimethylsilyl)pentyne followed by transformation of the aldehyde derived therefrom to the 1,1-dimethoxymethylcarbonyl motif. The absolute stereochemical configuration of the Schreiber–Nicholas alkylation product was confirmed by single-crystal X-ray diffraction, whereas the BC half (1) by 1H NMR spectroscopy showed a J value of 2.9 Hz consistent with the trans-configuration. Taken together, the route provides a key chiral building block for the synthesis of photosynthetic tetrapyrroles and analogues. DA - 2023/7/20/ PY - 2023/7/20/ DO - 10.1021/acs.joc.3c01216 VL - 7 SP - SN - 1520-6904 UR - https://doi.org/10.1021/acs.joc.3c01216 ER - TY - JOUR TI - Enhanced Detection of Charged N-Glycans in the Brain by Infrared Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometric Imaging AU - Samal, Juhi AU - Palomino, Tana V. AU - Chen, Judy AU - Muddiman, David C. AU - Segura, Tatiana T2 - ANALYTICAL CHEMISTRY AB - N-linked glycosylation represents a structurally diverse, complex, co- and posttranslational protein modification that bridges metabolism and cellular signaling. Consequently, aberrant protein glycosylation is a hallmark of most pathological scenarios. Due to their complex nature and non-template-driven synthesis, the analysis of glycans is faced with several challenges, underlining the need for new and improved analytical technologies. Spatial profiling of N-glycans through direct imaging on tissue sections reveals the regio-specific and/or disease pathology correlating tissue N-glycans that serve as a disease glycoprint for diagnosis. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) is a soft hybrid ionization technique that has been used for diverse mass spectrometry imaging (MSI) applications. Here, we report the first spatial analysis of the brain N-linked glycans by IR-MALDESI MSI, leading to a significant increase in the detection of the brain N-sialoglycans. A formalin-fixed paraffin-embedded mouse brain tissue was analyzed in negative ionization mode after tissue washing, antigen retrieval, and pneumatic application of PNGase F for enzymatic digestion of N-linked glycans. We report a comparative analysis of section thickness on the N-glycan detection using IR-MALDESI. One hundred thirty-six unique N-linked glycans were confidently identified in the brain tissue (with an additional 132 unique N-glycans, not reported in GlyConnect), where more than 50% contained sialic acid residues, which is approximately 3-fold higher than the previous reports. This work demonstrates the first application of IR-MALDESI in N-linked glycan imaging of the brain tissue, leading to a 2.5-fold increase in the in situ total brain N-glycan detection compared to the current gold standard of positive-mode matrix-assisted laser desorption/ionization mass spectrometry imaging. This is also the first report of the application of the MSI toward the identification of sulfoglycans in the rodent brain. Overall, IR-MALDESI-MSI presents a sensitive glycan detection platform to identify tissue-specific and/or disease-specific glycosignature in the brain while preserving the sialoglycans without any chemical derivatization. DA - 2023/7/10/ PY - 2023/7/10/ DO - 10.1021/acs.analchem.3c00494 VL - 95 IS - 29 SP - 10913-10920 SN - 1520-6882 ER - TY - JOUR TI - Divergent Synthesis of & beta;-Fluoroamides via Silver-Catalyzed Oxidative Deconstruction of Cyclopropanone Hemiaminals AU - Jang, Yujin AU - Deng, Weixia AU - Sprague, Ivan S. S. AU - Lindsay, Vincent N. G. T2 - ORGANIC LETTERS AB - An expedient approach for the synthesis of challenging β-fluoroamides from readily accessible cyclopropanone equivalents is reported. Following the addition of pyrazole used here as a transient leaving group, silver-catalyzed regiospecific ring-opening fluorination of the resulting hemiaminal leads to a β-fluorinated N-acylpyrazole intermediate reactive to substitution with amines, ultimately affording β-fluoroamides. The process could also be extended to the synthesis of β-fluoroesters and γ-fluoroalcohols via the addition of alcohols or hydrides as terminal nucleophiles, respectively. DA - 2023/7/6/ PY - 2023/7/6/ DO - 10.1021/acs.orglett.3c01992 VL - 7 SP - SN - 1523-7052 UR - https://doi.org/10.1021/acs.orglett.3c01992 ER - TY - JOUR TI - A Student Perspective on the 18th Monitoring Molecules in Neuroscience Meeting in Lyon AU - Forderhase, Alexandra G. AU - Kimble, Laney C. AU - Sombers, Leslie A. T2 - ACS CHEMICAL NEUROSCIENCE AB - After being postponed twice due to the global COVID-19 pandemic, approximately 200 scientists gathered in Lyon, France, in late June 2022 for the 18th Biennial Monitoring Molecules in Neuroscience (MMiN) Research Conference. Although there were unprecedented challenges involved with coordinating the 18th MMiN conference, the meeting was a huge success. The meeting provided a wonderful opportunity for young neuroscientists to network and learn about the current state of molecular monitoring in neuroscience research. The topics spanned advancements in well-established analytical techniques to novel method development. Some of the noteworthy techniques expediting our understanding of circuit-level neurochemical function include multiplexed detection of numerous neurochemicals, well-established sensors leveraging enzymes and other biologic components, and the development of diverse, customizable genetically encoded sensors. DA - 2023/6/5/ PY - 2023/6/5/ DO - 10.1021/acschemneuro.3c00271 VL - 6 SP - SN - 1948-7193 KW - Biosensors KW - multiplexing KW - genetically encodedsensors KW - in vivo KW - neurochemistry KW - analyticalmethods ER - TY - JOUR TI - Spin-vibronic coherence drives singlet-triplet conversion AU - Rafiq, Shahnawaz AU - Weingartz, Nicholas P. AU - Kromer, Sarah AU - Castellano, Felix N. AU - Chen, Lin X. T2 - NATURE DA - 2023/7/19/ PY - 2023/7/19/ DO - 10.1038/s41586-023-06233-y VL - 7 SP - SN - 1476-4687 UR - https://doi.org/10.1038/s41586-023-06233-y ER - TY - JOUR TI - Comparison of Aptamer Signaling Mechanisms Reveals Disparities in Sensor Response and Strategies to Eliminate False Signals AU - Alkhamis, Obtin AU - Canoura, Juan AU - Willis, Connor AU - Wang, Linlin AU - Perry, Jacob AU - Xiao, Yi T2 - JOURNAL OF THE AMERICAN CHEMICAL SOCIETY AB - Aptamers are nucleic acid-based affinity reagents that have been incorporated into a variety of molecular sensor formats. However, many aptamer sensors exhibit insufficient sensitivity and specificity for real-world applications, and although considerable effort has been dedicated to improving sensitivity, sensor specificity has remained largely neglected and understudied. In this work, we have developed a series of sensors using aptamers for the small-molecule drugs flunixin, fentanyl, and furanyl fentanyl and compare their performance─in particular, focusing on their specificity. Contrary to expectations, we observe that sensors using the same aptamer operating under the same physicochemical conditions produce divergent responses to interferents depending on their signal transduction mechanism. For instance, aptamer beacon sensors are susceptible to false-positives from interferents that weakly associate with DNA, while strand-displacement sensors suffer from false-negatives due to interferent-associated signal suppression when both the target and interferent are present. Biophysical analyses suggest that these effects arise from aptamer-interferent interactions that are either nonspecific or induce aptamer conformational changes that are distinct from those induced by true target-binding events. We also demonstrate strategies for improving the sensitivity and specificity of aptamer sensors with the development of a "hybrid beacon," wherein the incorporation of a complementary DNA competitor into an aptamer beacon selectively hinders interferent─but not target─binding and signaling, while simultaneously overcoming signal suppression by interferents. Our results highlight the need for systematic and thorough testing of aptamer sensor response and new aptamer selection methods that optimize specificity more effectively than traditional counter-SELEX. DA - 2023/5/22/ PY - 2023/5/22/ DO - 10.1021/jacs.3c03640 VL - 145 IS - 22 SP - 12407-12422 SN - 1520-5126 ER - TY - JOUR TI - A cascade of magnetic phase transitions and a 1/3-magnetization plateau in selenite-selenate Co-3(SeO3)(SeO4)(OH)(2) with kagome-like Co2+ ion layer arrangements: the importance of identifying a correct spin lattice AU - Murtazoev, A. F. AU - Berdonosov, P. S. AU - Lyssenko, K. A. AU - Dolgikh, V. A. AU - Geidorf, M. Y. AU - Volkova, O. S. AU - Koo, H. -J AU - Whangbo, M. -H AU - Vasiliev, A. N. T2 - DALTON TRANSACTIONS AB - Co 3 (SeO 3 )(SeO 4 )(OH) 2 has kagomé-like layers of Co 2+ ions. It undergoes magnetic transitions at 27.5, 19.4 and 8.1 K, and exhibits a 1/3-magnetization plateau. The H – T diagram shows an antiferromagnetic phase I and ferrimagnetic phases II and III. DA - 2023/6/15/ PY - 2023/6/15/ DO - 10.1039/d3dt01620j SP - SN - 1477-9234 ER - TY - JOUR TI - Synthesis of model southern rim structures of photosynthetic tetrapyrroles and phyllobilins AU - Nguyen Tran, Anh Thu AU - Wu, Zhiyuan AU - Chung, Duy T. M. AU - Nalaoh, Phattananawee AU - Lindsey, Jonathan S. T2 - NEW JOURNAL OF CHEMISTRY AB - Two simple pyrroles react in two simple reactions to afford a dipyrromethane analogue of the southern rim of native tetrapyrroles and their catabolites. DA - 2023/7/5/ PY - 2023/7/5/ DO - 10.1039/d3nj02515b VL - 7 SP - SN - 1369-9261 UR - http://dx.doi.org/10.1039/d3nj02515b ER - TY - JOUR TI - Dark matter: Developing a new nanoantioxidant-based therapeutic system for the treatment of age-related macular degeneration AU - Kwon, Yong-Su AU - Voinov, Maxim A. AU - Zheng, Min AU - Smirnov, Alex I. AU - Han, Zongchao T2 - NANO TODAY AB - Excessive production of reactive oxygen and nitrogen species (RONS) leads to nonspecific inflammation and is a major cause of the pathogenesis of exudative and nonexudative forms of age-related macular degeneration (AMD). As a result, antioxidant therapy has been emerging as a promising means for the treatment and prevention of AMD. Nevertheless, antioxidant strategies have largely been unsuccessful for AMD treatment. Developing a more potent antioxidant that reaches its target, remains stable with specific RONS level regulation, and reduces treatment burdens would provide a foundation for the care and scientific understanding of using antioxidant therapies in AMD. To overcome these limitations, we developed a novel robust nanotechnology-mediated antioxidant strategy based on ceria-coated melanin-PEG nanoparticles (CMNPs) by taking advantage of their inherent antioxidant ability to autorenew cerium oxide nanoparticles (ceria) and their photoprotective role through scavenging a broad range of RONS of melanin. Our experiments demonstrate that CMNPs could relieve AMD-like pathology with long-term improvement and exhibited a significant synergistic effect in scavenging against multiple RONS compared to single-nanoantioxidant delivery. More importantly, CMNPs ensured autoregenerative properties, outperformed aflibercept, and relieved pathological damage in an AMD-like mouse model through a single-dose administration for up to three months. This study highlights a novel treatment targeted to preserve the RPE and photoreceptors in AMD as a monotherapy. DA - 2023/6// PY - 2023/6// DO - 10.1016/j.nantod.2023.101879 VL - 50 SP - SN - 1878-044X KW - Age-related macular degeneration KW - Cerium oxide nanoparticles KW - Melanin-like nanoparticles KW - Antioxidant KW - Reactive oxygen and nitrogen species KW - Laser-induced choroidal neovascularization ER - TY - JOUR TI - C-13 Radiofrequency Amplification by Stimulated Emission of Radiation Threshold Sensing of Chemical Reactions AU - Schmidt, Andreas B. AU - Adelabu, Isaiah AU - Nelson, Christopher AU - Nantogma, Shiraz AU - Kiselev, Valerij G. AU - Zaitsev, Maxim AU - Abdurraheem, Abubakar AU - Maissin, Henri AU - Rosen, Matthew S. AU - Lehmkuhl, Soren AU - Appelt, Stephan AU - Theis, Thomas AU - Chekmenev, Eduard Y. T2 - JOURNAL OF THE AMERICAN CHEMICAL SOCIETY AB - Conventional nuclear magnetic resonance (NMR) enables detection of chemicals and their transformations by exciting nuclear spin ensembles with a radio-frequency pulse followed by detection of the precessing spins at their characteristic frequencies. The detected frequencies report on chemical reactions in real time and the signal amplitudes scale with concentrations of products and reactants. Here, we employ Radiofrequency Amplification by Stimulated Emission of Radiation (RASER), a quantum phenomenon producing coherent emission of 13C signals, to detect chemical transformations. The 13C signals are emitted by the negatively hyperpolarized biomolecules without external radio frequency pulses and without any background signal from other, nonhyperpolarized spins in the ensemble. Here, we studied the hydrolysis of hyperpolarized ethyl-[1-13C]acetate to hyperpolarized [1-13C]acetate, which was analyzed as a model system by conventional NMR and 13C RASER. The chemical transformation of 13C RASER-active species leads to complete and abrupt disappearance of reactant signals and delayed, abrupt reappearance of a frequency-shifted RASER signal without destroying 13C polarization. The experimentally observed "quantum" RASER threshold is supported by simulations. DA - 2023/5/12/ PY - 2023/5/12/ DO - 10.1021/jacs.3c00776 VL - 145 IS - 20 SP - 11121-11129 SN - 1520-5126 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85160017400&partnerID=MN8TOARS ER - TY - JOUR TI - Successive short- and long-range magnetic ordering in rosiaite-type CoGeTeO6 prepared by ion-exchange reaction AU - Bazhan, Roman V. AU - Nalbandyan, Vladimir B. AU - Vasilchikova, Tatyana M. AU - Koo, Hyun-Joo AU - Whangbo, Myung-Hwan AU - Vasiliev, Alexander N. T2 - DALTON TRANSACTIONS AB - CoGeTeO 6 , the missing member of the rosiaite family, was obtained from Na 2 GeTeO 6 by ion-exchange reaction. It undergoes short- and long-range magnetic ordering well separated with respect to temperature due to the spin frustration. DA - 2023/6/14/ PY - 2023/6/14/ DO - 10.1039/d3dt01164j SP - SN - 1477-9234 ER - TY - JOUR TI - Electronic Structures and Photoredox Chemistry of Tungsten(0) Arylisocyanides AU - Barth, Alexandra T. AU - Fajardo Jr, Javier AU - Sattler, Wesley AU - Winkler, Jay R. AU - Gray, Harry B. T2 - ACCOUNTS OF CHEMICAL RESEARCH AB - ConspectusThe high energy barriers associated with the reaction chemistry of inert substrates can be overcome by employing redox-active photocatalysts. Research in this area has grown exponentially over the past decade, as transition metal photosensitizers have been shown to mediate challenging organic transformations. Critical for the advancement of photoredox catalysis is the discovery, development, and study of complexes based on earth-abundant metals that can replace and/or complement established noble-metal-based photosensitizers.Recent work has focused on redox-active complexes of 3d metals, as photosensitizers containing these metals most likely would be scalable. Although low lying spin doublet ("spin flip") excited states of chromium(III) and metal-to-ligand charge transfer (MLCT) excited states of copper(I) have relatively long lifetimes, the electronic excited states of many other 3d metal complexes fall on dissociative potential energy surfaces, owing to the population of highly energetic σ-antibonding orbitals. Indeed, we and other investigators have shown that low lying spin singlet and triplet excited states of robust closed-shell metal complexes are too short-lived at room temperature to engage in bimolecular reactions in solutions. In principle, this problem could be overcome by designing and constructing 3d metal complexes containing strong field π-acceptor ligands, where thermally equilibrated MLCT or intraligand charge transfer excited states might fall well below the upper surfaces of dissociative 3d-3d states. Notably, such design elements have been exploited by investigators in very recent work on redox-active iron(II) systems. Another approach, one we have actively pursued, is to design and construct closed-shell complexes of earth-abundant 5d metals containing very strong π-acceptor ligands, where vertical excitation of 5d-5d excited states at the ground state geometry would require energies far above minima in the potential surfaces of MLCT excited states. As this requirement is met by tungsten(0) arylisocyanides, these complexes have been the focus of our work aimed at the development of robust redox-active photosensitizers.In the following Account, we review recent work on homoleptic tungsten(0) arylisocyanides. Originally reported by our group 45 years ago, W(CNAr)6 complexes have exceptionally large one- and two-photon absorption cross-sections. One- or two-photon excitation produces relatively long-lived (hundreds of nanoseconds to microsecond) MLCT excited states in high yields. These MLCT excited states, which are very strong reductants with E°(W+/*W0) = -2.2 to -3.0 V vs Fc[+/0], mediate photocatalysis of organic reactions with both visible and near-infrared (NIR) light. Here, we highlight design principles that led to the development of three generations of W(CNAr)6 photosensitizers; and we discuss likely steps in the mechanism of a prototypal W(CNAr)6-catalyzed base-promoted homolytic aromatic substitution reaction. Among the many potential applications of these very bright luminophores, two-photon imaging and two-photon-initiated polymerization are ones we plan to pursue. DA - 2023/6/29/ PY - 2023/6/29/ DO - 10.1021/acs.accounts.3c00184 SP - SN - 1520-4898 ER - TY - JOUR TI - Integrative Chemical–Biological Grouping of Complex High Production Volume Substances from Lower Olefin Manufacturing Streams AU - Cordova, Alexandra C. AU - Klaren, William D. AU - Ford, Lucie C. AU - Grimm, Fabian A. AU - Baker, Erin AU - Zhou, Yi-Hui AU - Wright, Fred A. AU - Rusyn, Ivan T2 - Toxics AB - Human cell-based test methods can be used to evaluate potential hazards of mixtures and products of petroleum refining (“unknown or variable composition, complex reaction products, or biological materials” substances, UVCBs). Analyses of bioactivity and detailed chemical characterization of petroleum UVCBs were used separately for grouping these substances; a combination of the approaches has not been undertaken. Therefore, we used a case example of representative high production volume categories of petroleum UVCBs, 25 lower olefin substances from low benzene naphtha and resin oils categories, to determine whether existing manufacturing-based category grouping can be supported. We collected two types of data: nontarget ion mobility spectrometry-mass spectrometry of both neat substances and their organic extracts and in vitro bioactivity of the organic extracts in five human cell types: umbilical vein endothelial cells and induced pluripotent stem cell-derived hepatocytes, endothelial cells, neurons, and cardiomyocytes. We found that while similarity in composition and bioactivity can be observed for some substances, existing categories are largely heterogeneous. Strong relationships between composition and bioactivity were observed, and individual constituents that determine these associations were identified. Overall, this study showed a promising approach that combines chemical composition and bioactivity data to better characterize the variability within manufacturing categories of petroleum UVCBs. DA - 2023/7// PY - 2023/7// DO - 10.3390/toxics11070586 UR - https://www.mdpi.com/2305-6304/11/7/586 ER - TY - JOUR TI - Predicting properties of high entropy carbides from their respective binaries AU - Lim, Mina AU - Brenner, Donald W. T2 - COMPUTATIONAL MATERIALS SCIENCE AB - Using Density Functional Theory calculations, this paper addresses two questions: (1) to what degree can the properties of high entropy carbides created by equi-molar combinations of five of the set of eight refractory metals Hf, Nb, Mo, Ta, Ti, V, W, and Zr be predicted from their respective binary compounds, and (2) can empirical relationships from properties of the binary compounds be used to predict phase stability for these materials. For the former question, it is found that lattice constant, binding energy and bulk modulus are well approximated by binary carbide averages, but carbon vacancy formation energies are less predictable. To address the second question, correlations are explored between binary properties and the entropy forming ability (EFA) of all 56 possible five-element combinations of the eight refractory elements. Significant correlations are not found between cohesive energies or lattice constants of the binary constituents of each composition and that composition’s EFA, but there is a correlation between EFA and the standard deviation of the distribution of bulk moduli of the constituent binaries. DA - 2023/6/25/ PY - 2023/6/25/ DO - 10.1016/j.commatsci.2023.112255 VL - 226 SP - SN - 1879-0801 KW - Density Functional Theory (DFT) KW - Entropy Forming Ability (EFA) KW - and High Entropy Carbides (HECs) ER - TY - JOUR TI - Development of an object-based image analysis tool for mass spectrometry imaging ion classification AU - Eisenberg, Seth M. AU - Knizner, Kevan T. AU - Muddiman, David C. T2 - ANALYTICAL AND BIOANALYTICAL CHEMISTRY DA - 2023/5/24/ PY - 2023/5/24/ DO - 10.1007/s00216-023-04764-x VL - 5 SP - SN - 1618-2650 KW - IR-MALDESI KW - Object-based image analysis KW - Mass spectrometry imaging KW - Image segmentation KW - Image classification KW - MATLAB ER - TY - JOUR TI - Effect of Electrode/Electrolyte Coupling on Birnessite (delta-MnO2) Mechanical Response and Degradation AU - Tsai, Wan-Yu AU - Pillai, Shelby B. B. AU - Ganeshan, Karthik AU - Saeed, Saeed AU - Gao, Yawei AU - Duin, Adri C. T. AU - Augustyn, Veronica AU - Balke, Nina T2 - ACS APPLIED MATERIALS & INTERFACES AB - Understanding the deformation of energy storage electrodes at a local scale and its correlation to electrochemical performance is crucial for designing effective electrode architectures. In this work, the effect of electrolyte cation and electrode morphology on birnessite (δ-MnO2) deformation during charge storage in aqueous electrolytes was investigated using a mechanical cyclic voltammetry approach via operando atomic force microscopy (AFM) and molecular dynamics (MD) simulation. In both K2SO4 and Li2SO4 electrolytes, the δ-MnO2 host electrode underwent expansion during cation intercalation, but with different potential dependencies. When intercalating Li+, the δ-MnO2 electrode presents a nonlinear correlation between electrode deformation and electrode height, which is morphologically dependent. These results suggest that the stronger cation-birnessite interaction is the reason for higher local stress heterogeneity when cycling in Li2SO4 electrolyte, which might be the origin of the pronounced electrode degradation in this electrolyte. DA - 2023/5/18/ PY - 2023/5/18/ DO - 10.1021/acsami.3c02055 VL - 15 IS - 21 SP - 26120-26127 SN - 1944-8252 KW - Operando AFM KW - Mechanical cyclic voltammetry KW - Electrode microstructure KW - Electro-chemo-mechanical coupling KW - Pseudocapacitors ER - TY - JOUR TI - Article Tethered Indoxyl-Glucuronides for Enzymatically Triggered Cross-Linking AU - Son, Juno AU - Wu, Zhiyuan AU - Dou, Jinghuai AU - Fujita, Hikaru AU - Cao, Phuong-Lien Doan AU - Liu, Qihui AU - Lindsey, Jonathan S. T2 - MOLECULES AB - Indoxyl-glucuronides, upon treatment with β-glucuronidase under physiological conditions, are well known to afford the corresponding indigoid dye via oxidative dimerization. Here, seven indoxyl-glucuronide target compounds have been prepared along with 22 intermediates. Of the target compounds, four contain a conjugatable handle (azido-PEG, hydroxy-PEG, or BCN) attached to the indoxyl moiety, while three are isomers that include a PEG-ethynyl group at the 5-, 6-, or 7-position. All seven target compounds have been examined in indigoid-forming reactions upon treatment with β-glucuronidase from two different sources and rat liver tritosomes. Taken together, the results suggest the utility of tethered indoxyl-glucuronides for use in bioconjugation chemistry with a chromogenic readout under physiological conditions. DA - 2023/5/17/ PY - 2023/5/17/ DO - 10.3390/molecules28104143 VL - 28 IS - 10 SP - SN - 1420-3049 KW - chromogenic KW - dimerization KW - beta-glucuronidase KW - indigoid KW - indole KW - oxidation ER - TY - JOUR TI - Visual-Spatial Skills, Strategies, and Challenges to Extract, Represent, and Predict Stereochemical Outcomes of Cycloadditions Using a Hexagonal Prism Reference Frame AU - Echeverri-Jimenez, Emmanuel AU - Oliver-Hoyo, Maria T2 - JOURNAL OF CHEMICAL EDUCATION AB - The perception of 3D features from 2D representations depend on their number of salient features, recognizable canonical axes, and orientations. Informed by form-perception literature, we proposed a hexagonal prism as an external reference frame to identify positions of elements in relation to each other and the observer when studying Diels–Alder and other cycloaddition reactions. The hexagonal prism reference model (HPRM) provides three-dimensional features to cycloaddition transition states and an external reference to facilitate analysis of their stereochemical characteristics. A study to characterize the visual-spatial skills (VSS) and spatial challenges associated with extracting spatial information, representing spatial relations, and predicting stereochemical outcomes was completed with six graduate and six undergraduate students. Our findings show that different VSS predominate when solving different spatial tasks and that the patterns of VSS utilized by both graduate and undergraduates groups can be used to provide a more in-depth subcategorization of spatial strategies. The HPRM not only provides a resource for students to practice VSS and learn cycloaddition stereoselectivity, but also for instructors to promote effective strategies to predict stereochemistry. Since this study did not identify any nonspatial strategy, the HPRM proved to be effective in promoting students’ visuospatial thinking to solve spatial tasks. DA - 2023/6/15/ PY - 2023/6/15/ DO - 10.1021/acs.jchemed.2c00398 SP - SN - 1938-1328 KW - Graduate Education < Audience KW - Second-Year Undergraduate< Audience KW - Chemical Education Research < Domain KW - Organic Chemistry < Pedagogy KW - Inquiry-Based tenfold over wild-type Sb. Overall, this work systematically explores a broad collection of engineering strategies to improve protein secretion in Sb and highlights the ability of proteomics to highlight under-explored mediators of this process. In doing so, we created a set of probiotic strains that are capable of delivering a wide range of protein titers and therefore furthers the ability of Sb to deliver therapeutics to the gut and other settings to which it is adapted. DA - 2023/6/7/ PY - 2023/6/7/ DO - 10.1186/s12934-023-02117-y VL - 22 IS - 1 SP - SN - 1475-2859 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85161032784&partnerID=MN8TOARS ER - TY - JOUR TI - Spin dynamics of [1,2-C-13(2)]pyruvate hyperpolarization by parahydrogen in reversible exchange at micro Tesla fields AU - Browning, Austin AU - Macculloch, Keilian AU - TomHon, Patrick AU - Mandzhieva, Iuliia AU - Chekmenev, Eduard Y. AU - Goodson, Boyd M. AU - Lehmkuhl, Soeren AU - Theis, Thomas T2 - PHYSICAL CHEMISTRY CHEMICAL PHYSICS AB - Hyperpolarization of 13C-pyruvate via Signal Amplificaton By Reversibble Exchange (SABRE) is an important recent discovery because of both the relative simplicity of hyperpolarization and the central biological relevance of pyruvate as a biomolecular probe for in vitro or in vivo studies. Here, we analyze the [1,2-13C2]pyruvate-SABRE spin system and its field dependence theoretically and experimentally. We provide first-principles analysis of the governing 4-spin dihydride-13C2 Hamiltonian and numerical spin dynamics simulations of the 7-spin dihydride-13C2-CH3 system. The analytical and the numerical results are compared to matching systematic experiments. With these methods we unravel the observed spin state mixing of singlet states and triplet states at microTesla fields and we also analyze the dynamics during transfer from micro-Tesla field to high field for detection to understand the resulting spectra from the [1,2-13C2]pyruvate-SABRE system. DA - 2023/6/21/ PY - 2023/6/21/ DO - 10.1039/D3CP00843F VL - 25 IS - 24 SP - 16446-16458 SN - 1463-9084 UR - https://doi.org/10.1039/D3CP00843F ER - TY - JOUR TI - Water‐Soluble Fe(II) Complexes for Theranostic Application: Synthesis, Photoacoustic Imaging, and Photothermal Conversion AU - Delcroix, Maeva AU - Reddy Marri, Anil AU - Parant, Stéphane AU - Gros, Philippe C. AU - Bouché, Mathilde T2 - European Journal of Inorganic Chemistry AB - Abstract Significant effort focused on developing photoactivatable theranostics for localized image guided therapy of cancer by thermal ablation. In this context iron complexes were recently identified as photoactivatable theranostic agents with adequate biocompatibility and body clearance. Herein, a series of Fe II complexes bearing polypyridine or N‐heterocyclic carbenes is reported that rely on rational complex engineering to red‐shift their MLCT based excited‐state deactivation via a straightforward approach. The non‐radiative decay of their MLCT upon irradiation is exploited for theranostic purposes by combining both tracking in photoacoustic imaging (PA) and photothermal therapy (PTT). The influence of structural modifications introduced herein on the solubility and stability of the complexes in biorelevant aqueous media is discussed. The relationship between complexes’ design, production of contrast in photoacoustic and photothermal efficiency are explored to develop tailored PA/PTT theranostic agents. DA - 2023/5/25/ PY - 2023/5/25/ DO - 10.1002/ejic.202300138 VL - 5 SP - J2 - Eur J Inorg Chem LA - en OP - SN - 1434-1948 1099-0682 UR - http://dx.doi.org/10.1002/ejic.202300138 DB - Crossref KW - Bioinorganic chemistry KW - Iron KW - Optical properties KW - Photoacoustic imaging KW - Photothermal therapy ER - TY - JOUR TI - Revealing Excited-State Trajectories on Potential Energy Surfaces with Atomic Resolution in Real Time AU - Leshchev, Denis AU - J. S. Valentine, Andrew AU - Kim, Pyosang AU - Mills, Alexis W. AU - Roy, Subhangi AU - Chakraborty, Arnab AU - Biasin, Elisa AU - Haldrup, Kristoffer AU - Hsu, Darren J. J. AU - Kirschner, Matthew S. AU - Rimmerman, Dolev AU - Chollet, Matthieu AU - Glownia, J. Michael AU - Driel, Tim B. AU - Castellano, Felix N. AU - Li, Xiaosong AU - Chen, Lin X. X. T2 - ANGEWANDTE CHEMIE-INTERNATIONAL EDITION AB - Photoexcited molecular trajectories on potential energy surfaces (PESs) prior to thermalization are intimately connected to the photochemical reaction outcome. The excited-state trajectories of a diplatinum complex featuring photo-activated metal-metal σ-bond formation and associated Pt-Pt stretching motions were detected in real time using femtosecond wide-angle X-ray solution scattering. The observed motions correspond well with coherent vibrational wavepacket motions detected by femtosecond optical transient absorption. Two key coordinates for intersystem crossing have been identified, the Pt-Pt bond length and the orientation of the ligands coordinated with the platinum centers, along which the excited-state trajectories can be projected onto the calculated PESs of the excited states. This investigation has gleaned novel insight into electronic transitions occurring on the time scales of vibrational motions measured in real time, revealing ultrafast nonadiabatic or non-equilibrium processes along excited-state trajectories involving multiple excited-state PESs. DA - 2023/5/31/ PY - 2023/5/31/ DO - 10.1002/anie.202304615 VL - 5 SP - SN - 1521-3773 KW - Excited States KW - Intersystem Crossing KW - Platinum KW - Transition-Metal Complexes KW - Ultrafast Spectroscopy ER - TY - JOUR TI - Deep Dive into Eutectics: On the Origin of Deep and Elevated Eutectics AU - Martin, James D. D. AU - Shipman, Angela M. M. T2 - JOURNAL OF THE ELECTROCHEMICAL SOCIETY AB - There is growing interest in deep eutectic solvents (DES) for both chemical synthesis and materials applications. However, there is a general lack of understanding regarding what uniquely defines a system as a deep eutectic, and more importantly, what chemical properties determine unique eutectic behavior. In this work, we identify the thermodynamic basis for ideal eutectics relative to assumptions of ideal solutions. We then articulate the new Solvation Shell-Ionic Liquid (SSIL) and -Liquid Solvate (SSLS) model for solutions which identify the chemical/physical factors that create solution non-ideality and afford the ability to accurately calculate liquiduses, and thus the eutectics, of binary systems. The application of these models is demonstrated using diverse families of materials including aqueous salt solutions (ZnCl 2 , NaCl, KCl, and NH 4 NO 3 ), aqueous molecular solutions (sucrose and urea), solutions of naphthalene with aromatic (toluene, benzene, toluene, biphenyl and phenanthrene) and non-aromatic (ethanol, butanol, heptane and acetone) solvents, and the choline chloride:urea system for which the term DES was first introduced. The accurate description of the non-ideal enthalpic and entropic terms affords clear definition and prediction of both deep and elevated eutectics in diverse systems. DA - 2023/6/1/ PY - 2023/6/1/ DO - 10.1149/1945-7111/acdd27 VL - 170 IS - 6 SP - SN - 1945-7111 UR - https://doi.org/10.1149/1945-7111/acdd27 ER - TY - JOUR TI - Suite of Aptamer-Based Sensors for the Detection of Fentanyl and Its Analogues AU - Canoura, Juan AU - Liu, Yingzhu AU - Perry, Jacob AU - Willis, Connor AU - Xiao, Yi T2 - ACS SENSORS AB - Fentanyl and its analogues are potent synthetic opioids that are commonly abused and are currently the number one cause of drug overdose death in the United States. The ability to detect fentanyl with simple, rapid, and low-cost tools is crucial for forensics, medical care, and public safety. Conventional on-site testing options for fentanyl detection─including chemical spot tests, lateral-flow immunoassays, and portable Raman spectrometers─each have their own unique flaws that limit their analytical utility. Here, we have developed a series of new aptamer-based assays and sensors that can detect fentanyl as well as several of its analogues in a reliable, accurate, rapid, and economic manner. These include colorimetric, fluorescent, and electrochemical sensors, which can detect and quantify minute quantities of fentanyl and many of its analogues with no response to other illicit drugs, cutting agents, or adulterants─even in interferent-ridden binary mixtures containing as little as 1% fentanyl. Given the high performance of these novel analytical tools, we foresee the potential for routine use by medical and law enforcement personnel as well as the general public to aid in rapid and accurate fentanyl identification. DA - 2023/4/25/ PY - 2023/4/25/ DO - 10.1021/acssensors.2c02463 VL - 4 SP - SN - 2379-3694 KW - aptamers KW - fentanyl KW - analogue KW - electrochemistry KW - colorimetry KW - fluorescence KW - bioanalytical KW - sensors ER - TY - JOUR TI - Correction to “Mechanism-Driven Development of Group 10 Metal-Catalyzed Decarbonylative Coupling Reactions” AU - Lalloo, Naish AU - Brigham, Conor E. AU - Sanford, Melanie S. T2 - Accounts of Chemical Research AB - ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to “Mechanism-Driven Development of Group 10 Metal-Catalyzed Decarbonylative Coupling Reactions”Naish LallooNaish LallooMore by Naish Lalloohttps://orcid.org/0000-0001-9926-0387, Conor E. BrighamConor E. BrighamMore by Conor E. Brigham, and Melanie S. SanfordMelanie S. SanfordMore by Melanie S. Sanfordhttps://orcid.org/0000-0001-9342-9436Cite this: Acc. Chem. Res. 2023, 56, 12, 1683Publication Date (Web):May 25, 2023Publication History Received11 May 2023Published online25 May 2023Published inissue 20 June 2023https://doi.org/10.1021/acs.accounts.3c00277Copyright © 2023 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views633Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (728 KB) Get e-Alertsclose Get e-Alerts DA - 2023/6/20/ PY - 2023/6/20/ DO - 10.1021/acs.accounts.3c00277 UR - https://doi.org/10.1021/acs.accounts.3c00277 ER - TY - JOUR TI - Indoxyl-glucosides bearing tethers for enzymatically triggered cross-linking AU - Sato, Daisuke AU - Wu, Zhiyuan AU - Dou, Jinghuai AU - Son, Juno AU - Lindsey, Jonathan S. S. T2 - NEW JOURNAL OF CHEMISTRY AB - Tethered indoxyl-glucosides upon treatment with β-glucosidase under physiological conditions afford the corresponding indigoid dye via oxidative dimerization. DA - 2023/5/2/ PY - 2023/5/2/ DO - 10.1039/d2nj06267d VL - 47 IS - 17 SP - 8223-8242 SN - 1369-9261 ER - TY - JOUR TI - Greener Dyeing AU - Budhathoki-Uprety, Januka T2 - CHEMISTRY & INDUSTRY AB - Chemistry & IndustryVolume 87, Issue 3 p. 22-25 Sustainability Greener Dyeing First published: 21 March 2023 https://doi.org/10.1002/cind.10081AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Volume87, Issue3March 2023Pages 22-25 RelatedInformation DA - 2023/3// PY - 2023/3// DO - 10.1002/cind.10081 VL - 87 IS - 3 SP - 22-25 SN - 2047-6329 ER - TY - JOUR TI - Successive Short- and Long-Range Magnetic Ordering in Ba2Mn3(SeO3)(6) with Honeycomb Layers of Mn3+ Ions Alternating with Triangular Layers of Mn2+ Ions AU - Moskin, Artem AU - Kozlyakova, Ekaterina AU - Chung, Seung Hwan AU - Koo, Hyun-Joo AU - Whangbo, Myung-Hwan AU - Vasiliev, Alexander T2 - MATERIALS AB - Mixed-valent Ba2Mn2+Mn23+(SeO3)6 crystallizes in a monoclinic P21/c structure and has honeycomb layers of Mn3+ ions alternating with triangular layers of Mn2+ ions. We established the key parameters governing its magnetic structure by magnetization M and specific heat Cp measurements. The title compound exhibits a close succession of a short-range correlation order at Tcorr = 10.1 ± 0.1 K and a long-range Néel order at TN = 5.7 ± 0.1 K, and exhibits a metamagnetic phase transition at T < TN with hysteresis most pronounced at low temperatures. The causes for these observations were found using the spin exchange parameters evaluated by density functional theory calculations. The title compound represents a unique case in which uniform chains of integer spin Mn3+ (S = 2) ions interact with those of half-integer spin Mn2+ (S = 5/2) ions. DA - 2023/4// PY - 2023/4// DO - 10.3390/ma16072685 VL - 16 IS - 7 SP - SN - 1996-1944 KW - honeycomb lattice KW - triangular lattice KW - long-range magnetic order KW - short-range magnetic order KW - first principles' calculations ER - TY - JOUR TI - Magnetic transitions of hydrogenated H (x) CrO2 (x=0-2) monolayer from a ferromagnetic half-metal to antiferromagnetic insulator AU - Ouyang, Wenbin AU - Shi, Bowen AU - Su, Tianhao AU - Cheng, Xuli AU - Gao, Heng AU - Jia, Fanhao AU - Whangbo, Myung-Hwan AU - Ren, Wei T2 - JOURNAL OF PHYSICS-CONDENSED MATTER AB - Two-dimensional (2D) transition metal oxide monolayers are currently attracting great interest in materials research due to their versatility and tunable electronic and magnetic properties. In this study, we report the prediction of magnetic phase changes in HxCrO2(0 ⩽x⩽ 2) monolayer on the basis of first-principles calculations. As the H adsorption concentrationxincreases from 0 to 0.75, HxCrO2monolayer transforms from a ferromagnetic (FM) half-metal to a small-gap FM insulator. Whenx= 1.00 and 1.25, it behaves as a bipolar antiferromagnetic (AFM) insulator, and eventually becomes an AFM insulator asxincreases further up to 2.00. The results suggest that the magnetic properties of CrO2monolayer can be effectively controlled by hydrogenation, and that HxCrO2monolayers have the potential for realizing tunable 2D magnetic materials. Our results provide a comprehensive understanding of the hydrogenated 2D transition metal CrO2and provide a research method that can be used as a reference for the hydrogenation of other similar 2D materials. DA - 2023/8/2/ PY - 2023/8/2/ DO - 10.1088/1361-648X/acccc6 VL - 35 IS - 30 SP - SN - 1361-648X KW - density functional theory KW - first-principles calculations KW - two-dimensional materials KW - magnetic phase transition KW - hydrogen adsorption ER - TY - JOUR TI - Direct interpretation of the X-ray and neutron three-dimensional difference pair distribution functions (3D-DPDFs) of yttria-stabilized zirconia AU - Schmidt, Ella Mara AU - Neder, Reinhard B. AU - Martin, James D. AU - Minelli, Arianna AU - Lemee, Marie-Helene AU - Goodwin, Andrew L. T2 - ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE CRYSTAL ENGINEERING AND MATERIALS AB - Three-dimensional difference pair distribution functions (3D-ΔPDFs) from X-ray and neutron diffraction experiments are reported for yttria-stabilized zirconia (Zr0.82Y0.18O1.91). A quantitative analysis of the signatures in the three-dimensional difference pair distribution functions is used to establish that oxygen ions neighbouring a vacancy shift by 0.525 (5) Å along ⟨1, 0, 0⟩ towards the vacancy while metal ions neighbouring a vacancy shift by 0.465 (2) Å along ⟨1, 1, 1⟩ away from the vacancy. The neutron 3D-ΔPDF shows a tendency for vacancies to cluster along ⟨½, ½, ½⟩, which results in sixfold coordinated metal ions. DA - 2023/4// PY - 2023/4// DO - 10.1107/S205252062300121X VL - 79 SP - 138–147 SN - 2052-5206 KW - diffuse scattering KW - cubic zirconia KW - three-dimensional difference pair distribution KW - function (3D-Delta PDF). ER - TY - JOUR TI - Time of acquisition and high spatial resolution mass spectrometry imaging (vol 58, e4911, 2023) AU - Muddiman, David C. T2 - JOURNAL OF MASS SPECTROMETRY AB - Wang, MF, Joignant, AN, Sohn, AL, Garrard, KP, Muddiman, DC. Time of acquisition and high spatial resolution mass spectrometry imaging. J Mass Spectrom. 2023;e4911. doi:10.1002/jms.4911 In the article by Wang et al, there are some errors found in Figure 3. The arbitrary region of interest (ROI) total area was adjusted from 350 mm2 to 250 mm2 to increase the accuracy of Figure 3. The te,i and te,o values were recalculated according to the corrected arbitrary ROI area. Additionally in the original figure, the te,i value for “Arbitrary ROI” was incorrectly calculated with an area of 350 mm2. The tr equation was corrected to use the new “Arbitrary ROI” area of 250 mm2, and the parentheses were removed from the final ratio of “450 mm2/250 mm2” as the squaring only applies to the units and had been incorrectly applied to both the units and the numeric values. The final ratio value for tr was corrected to a value of 1.8. We apologize for this error. DA - 2023/5// PY - 2023/5// DO - 10.1002/jms.4922 VL - 58 IS - 5 SP - SN - 1096-9888 ER - TY - JOUR TI - On the importance of color in mass spectrometry imaging (vol 57, e4898, 2022) AU - Muddiman, David C. T2 - JOURNAL OF MASS SPECTROMETRY AB - Knizner, KT, Kibbe, RR, Garrard, KP, Nuñez, JR, Anderton, CR, Muddiman, DC. On the importance of color in mass spectrometry imaging. J Mass Spectrom. 2022; 57( 12):e4898. doi:10.1002/jms.4898 In the article by Knizner et al, the article type Research Article should be changed to Tutorial. We apologize for this error. DA - 2023/5// PY - 2023/5// DO - 10.1002/jms.4921 VL - 58 IS - 5 SP - SN - 1096-9888 ER - TY - JOUR TI - Achieving Sub-Parts-per-Million Mass Measurement Accuracy on an Orbitrap Mass Spectrometry Imaging Platform without Automatic Gain Control AU - Kibbe, Russell R. AU - Muddiman, David C. T2 - JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY AB - The collection of profile data is standard practice within the field of mass spectrometry (MS). However, profile data collection often results in large data files that require extensive processing times, especially in mass spectrometry imaging (MSI) studies where thousands of high-resolution scans are recorded. Natively collecting centroid MS data is an alternative that effectively reduces both the resulting file size and the data processing time. Herein, high-resolution accurate mass (HRAM) Orbitrap MSI data on mouse liver tissue sections without automatic gain control (AGC) were natively collected in both profile and centroid modes and compared based on the file size and processing time. Additionally, centroid data were evaluated against the profile data with regard to the spectra integrity, mass measurement accuracy (MMA), and the number of lipid annotations to ensure that centroid data did not compromise the data quality. For both native and postacquisition centroided data, the variation in mass measurement accuracy decreased relative to the profile data collection. Furthermore, centroid data collection increased the number of METASPACE database annotations indicating higher sensitivity and greater accuracy for lipid annotation compared to native profile data collection. Profile MSI data was shown to have a higher likelihood of false positive identifications due to an increased number of data points on either side of the peaks, whereas the same trend was not observed in data collected in native centroid data collection. This publication explores and explains the importance in properly centroiding MSI data, either natively or by adequate centroiding methods, to obtain the most accurate information and come to the best conclusions. These data support that natively collecting centroid data significantly improves MMA to sub-ppm levels without AGC and reduces false positive annotations. DA - 2023/4/25/ PY - 2023/4/25/ DO - 10.1021/jasms.3c00004 VL - 4 SP - SN - 1879-1123 KW - centroid KW - mass measurement accuracy KW - IR-MALDESI KW - mass spectrometry imaging KW - Orbitrap KW - automatic gain control ER - TY - JOUR TI - Parahydrogen in Reversible Exchange Induces Long-Lived 15N Hyperpolarization of Anticancer Drugs Anastrozole and Letrozole AU - MacCulloch, Keilian AU - Browning, Austin AU - TomHon, Patrick AU - Lehmkuhl, Soeren AU - Chekmenev, Eduard Y. AU - Theis, Thomas T2 - ANALYTICAL CHEMISTRY AB - Hyperpolarization modalities overcome the sensitivity limitations of NMR and unlock new applications. Signal amplification by reversible exchange (SABRE) is a particularly cheap, quick, and robust hyperpolarization modality. Here, we employ SABRE for simultaneous chemical exchange of parahydrogen and nitrile-containing anticancer drugs (letrozole or anastrozole) to enhance 15N polarization. Distinct substrates require unique optimal parameter sets, including temperature, magnetic field, or a shaped magnetic field profile. The fine tuning of these parameters for individual substrates is demonstrated here to maximize 15N polarization. After optimization, including the usage of pulsed μT fields, the 15N nuclei on common anticancer drugs, letrozole and anastrozole, can be polarized within 1-2 min. The hyperpolarization can exceed 10%, corresponding to 15N signal enhancement of over 280,000-fold at a clinically relevant magnetic field of 1 T. This sensitivity gain enables polarization studies at naturally abundant 15N enrichment level (0.4%). Moreover, the nitrile 15N sites enable long-lasting polarization storage with [15N]T1 over 9 min, enabling signal detection from a single hyperpolarization cycle for over 30 min. DA - 2023/5/10/ PY - 2023/5/10/ DO - 10.1021/acs.analchem.2c04817 VL - 5 IS - 20 SP - SN - 1520-6882 UR - https://doi.org/10.1021/acs.analchem.2c04817 ER - TY - JOUR TI - Celebrating Kenneth D. Karlin for his ACS Award for Distinguished Service in the Advancement of Inorganic Chemistry AU - Lucas, Heather R. AU - Kim, Eunsuk AU - Ghiladi, Reza A. T2 - JOURNAL OF INORGANIC BIOCHEMISTRY AB - Capillary electrophoresis was used to estimate the solvolytic dissociation rate (kd) of metal complexes of deferasirox (DFX, H3L), a drug used to treat iron overload. Inert CoIIIL23− did not dissociate. The estimated kd value for FeIIIL23− was (2.7 ± 0.3) × 10−4 s−1 (298 K, pH 7.4). The kd values of other complexes (AlIIIL23−, NiIIL24−, and MnIIL−) were in the range 10−3–10−4 s−1. In contrast, ZnIIL− and CuIIL− were too labile to allow kd estimation. The fact that the half-life of FeIIIL23− (43.3 min) is shorter than the blood half-life of DFX (8–16 h) implies that the blood concentration of DFX should be high enough to prevent dissociation of FeIIIL23−. The possibility of a safer iron-chelation therapy that avoids excretion of other essential metal ions such as ZnII is discussed, highlighting the importance of selectivity in terms of kinetic stability. DA - 2023/4// PY - 2023/4// DO - 10.1016/j.jinorgbio.2023.112142 VL - 241 SP - SN - 1873-3344 ER - TY - JOUR TI - Changes in metabolic landscapes shape divergent but distinct mutational signatures and cytotoxic consequences of redox stress AU - Degtyareva, Natalya P. AU - Placentra, Victoria C. AU - Gabel, Scott A. AU - Klimczak, Leszek J. AU - Gordenin, Dmitry A. AU - Wagner, Brett A. AU - Buettner, Garry R. AU - Mueller, Geoffrey A. AU - Smirnova, Tatyana I AU - Doetsch, Paul W. T2 - NUCLEIC ACIDS RESEARCH AB - Abstract Mutational signatures discerned in cancer genomes, in aging tissues and in cells exposed to toxic agents, reflect complex processes underlying transformation of cells from normal to dysfunctional. Due to its ubiquitous and chronic nature, redox stress contributions to cellular makeover remain equivocal. The deciphering of a new mutational signature of an environmentally-relevant oxidizing agent, potassium bromate, in yeast single strand DNA uncovered a surprising heterogeneity in the mutational signatures of oxidizing agents. NMR-based analysis of molecular outcomes of redox stress revealed profound dissimilarities in metabolic landscapes following exposure to hydrogen peroxide versus potassium bromate. The predominance of G to T substitutions in the mutational spectra distinguished potassium bromate from hydrogen peroxide and paraquat and mirrored the observed metabolic changes. We attributed these changes to the generation of uncommon oxidizing species in a reaction with thiol-containing antioxidants; a nearly total depletion of intracellular glutathione and a paradoxical augmentation of potassium bromate mutagenicity and toxicity by antioxidants. Our study provides the framework for understanding multidimensional processes triggered by agents collectively known as oxidants. Detection of increased mutational loads associated with potassium bromate-related mutational motifs in human tumors may be clinically relevant as a biomarker of this distinct type of redox stress. DA - 2023/4/20/ PY - 2023/4/20/ DO - 10.1093/nar/gkad305 VL - 4 SP - SN - 1362-4962 ER - TY - JOUR TI - Adaptive basis sets for practical quantum computing AU - Kwon, Hyuk-Yong AU - Curtin, Gregory M. M. AU - Morrow, Zachary AU - Kelley, C. T. AU - Jakubikova, Elena T2 - INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY AB - Abstract Electronic structure calculations on small systems such as H 2 , H 2 O, LiH, and BeH 2 with chemical accuracy are still a challenge for the current generation of noisy intermediate‐scale quantum (NISQ) devices. One of the reasons is that due to the device limitations, only minimal basis sets are commonly applied in quantum chemical calculations, which allows one to keep the number of qubits employed in the calculations at a minimum. However, the use of minimal basis sets leads to very large errors in the computed molecular energies as well as potential energy surface shapes. One way to increase the accuracy of electronic structure calculations is through the development of small basis sets better suited for quantum computing. In this work, we show that the use of adaptive basis sets, in which exponents and contraction coefficients depend on molecular structure, provides an easy way to dramatically improve the accuracy of quantum chemical calculations without the need to increase the basis set size and thus the number of qubits utilized in quantum circuits. As a proof of principle, we optimize an adaptive minimal basis set for quantum computing calculations on an H 2 molecule, in which exponents and contraction coefficients depend on the HH distance, and apply it to the generation of H 2 potential energy surface on IBM‐Q quantum devices. The adaptive minimal basis set reaches the accuracy of the double‐zeta basis sets, thus allowing one to perform double‐zeta quality calculations on quantum devices without the need to utilize twice as many qubits in simulations. This approach can be extended to other molecular systems and larger basis sets in a straightforward manner. DA - 2023/4/5/ PY - 2023/4/5/ DO - 10.1002/qua.27123 VL - 4 SP - SN - 1097-461X KW - adaptive basis set KW - potential energy surface KW - quantum computing ER - TY - JOUR TI - Journal of Inorganic Biochemistry - Karlin Special Issue AU - Lucas, Heather R. AU - Kim, Eunsuk AU - Ghiladi, Reza A. T2 - JOURNAL OF INORGANIC BIOCHEMISTRY AB - The Cytochrome P450 (CYP450) superfamily has been the subject of intense research for over six decades. Here the HU227 strain of E. coli, lacking the δ-aminolevulinic acid (δ-ALA) synthase gene, was employed, along with [5-13C] δ-ALA, in the heterologous expression of P450cam harboring a prosthetic group labeled with 13C at the four methine carbons (Cm) and pyrrole Cα positions. The product was utilized as a proof of principle strategy for defining and refining solution phase active site structure in cytochrome P450cam, providing proton-to-proton distances from 13CmH to protons on bound substrate or nearby amino acid residues, using short mixing time 2D or 3D NOESY-HMQC methods. The results reveal the interesting finding that 2D 13C-filtered NOESY-HMQC can be used to obtain distances between protons on labeled 13C to positions of protons nearby in the active site, confirming the utility of this NMR-based approach to probing active site structure under physiological conditions. Such 13C-heme-filtered NOE data complement X-ray crystallographic and T1-based NMR measurements; and, may also be of potentially significant utility in furnishing experimental distance constraints in validations of docking routines commonly employed for determining the relative affinities and binding orientations of drug candidates with CYP450s. DA - 2023/4// PY - 2023/4// DO - 10.1016/j.jinorgbio.2023.112143 VL - 241 SP - SN - 1873-3344 ER - TY - JOUR TI - Crystal Engineering of Two Light and Pressure Responsive Physisorbents AU - Castell, Dominic C. AU - Nikolayenko, Varvara I. AU - Sensharma, Debobroto AU - Koupepidou, Kyriaki AU - Forrest, Katherine A. AU - Solanilla-Salinas, Carlos J. AU - Space, Brian AU - Barbour, Leonard J. AU - Zaworotko, Michael J. T2 - ANGEWANDTE CHEMIE-INTERNATIONAL EDITION AB - An emerging strategy in the design of efficient gas storage technologies is the development of stimuli-responsive physisorbents which undergo transformations in response to a particular stimulus, such as pressure, heat or light. Herein, we report two isostructural light modulated adsorbents (LMAs) containing bis-3-thienylcyclopentene (BTCP), LMA-1 [Cd(BTCP)(DPT)2 ] (DPT=2,5-diphenylbenzene-1,4-dicarboxylate) and LMA-2 [Cd(BTCP)(FDPT)2 ] (FDPT=5-fluoro-2,diphenylbenzene-1,4-dicarboxylate). Both LMAs undergo pressure induced switching transformations from non-porous to porous via adsorption of N2 , CO2 and C2 H2 . LMA-1 exhibited multi-step adsorption while LMA-2 showed a single-step adsorption isotherm. The light responsive nature of the BTPC ligand in both frameworks was exploited with irradiation of LMA-1 resulting in a 55 % maximum reduction of CO2 uptake at 298 K. This study reports the first example of a switching sorbent (closed to open) that can be further modulated by light. DA - 2023/3/30/ PY - 2023/3/30/ DO - 10.1002/anie.202219039 VL - 3 SP - SN - 1521-3773 KW - Gas-Sorption KW - Photochromism KW - SCXRD KW - Stimuli-Responsive Compounds KW - Switching ER - TY - JOUR TI - Lipidomic Analysis of Mouse Brain to Evaluate the Efficacy and Preservation of Different Tissue Preparatory Techniques by IR-MALDESI-MSI AU - Wang, Mary F. AU - Sohn, Alexandria L. AU - Samal, Juhi AU - Erning, Kevin AU - Segura, Tatiana AU - Muddiman, David C. T2 - JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY AB - Numerous preparatory methods have been developed to preserve the cellular and structural integrity of various biological tissues for different -omics studies. Herein, two preparatory methods for mass spectrometry imaging (MSI) were evaluated, fresh-frozen and sucrose-embedded, paraformaldehyde (PFA) fixed, in terms of ion abundance, putative lipid identifications, and preservation of analyte spatial distributions. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI)-MSI was utilized to compare the preparatory methods of interest with and without the use of the conventional ice matrix. There were 2.5-fold and 1.6-fold more lipid species putatively identified in positive- and negative-ion modes, respectively, for sucrose-embedded, PFA-fixed tissues without an ice matrix relative to the current IR-MALDESI-MSI gold-standard, fresh-frozen tissue preparation with an exogenous ice matrix. Furthermore, sucrose-embedded tissues demonstrated improved spatial distribution of ions resulting from the cryo-protective property of sucrose and paraformaldehyde fixation. Evidence from these investigations supports sucrose-embedding without ice matrix as an alternative preparatory technique for IR-MALDESI-MSI. DA - 2023/3/29/ PY - 2023/3/29/ DO - 10.1021/jasms.2c00353 VL - 3 SP - SN - 1879-1123 KW - IR-MALDESI KW - mass spectrometry imaging KW - sucrose KW - PFA ER - TY - JOUR TI - Surface Immobilization of a Re(I) Tricarbonyl Phenanthroline Complex to Si(111) through Sonochemical Hydrosilylation AU - Huffman, Brittany L. AU - Bein, Gabriella P. AU - Atallah, Hala AU - Donley, Carrie L. AU - Alameh, Reem T. AU - Wheeler, Jonathan P. AU - Durand, Nicolas AU - Harvey, Alexis K. AU - Kessinger, Matthew C. AU - Chen, Cindy Y. AU - Fakhraai, Zahra AU - Atkin, Joanna M. AU - Castellano, Felix N. AU - Dempsey, Jillian L. T2 - ACS Applied Materials & Interfaces AB - A sonochemical-based hydrosilylation method was employed to covalently attach a rhenium tricarbonyl phenanthroline complex to silicon(111). fac-Re(5-(p-Styrene)-phen)(CO)3Cl (5-(p-styrene)-phen = 5-(4-vinylphenyl)-1,10-phenanthroline) was reacted with hydrogen-terminated silicon(111) in an ultrasonic bath to generate a hybrid photoelectrode. Subsequent reaction with 1-hexene enabled functionalization of remaining atop Si sites. Attenuated total reflectance-Fourier transform infrared spectroscopy confirms attachment of the organometallic complex to silicon without degradation of the organometallic core, supporting hydrosilylation as a strategy for installing coordination complexes that retain their molecular integrity. Detection of Re(I) and nitrogen by X-ray photoelectron spectroscopy (XPS) further support immobilization of fac-Re(5-(p-styrene)-phen)(CO)3Cl. Cyclic voltammetry and electrochemical impedance spectroscopy under white light illumination indicate that fac-Re(5-(p-styrene)-phen)(CO)3Cl undergoes two electron reductions. Mott-Schottky analysis indicates that the flat band potential is 239 mV more positive for p-Si(111) co-functionalized with both fac-Re(5-(p-styrene)-phen)(CO)3Cl and 1-hexene than when functionalized with 1-hexene alone. XPS, ultraviolet photoelectron spectroscopy, and Mott-Schottky analysis show that functionalization with fac-Re(5-(p-styrene)-phen)(CO)3Cl and 1-hexene introduces a negative interfacial dipole, facilitating reductive photoelectrochemistry. DA - 2023/1/11/ PY - 2023/1/11/ DO - 10.1021/acsami.2c17078 UR - https://doi.org/10.1021/acsami.2c17078 ER - TY - JOUR TI - Panchromatic light harvesting and record power conversion efficiency for carboxylic/cyanoacrylic Fe(ii) NHC co-sensitized FeSSCs AU - Reddy-Marri, Anil AU - Marchini, Edoardo AU - Cabanes, Valentin Diez AU - Argazzi, Roberto AU - Pastore, Mariachiara AU - Caramori, Stefano AU - Gros, Philippe C. T2 - Chemical Science AB - Fe(ii) pyridyl-NHC sensitizers bearing thienylcyanoacrylic (ThCA) anchoring groups have been designed and characterized with the aim of enhancing the metal to surface charge separation and the light harvesting window in iron-sensitized DSSCs (FeSSCs). In these new Fe(ii) dyes, the introduction of the ThCA moiety remarkably extended the spectral response and the photocurrent, in comparison with their carboxylic analogues. The co-sensitization based on a mixture of a carboxylic and a ThCA-iron complex produced a panchromatic absorption, up to 800 nm and the best photocurrent and efficiency (Jsc: 9 mA cm-2 and PCE: 2%) ever reported for an FeSSC. DA - 2023/// PY - 2023/// DO - 10.1039/D2SC05971A VL - 14 IS - 16 SP - 4288-4301 J2 - Chem. Sci. LA - en OP - SN - 2041-6520 2041-6539 UR - http://dx.doi.org/10.1039/D2SC05971A DB - Crossref ER - TY - JOUR TI - LIGHT-SABRE Hyperpolarizes 1-13C-Pyruvate Continuously without Magnetic Field Cycling AU - Pravdivtsev, Andrey N. AU - Buckenmaier, Kai AU - Kempf, Nicolas AU - Stevanato, Gabriele AU - Scheffler, Klaus AU - Engelmann, Joern AU - Plaumann, Markus AU - Koerber, Rainer AU - Hoevener, Jan-Bernd AU - Theis, Thomas T2 - JOURNAL OF PHYSICAL CHEMISTRY C AB - Nuclear spin hyperpolarization enables real-time observation of metabolism and intermolecular interactions in vivo. 1-13C-pyruvate is the leading hyperpolarized tracer currently under evaluation in several clinical trials as a promising molecular imaging agent. Still, the quest for a simple, fast, and efficient hyperpolarization technique is ongoing. Here, we describe that continuous, weak irradiation in the audio-frequency range of the 13C spin at the 121 μT magnetic field (approximately twice Earth's field) enables spin order transfer from parahydrogen to 13C magnetization of 1-13C-pyruvate. These so-called LIGHT-SABRE pulses couple nuclear spin states of parahydrogen and pyruvate via the J-coupling network of reversibly exchanging Ir-complexes. Using ∼100% parahydrogen at ambient pressure, we polarized 51 mM 1-13C-pyruvate in the presence of 5.1 mM Ir-complex continuously and repeatedly to a polarization of 1.1% averaged over free and catalyst-bound pyruvate. The experiments were conducted at -8 °C, where almost exclusively bound pyruvate was observed, corresponding to an estimated 11% polarization on bound pyruvate. The obtained hyperpolarization levels closely match those obtained via SABRE-SHEATH under otherwise identical conditions. The creation of three different types of spin orders was observed: transverse 13C magnetization along the applied magnetic field, 13C z-magnetization along the main field B0, and 13C-1H zz-spin order. With a superconducting quantum interference device (SQUID) for detection, we found that the generated spin orders result from 1H-13C J-coupling interactions, which are not visible even with our narrow linewidth below 0.3 Hz and at -8 °C. DA - 2023/4/4/ PY - 2023/4/4/ DO - 10.1021/acs.jpcc.3c01128 VL - 4 IS - 14 SP - SN - 1932-7455 UR - https://doi.org/10.1021/acs.jpcc.3c01128 ER - TY - JOUR TI - Bile salt hydrolases shape the bile acid landscape and restrict Clostridioides difficile growth in the murine gut AU - Foley, Matthew H. AU - Walker, Morgan E. AU - Stewart, Allison K. AU - O'Flaherty, Sarah AU - Gentry, Emily C. AU - Patel, Shakshi AU - Beaty, Violet V. AU - Allen, Garrison AU - Pan, Meichen AU - Simpson, Joshua B. AU - Perkins, Caroline AU - Vanhoy, Molly E. AU - Dougherty, Michael K. AU - McGill, Sarah K. AU - Gulati, Ajay S. AU - Dorrestein, Pieter C. AU - Baker, Erin S. AU - Redinbo, Matthew R. AU - Barrangou, Rodolphe AU - Theriot, Casey M. T2 - NATURE MICROBIOLOGY AB - Bile acids (BAs) mediate the crosstalk between human and microbial cells and influence diseases including Clostridioides difficile infection (CDI). While bile salt hydrolases (BSHs) shape the BA pool by deconjugating conjugated BAs, the basis for their substrate selectivity and impact on C. difficile remain elusive. Here we survey the diversity of BSHs in the gut commensals Lactobacillaceae, which are commonly used as probiotics, and other members of the human gut microbiome. We structurally pinpoint a loop that predicts BSH preferences for either glycine or taurine substrates. BSHs with varying specificities were shown to restrict C. difficile spore germination and growth in vitro and colonization in pre-clinical in vivo models of CDI. Furthermore, BSHs reshape the pool of microbial conjugated bile acids (MCBAs) in the murine gut, and these MCBAs can further restrict C. difficile virulence in vitro. The recognition of conjugated BAs by BSHs defines the resulting BA pool, including the expansive MCBAs. This work provides insights into the structural basis of BSH mechanisms that shape the BA landscape and promote colonization resistance against C. difficile. DA - 2023/3/13/ PY - 2023/3/13/ DO - 10.1038/s41564-023-01337-7 VL - 3 SP - SN - 2058-5276 ER - TY - JOUR TI - Impact of wavelength and spot size on laser depth of focus: Considerations for mass spectrometry imaging of non-flat samples AU - Joignant, Alena N. N. AU - Xi, Ying AU - Muddiman, David C. C. T2 - JOURNAL OF MASS SPECTROMETRY AB - Biospecimens with nearly flat surfaces on a flat stage are typically required for laser-based mass spectrometry imaging (MSI) techniques. However, sampling stages are rarely perfectly level, and accounting for this and the need to accommodate non-flat samples requires a deeper understanding of the laser beam depth of focus. In ablation-based MSI methods, a laser is focused on top of the sample surface, ensuring that the sample is at the focal point or remains within depth of focus. In general, the depth of focus of a given laser is related to the beam quality (M2 ) and the wavelength (λ). However, because laser is applied on a biological sample, other variables can also impact the depth of focus, which could affect the robustness of the MSI techniques for diverse sample types. When the height of a sample ranges outside of the depth of focus, ablated area and the corresponding ion abundances may vary as well, increasing the variability of results. In this tutorial, we examine the parameters and equations that describe the depth of focus of a Gaussian laser beam. Additionally, we describe several approaches that account for surface roughness exceeding the depth of focus of the laser. DA - 2023/3/14/ PY - 2023/3/14/ DO - 10.1002/jms.4914 VL - 3 SP - SN - 1096-9888 KW - depth of focus KW - laser wavelength KW - mass spectrometry imaging KW - spatial resolution KW - surface roughness ER - TY - JOUR TI - Mechanistic Studies of Aziridine Formation Catalyzed by Mononuclear Non-Heme Iron Enzymes AU - Cha, Lide AU - Paris, Jared C. AU - Zanella, Brady AU - Spletzer, Martha AU - Yao, Angela AU - Guo, Yisong AU - Chang, Wei-chen T2 - JOURNAL OF THE AMERICAN CHEMICAL SOCIETY AB - Aziridines are compounds with a nitrogen-containing three-membered ring. When it is incorporated into natural products, the reactivity of the strained ring often drives the biological activities of aziridines. Despite its importance, the enzymes and biosynthetic strategies deployed to install this reactive moiety remain understudied. Herein, we report the use of in silico methods to identify enzymes with potential aziridine-installing (aziridinase) functionality. To validate candidates, we reconstitute enzymatic activity in vitro and demonstrate that an iron(IV)-oxo species initiates aziridine ring closure by the C–H bond cleavage. Furthermore, we divert the reaction pathway from aziridination to hydroxylation using mechanistic probes. This observation, isotope tracing experiments using H218O and 18O2, and quantitative product analysis, provide evidence for the polar capture of a carbocation species by the amine in the pathway to aziridine installation. DA - 2023/3/13/ PY - 2023/3/13/ DO - 10.1021/jacs.2c12664 VL - 3 SP - SN - 1520-5126 ER - TY - JOUR TI - "Super stable" Blatter radicals through ArLi addition: surprising chemistry of 7-(trifluoromethyl)benzo[e][1,2,4]triazine AU - Obijalska, Emilia AU - Pietrzak, Anna AU - Constantinides, Christos. P. P. AU - Sommer, Roger. D. D. AU - Kaszynski, Piotr T2 - CHEMICAL COMMUNICATIONS AB - Addition of PhLi to 7-(CF3)benzo[e][1,2,4]triazine at -78 °C gives the "super stable" Blatter radical in high yields, while above -5 °C two additional products are formed. XRD analysis revealed the formation of a "trimer" and a benzo[f][1,2,4]triazepine via a novel mechanism. The latter is formed from the anion generated from the isolated radical, which suggests its instability in organic batteries. DA - 2023/3/7/ PY - 2023/3/7/ DO - 10.1039/d3cc00832k SP - SN - 1364-548X ER - TY - JOUR TI - AlphaFlow: autonomous discovery and optimization of multi-step chemistry using a self-driven fluidic lab guided by reinforcement learning AU - Volk, Amanda A. AU - Epps, Robert W. AU - Yonemoto, Daniel T. AU - Masters, Benjamin S. AU - Castellano, Felix N. AU - Reyes, Kristofer G. AU - Abolhasani, Milad T2 - NATURE COMMUNICATIONS AB - Abstract Closed-loop, autonomous experimentation enables accelerated and material-efficient exploration of large reaction spaces without the need for user intervention. However, autonomous exploration of advanced materials with complex, multi-step processes and data sparse environments remains a challenge. In this work, we present AlphaFlow, a self-driven fluidic lab capable of autonomous discovery of complex multi-step chemistries. AlphaFlow uses reinforcement learning integrated with a modular microdroplet reactor capable of performing reaction steps with variable sequence, phase separation, washing, and continuous in-situ spectral monitoring. To demonstrate the power of reinforcement learning toward high dimensionality multi-step chemistries, we use AlphaFlow to discover and optimize synthetic routes for shell-growth of core-shell semiconductor nanoparticles, inspired by colloidal atomic layer deposition (cALD). Without prior knowledge of conventional cALD parameters, AlphaFlow successfully identified and optimized a novel multi-step reaction route, with up to 40 parameters, that outperformed conventional sequences. Through this work, we demonstrate the capabilities of closed-loop, reinforcement learning-guided systems in exploring and solving challenges in multi-step nanoparticle syntheses, while relying solely on in-house generated data from a miniaturized microfluidic platform. Further application of AlphaFlow in multi-step chemistries beyond cALD can lead to accelerated fundamental knowledge generation as well as synthetic route discoveries and optimization. DA - 2023/3/14/ PY - 2023/3/14/ DO - 10.1038/s41467-023-37139-y VL - 14 IS - 1 SP - SN - 2041-1723 UR - https://doi.org/10.1038/s41467-023-37139-y ER - TY - JOUR TI - Discovery Proteomics and Absolute Protein Quantification Can Be Performed Simultaneously on an Orbitrap-Based Mass Spectrometer AU - Williams, Taufika Islam AU - Kowalchyk, Cara AU - Collins, Leonard B. AU - Reading, Benjamin J. T2 - ACS OMEGA AB - Mass spectrometry (MS) has steadily moved into the forefront of quantification-centered protein research. Protein cleavage isotope dilution MS is a proven way for quantifying proteins by using an isotope-labeled analogue of a peptide fragment of the parent protein as an internal standard. Parallel reaction monitoring (PRM) has become the go-to approach for such quantification on an Orbitrap-based instrument as it is assumed that the instrument sensitivity is enhanced. We performed a comparative study on data-dependent acquisition (DDA) and PRM-based workflows to quantify egg yolk protein precursors or vitellogenins (VTGs) Aa, Ab, and C in striped bass (Morone saxatilis). VTG proportions serve as a developmental measure of egg quality, possibly changing with the environment, and have been studied as an indicator of the health of North Carolina stocks. Based on single-factor analysis of variance comparisons of mean VTG amounts across fish from the same sample groupings, our results indicate that there is no statistical difference between MS1-based and MS2-based VTG quantification. We further conclude that DDA is able to deliver both discovery data and absolute quantification data in the same experiment. DA - 2023/3/22/ PY - 2023/3/22/ DO - 10.1021/acsomega.2c07614 VL - 3 IS - 13 SP - SN - 2470-1343 UR - https://doi.org/10.1021/acsomega.2c07614 ER - TY - JOUR TI - Facile hyperpolarization chemistry for molecular imaging and metabolic tracking of [1-13C]pyruvate in vivo AU - Browning, Austin AU - MacCulloch, Keilian AU - Bedoya, David Guarin AU - Dedesma, Carlos AU - Goodson, Boyd M AU - Rosen, Matthew S AU - Chekmenev, Eduard Y AU - Yen, Yi-Fen AU - TomHon, Patrick AU - Theis, Thomas T2 - ChemRxiv AB - Hyperpolarization chemistry based on reversible exchange of parahydrogen, also known as Signal Amplification By Reversible Exchange (SABRE), is a particularly simple approach to attain high levels of nuclear spin hyperpolarization, which can enhance NMR and MRI signals by many orders of magnitude. SABRE has received significant attention in the scientific community since its inception because of its relative experimental simplicity and its broad applicability to a wide range of molecules, however in vivo detection of molecular probes hyperpolarized by SABRE has remained elusive. Here we describe the first demonstration of SABRE-hyperpolarized contrast detected in vivo, specifically using hyperpolarized [1-13C]pyruvate. A biocompatible formulation of hyperpolarized [1-13C]pyruvate was injected into healthy Sprague Dawley and Wistar rats, and metabolic conversion of pyruvate to lactate, alanine, pyruvate-hydrate, and bicarbonate was detected. Measurements were performed on the liver and kidney at 4.7 T via time-resolved spectroscopy and chemical-shift-resolved MRI. In addition, whole-body metabolic measurements were obtained using a cryogen-free 1.5 T MRI system, illustrating the utility of combining lower-cost MRI systems with simple, low-cost hyperpolarization chemistry to develop scalable, next-generation molecular imaging. DA - 2023/3/20/ PY - 2023/3/20/ DO - 10.26434/chemrxiv-2023-4dqkx UR - https://doi.org/10.26434/chemrxiv-2023-4dqkx ER - TY - JOUR TI - Towards panchromatic Fe(ii) NHC sensitizers via HOMO inversion AU - Marri, Anil Reddy AU - Marekha, Bogdan AU - Penfold, Thomas AU - Haacke, Stefan AU - Gros, Philippe C. T2 - Inorganic Chemistry Frontiers AB - Fused polythiophenes attached to Fe( ii )NHC complexes induced a mixing of the t 2g and π HOMO orbitals promoting 80 nm red-shift of the MLCT transition, 3 fold increase of the molar extinction coefficient and 3 MLCT excited state lifetime up to 18 ps. DA - 2023/// PY - 2023/// DO - 10.1039/D2QI01903E VL - 10 IS - 1 SP - 118-126 J2 - Inorg. Chem. Front. LA - en OP - SN - 2052-1553 UR - http://dx.doi.org/10.1039/D2QI01903E DB - Crossref ER - TY - JOUR TI - SMART: A data reporting standard for mass spectrometry imaging AU - Xi, Ying AU - Sohn, Alexandria L. AU - Joignant, Alena N. AU - Cologna, Stephanie M. AU - Prentice, Boone M. AU - Muddiman, David C. T2 - JOURNAL OF MASS SPECTROMETRY AB - Mass spectrometry imaging (MSI) is an important analytical technique that simultaneously reports the spatial location and abundance of detected ions in biological, chemical, clinical, and pharmaceutical studies. As MSI grows in popularity, it has become evident that data reporting varies among different research groups and between techniques. The lack of consistency in data reporting inherently creates additional challenges in comparing intra- and inter-laboratory MSI data. In this tutorial, we propose a unified data reporting system, SMART, based on the common features shared between techniques. While there are limitations to any reporting system, SMART was decided upon after significant discussion to more easily understand and benchmark MSI data. SMART is not intended to be comprehensive but rather capture essential baseline information for a given MSI study; this could be within a study (e.g., effect of spot size on the measured ion signals) or between two studies (e.g., different MSI platform technologies applied to the same tissue type). This tutorial does not attempt to address the confidence with which annotations are made nor does it deny the importance of other parameters that are not included in the current SMART format. Ultimately, the goal of this tutorial is to discuss the necessity of establishing a uniform reporting system to communicate MSI data in publications and presentations in a simple format to readily interpret the parameters and baseline outcomes of the data. DA - 2023/2// PY - 2023/2// DO - 10.1002/jms.4904 VL - 58 IS - 2 SP - SN - 1096-9888 KW - data reporting standards KW - mass spectrometry imaging ER - TY - JOUR TI - Hydrothermally Derived Green Carbon Dots from Broccoli Water Extracts: Decreased Toxicity, Enhanced Free-Radical Scavenging, and Anti-Inflammatory Performance AU - Deng, Wen-wen AU - Zang, Chuan-ru AU - Li, Qiu-chen AU - Sun, Bo AU - Mei, Xue-ping AU - Bai, Lu AU - Shang, Xin-miao AU - Deng, Ying AU - Xiao, Ya-qian AU - Ghiladi, Reza A. AU - Lorimer, George H. AU - Zhang, Xue-ji AU - Wang, Jun T2 - ACS BIOMATERIALS SCIENCE & ENGINEERING AB - Biomass carbon dots (CDs) derived from natural plants possess the advantages of low cost, photostability, and excellent biocompatibility, with potential applications in chemical sensing, bioimaging, and nanomedicine. However, the development of biomass CDs with excellent antioxidant activity and good biocompatibility is still a challenge. Herein, we propose a hypothesis for enhancing the antioxidant capacity of biomass CDs based on precursor optimization, extraction solvent, and other conditions with broccoli as the biomass. Compared to broccoli water extracts, broccoli powders, and broccoli organic solvent extracts, CDs derived from broccoli water extracts (BWE-CDs) have outstanding antioxidant properties due to the abundant C═C, carbonyl, and amino groups on their surface. After optimization of the preparation condition, the obtained BWE-CDs exhibit excellent free-radical scavenging activity with an EC50 of 68.2 μg/mL for DPPH• and 22.4 μg/mL for ABTS•+. Cytotoxicity and zebrafish embryotoxicity results indicated that BWE-CDs have lower cytotoxicity and better biocompatibility than that of CDs derived from organic solvents. In addition, BWE-CDs effectively scavenged reactive oxygen species (ROS) in A549 cells, 293T cells, and zebrafish, as well as eliminating inflammation in LPS-stimulated zebrafish. Mechanistic studies showed that the anti-inflammatory effect of BWE-CDs was dependent on the direct reaction of CDs with free radicals, the regulation of NO levels, and the upregulation of the expression of SOD and GPX-4. This work indicates that the antioxidant activity of CDs could be enhanced by using solvent extracts of biomass as precursors, and the obtained BWE-CDs exhibit characteristics of greenness, low toxicity, and excellent antioxidant and anti-inflammatory activities, which suggests the potential promising application of BWE-CDs as an antioxidant nanomedicine for inflammatory therapy. DA - 2023/2/6/ PY - 2023/2/6/ DO - 10.1021/acsbiomaterials.2c01537 VL - 2 SP - SN - 2373-9878 KW - biomass carbon dot KW - free-radical scavenging KW - broccoli KW - anti-inflammation KW - antioxidant ER - TY - JOUR TI - Metastability and Photoelectrochemical Properties of Cu2SnO3 and Cu2-XLiXTiO3: Two Cu(I)-Based Oxides with Delafossite Structures AU - O'Donnell, Shaun AU - Kremer, Reinhard K. AU - Maggard, Paul A. T2 - CHEMISTRY OF MATERIALS AB - Metastable, p-type Cu(I)-based semiconductors were synthesized using cation-exchange reactions between delafossite-type layered precursors and CuCl flux, yielding Cu2SnO3 (I) and Cu2–xLixTiO3 (II, xmin ∼ 0.4). These represent the first reported crystalline semiconductors found in the Cu–Sn–O or Cu–Ti–O chemical systems (and not currently predicted within any materials databases), with their kinetic stabilization requiring a relatively low reaction temperature of ∼475 °C. Both phases crystallize in the monoclinic crystal system in the space group C2/c, exhibiting edge-shared hexagonal “MO3” (M = Sn or Ti) layers that also contain octahedrally coordinated Li(I)/Cu(I) cations. These layers are bridged by linearly coordinated Cu(I) cations. Magnetic susceptibility measurements confirm the +1 oxidation state of the copper cations. The optical band gaps were found to be indirect and to significantly red shift with the Cu(I) content, down to ∼2.31 eV for I and ∼1.46 eV for II. Electronic structure calculations show that the decreased band gaps can be attributed to a higher energy valence band derived from the filled 3d10 orbitals of the Cu(I) cations, which most notably arise from the octahedrally coordinated Cu(I) cations within the layers. Total energy calculations reveal an increasing metastability with respect to decomposition to Cu2O and SnO2 or TiO2 as a result of occupation of the intralayer sites by Cu(I) cations. In both phases, their edge-shared hexagonal layers lead to highly dispersive conduction bands and small electron effective masses of ∼0.51 me for I and ∼0.41 me for II. Polycrystalline films of both were deposited onto fluorine-doped tin oxide slides and exhibited p-type photocurrents under 100 mW cm–2 irradiation in the range of ∼50 to 250 μA cm–2. This study thus reveals new fundamental relationships between the origin of metastability in Cu(I)-oxide semiconductors, i.e., octahedral coordination, and enhanced optical and photoelectrochemical properties. DA - 2023/1/27/ PY - 2023/1/27/ DO - 10.1021/acs.chemmater.2c03563 VL - 1 SP - 1404-1416 SN - 1520-5002 ER - TY - JOUR TI - Phase Competition and Strong SHG Responses of the (Li2MMSe4)-M-II-Se-IV Family: Atom Response Theory Predictions versus Experimental Results AU - Cheng, Xiyue AU - Deng, Shuiquan AU - Yao, Wen-Dong AU - Guo, Sheng-Ping AU - Whangbo, Myung-Hwan AU - Ding, Bohan T2 - CHEMISTRY OF MATERIALS AB - Compounds of diamond-like (DL) structures are one of the important systems in searching for new high-performance infrared nonlinear optical (IR NLO) materials. However, the phase competition of the diverse DL allotropes and the origin of the SHG response at the atom and orbital level for these NLO materials remain an unsolved hot topic. In this work, the atom response theory (ART) combined with the hybrid density functional calculations was applied to explore the NLO properties of the Li2MIIMIVSe4 (MII = Zn, Cd, Hg; MIV = Si, Ge, Sn) family. Twenty-three new promising IR NLO compounds were predicted with a wide range of band gaps (1.79–3.62 eV), high SHG responses (∼0.7 to 2.5 × AGS), moderate birefringences (∼0.04), and possibly high LIDT (laser-induced damage threshold) values. Among them, Li2HgGeSe4 and Li2HgSnSe4 with the Pna21 structure were experimentally confirmed very recently. The phase competition and the order of band gaps of these compounds were explained from the viewpoint of the crystal structure and chemical bonding. Our ART analyses showed that the large NLO coefficients of these selenides arise mainly from the Se-4p orbitals (∼76%) while the anomaly low contribution of Hg is attributed to the tiny d–p covalent interactions. The SHG responses of all structures were rationalized by the deffp vs αsum/(NEg) linear relationship, showing the importance of this relation in designing and synthesizing new NLO materials. DA - 2023/1/24/ PY - 2023/1/24/ DO - 10.1021/acs.chemmater.2c03151 SP - SN - 1520-5002 ER - TY - JOUR TI - Magnetic Resonance in Molecular Biology, Biophysics and Biochemistry AU - Smirnov, Alex I. I. AU - Kokorin, Alexander I. I. AU - Kovaleva, Elena G. G. T2 - APPLIED MAGNETIC RESONANCE DA - 2023/2/11/ PY - 2023/2/11/ DO - 10.1007/s00723-023-01527-w VL - 2 SP - SN - 1613-7507 ER - TY - JOUR TI - Excited state processes of dinuclear Pt(II) complexes bridged by 8-hydroxyquinoline AU - Kromer, Sarah AU - Roy, Subhangi AU - Yarnell, James E. AU - Taliaferro, Chelsea M. AU - Castellano, Felix N. T2 - DALTON TRANSACTIONS AB - Two novel dinuclear Pt( ii ) complexes featuring 8-hydroxyquinoline bridges were synthesized and found to have photophysical properties dominated by ligand-centered transitions mirroring that of a mononuclear model system, [Pt(8HQ) 2 ]. DA - 2023/3/1/ PY - 2023/3/1/ DO - 10.1039/D3DT00348E VL - 3 SP - SN - 1477-9234 UR - https://doi.org/10.1039/D3DT00348E ER - TY - JOUR TI - Reversible transformations between the non-porous phases of a flexible coordination network enabled by transient porosity AU - Nikolayenko, Varvara I. AU - Castell, Dominic C. AU - Sensharma, Debobroto AU - Shivanna, Mohana AU - Loots, Leigh AU - Forrest, Katherine A. AU - Solanilla-Salinas, Carlos J. AU - Otake, Ken-ichi AU - Kitagawa, Susumu AU - Barbour, Leonard J. AU - Space, Brian AU - Zaworotko, Michael J. T2 - NATURE CHEMISTRY AB - Flexible metal-organic materials that exhibit stimulus-responsive switching between closed (non-porous) and open (porous) structures induced by gas molecules are of potential utility in gas storage and separation. Such behaviour is currently limited to a few dozen physisorbents that typically switch through a breathing mechanism requiring structural contortions. Here we show a clathrate (non-porous) coordination network that undergoes gas-induced switching between multiple non-porous phases through transient porosity, which involves the diffusion of guests between discrete voids through intra-network distortions. This material is synthesized as a clathrate phase with solvent-filled cavities; evacuation affords a single-crystal to single-crystal transformation to a phase with smaller cavities. At 298 K, carbon dioxide, acetylene, ethylene and ethane induce reversible switching between guest-free and gas-loaded clathrate phases. For carbon dioxide and acetylene at cryogenic temperatures, phases showing progressively higher loadings were observed and characterized using in situ X-ray diffraction, and the mechanism of diffusion was computationally elucidated. DA - 2023/2/13/ PY - 2023/2/13/ DO - 10.1038/s41557-022-01128-3 VL - 2 SP - SN - 1755-4349 UR - https://doi.org/10.1038/s41557-022-01128-3 ER - TY - JOUR TI - Substituent-Dependent Azide Addition to Isocyanides Generates Strongly Luminescent Iridium Complexes AU - Jiang, Chenggang AU - Cañada, Louise M. AU - Nguyen, Ngoc Bao AU - Halamicek, Michael D. S. AU - Nguyen, Sami H. AU - Teets, Thomas S. T2 - Journal of the American Chemical Society AB - Ligand-centered functionalization reactions offer diverse strategies to prepare luminescent organometallic compounds. These compounds can have unique structures that are not accessible via traditional coordination chemistry and can possess enhanced or unusual photophysical properties. Here we show that bis-cyclometalated iridium bis-isocyanide complexes (1) react with azide (N3–) to form novel luminescent structures. The fate of the reaction with azide is determined primarily by the substituent on the aryl isocyanide. Those with electron-withdrawing substituents (CF3 or NO2) react with 1 equiv of azide followed by N2 extrusion, forming aryl cyanamido products (2). With electron-donating groups on the aryl isocyanide the reactivity is more diverse, and three outcomes are possible. In two cases, the isocyanide and azide undergo a [3 + 2] cycloaddition to form a C-bound tetrazolato structure (3). In three other cases, 2 equiv of azide are involved in the formation of a previously unobserved structure, where a tetrazolato and aryl cyanamido couple and rearrange to form a chelating ligand comprised of an N-bound tetrazolato and an acyclic diaminocarbene (4). Finally, a bimetallic aryl cyanamido complex (5) is isolated in one case. All compounds are luminescent, some with exceptional photoluminescence quantum yields as high as 0.81 in solution for sky-blue emission, and 0.87 for yellow emission and 0.65 for orange-red emission in polymer films. DA - 2023/1/18/ PY - 2023/1/18/ DO - 10.1021/jacs.2c11062 VL - 145 IS - 2 SP - 1227-1235 UR - http://dx.doi.org/10.1021/jacs.2c11062 ER - TY - JOUR TI - Digital Database of Absorption Spectra of Diverse Flavonoids Enables Structural Comparisons and Quantitative Evaluations AU - Taniguchi, Masahiko AU - LaRocca, Connor A. AU - Bernat, Jake D. AU - Lindsey, Jonathan S. T2 - JOURNAL OF NATURAL PRODUCTS AB - Flavonoids play diverse roles in plants, comprise a non-negligible fraction of net primary photosynthetic production, and impart beneficial effects in human health from a plant-based diet. Absorption spectroscopy is an essential tool for quantitation of flavonoids isolated from complex plant extracts. The absorption spectra of flavonoids typically consist of two major bands, band I (300–380 nm) and band II (240–295 nm), where the former engenders a yellow color; in some flavonoids the absorption tails to 400–450 nm. The absorption spectra of 177 flavonoids and analogues of natural or synthetic origin have been assembled, including molar absorption coefficients (109 from the literature, 68 measured here). The spectral data are in digital form and can be viewed and accessed at http://www.photochemcad.com. The database enables comparison of the absorption spectral features of 12 distinct types of flavonoids including flavan-3-ols (e.g., catechin, epigallocatechin), flavanones (e.g., hesperidin, naringin), 3-hydroxyflavanones (e.g., taxifolin, silybin), isoflavones (e.g., daidzein, genistein), flavones (e.g., diosmin, luteolin), and flavonols (e.g., fisetin, myricetin). The structural features that give rise to shifts in wavelength and intensity are delineated. The availability of digital absorption spectra for diverse flavonoids facilitates analysis and quantitation of these valuable plant secondary metabolites. Four examples are provided of calculations─multicomponent analysis, solar ultraviolet photoprotection, sun protection factor (SPF), and Förster resonance energy transfer (FRET)─for which the spectra and accompanying molar absorption coefficients are sine qua non. DA - 2023/4/28/ PY - 2023/4/28/ DO - 10.1021/acs.jnatprod.2c00720 VL - 86 IS - 4 SP - 1087-1119 SN - 1520-6025 UR - https://doi.org/10.1021/acs.jnatprod.2c00720 ER - TY - JOUR TI - Suppressing Hydrogen Evolution in Aqueous Lithium-Ion Batteries with Double-Site Hydrogen Bonding AU - Guha, Rishabh D. AU - Danilov, Evgeny O. AU - Berkowitz, Katherine AU - Oluwajire, Oluwatimilehin AU - Grace, Landon R. T2 - ACS APPLIED POLYMER MATERIALS DA - 2023/1/13/ PY - 2023/1/13/ DO - 10.1021/acsapm.2c01570400 VL - 5 IS - 1 SP - 400-411 SN - 2637-6105 KW - epoxy KW - moisture KW - humidity KW - infrared spectroscopy KW - dielectric properties ER - TY - JOUR TI - Isocyanide Ligands Promote Ligand-to-Metal Charge Transfer Excited States in a Rhenium(II) Complex AU - Rodriguez, Tayliz M. AU - Deegbey, Mawuli AU - Chen, Chun-Hsing AU - Jakubikova, Elena AU - Dempsey, Jillian L. T2 - INORGANIC CHEMISTRY AB - A metal-to-ligand charge transfer with mixed intraligand character is observed for the rhenium hexakisarylisocyanide complex [Re(CNAr)6]PF6 (CNAr = 2,6-dimethylphenylisocyanide, λmax = 300 nm). Upon oxidation to [Re(CNAr)6](PF6)2, the dominant low energy optical transition is a ligand-to-metal charge transfer (LMCT) mixed with intraligand transitions (λmax = 650 nm). TD-DFT was used to identify the participating ligand-based orbitals in the LMCT transition, revealing that the majority of the donor orbital is based on the aryl ring (85%) as opposed to the CN bond (14%). For both [Re(CNAr)6]+ and [Re(CNAr)6]2+, structural characterization by X-ray diffraction reveals deviations from Oh geometry at the central Re ion, with larger reduction in symmetry observed for Re(II). For [Re(CNAr)6]+, these structural changes lead to a broadening of the strong ν(C≡N) stretch (2065 cm-1), as the degeneracy of the T1u IR-active mode is broken. Furthermore, a shoulder is observed for this ν(C≡N) stretch, resulting from deviation of the C-N-Ar bond from linearity. By contrast, [Re(CNAr)6]2+ has two weak bands in the ν(C≡N) region (2065 and 2121 cm-1). DFT calculations indicate that reduction of symmetry at the central rhenium ion manifests in the decrease in intensity and the observed split of the ν(C≡N) band. Stability of both complexes are limited by light-induced decomposition where Re(I) dissociates a isocyanide ligand upon irradiation and Re(II) absorbance decays under ambient light. These data provide new insights to the electronic structure of [Re(CNAr)6]2+, enhancing our understanding of LMCT excited states and the versatility of isocyanide ligands. DA - 2023/1/18/ PY - 2023/1/18/ DO - 10.1021/acs.inorgchem.2c03193 VL - 1 SP - SN - 1520-510X ER - TY - JOUR TI - Quasi-continuous infrared matrix-assisted laser desorption electrospray ionization source coupled to a quadrupole time-of-flight mass spectrometer for direct analysis from well plates AU - Arciniega, Cristina AU - Garrard, Kenneth P. AU - Guymon, Jacob P. AU - Manni Sr, Jeffrey G. AU - Apffel, Alex AU - Fjeldsted, John C. AU - Muddiman, David C. T2 - JOURNAL OF MASS SPECTROMETRY AB - High-throughput screening (HTS) is a technique mostly used by pharmaceutical companies to rapidly screen multiple libraries of compounds to find drug hits with biological or pharmaceutical activity. Mass spectrometry (MS) has become a popular option for HTS given that it can simultaneously resolve hundreds to thousands of compounds without additional chemical derivatization. For this application, it is convenient to do direct analysis from well plates. Herein, we present the development of an infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) source coupled directly to an Agilent 6545 for direct analysis from well plates. The source is coupled to a quadrupole time-of-flight (Q-TOF) mass spectrometer to take advantage of the high acquisition rates without sacrificing resolving power as required with Orbitrap or Fourier-transform ion cyclotron resonance (FTICR) instruments. The laser used for this source operates at 100 Hz, firing 1 pulse-per-burst, and delivers around 0.7 mJ per pulse. Continuously firing this laser for an extended duration makes it a quasi-continuous ionization source. Additionally, a metal capillary was constructed to extend the inlet of the mass spectrometer, increase desolvation of electrospray charged droplets, improve ion transmission, and increase sensitivity. Its efficiency was compared with the conventional dielectric glass capillary by measured signal and demonstrated that the metal capillary increased ionization efficiency due to its more uniformly distributed temperature gradient. Finally, we present the functionality of the source by analyzing tune mix directly from well plates. This source is a proof of concept for HTS applications using IR-MALDESI coupled to a different MS platform. DA - 2023/1// PY - 2023/1// DO - 10.1002/jms.4902 VL - 58 IS - 1 SP - SN - 1096-9888 KW - ambient ionization KW - direct analysis KW - IR-MALDESI KW - Q-TOF mass spectrometer ER - TY - JOUR TI - Employing Long-Range Inductive Effects to Modulate Metal-to- Ligand Charge Transfer Photoluminescence in Homoleptic Cu(I) Complexes AU - Rosko, Michael C. AU - Espinoza, Eli M. AU - Arteta, Sarah AU - Kromer, Sarah AU - Wheeler, Jonathan P. AU - Castellano, Felix N. T2 - INORGANIC CHEMISTRY AB - Four Cu(I) bis(phenanthroline) photosensitizers formulated from a new ligand structural motif (Cu1–Cu4) coded according to their 2,9-substituents were synthesized, structurally characterized, and fully evaluated using steady-state and time-resolved absorption and photoluminescence (PL) measurements as well as electrochemistry. The 2,9-disubstituted-3,4,7,8-tetramethyl-1,10-phenanthroline ligands feature the following six-membered ring systems prepared through photochemical synthesis: 4,4-dimethylcyclohexyl (1), tetrahydro-2H-pyran-4-yl (2), tetrahydro-2H-thiopyran-4-yl (3), and 4,4-difluorocyclohexyl (4). Universally, these Cu(I) metal-to-ligand charge transfer (MLCT) chromophores display excited-state lifetimes on the microsecond time scale at room temperature, including the three longest-lived homoleptic cuprous phenanthroline excited states measured to date in de-aerated CH2Cl2, τ = 2.5–4.3 μs. This series of molecules also feature high PL quantum efficiencies (ΦPL = 5.3–12% in CH2Cl2). Temperature-dependent PL lifetime experiments confirmed that all these molecules exhibit reverse intersystem crossing and display thermally activated delayed PL from a 1MLCT excited state lying slightly above the 3MLCT state, 1050–1490 cm–1. Ultrafast and conventional transient absorption measurements confirmed that the PL originates from the MLCT excited state, which remains sterically arrested, preventing an excessive flattening distortion even when dissolved in Lewis basic CH3CN. Combined PL and electrochemical data provided evidence that Cu1–Cu4 are highly potent photoreductants (Eox* = −1.73 to −1.62 V vs Fc+/0 in CH3CN), whose potentials are altered solely based on which heteroatoms or substituents are resident on the 2,9-appended ring derivatives. It is proposed that long-range electronic inductive effects are responsible for the systematic modulation observed in the PL spectra, excited-state lifetimes, and the ground state absorption spectra and redox potentials. Cu1–Cu4 quantitatively follow the energy gap law, correlating well with structurally related cuprous phenanthrolines and are also shown to triplet photosensitize the excited states of 9,10-diphenylanthracene with bimolecular rate constants ranging from 1.61 to 2.82 × 108 M–1 s–1. The ability to tailor both photophysical and electrochemical properties using long-range inductive effects imposed by the 2,9-ring platforms advocates new directions for future MLCT chromophore discovery. DA - 2023/2/20/ PY - 2023/2/20/ DO - 10.1021/acs.inorgchem.2c04315 VL - 62 IS - 7 SP - 3248-3259 SN - 1520-510X UR - https://doi.org/10.1021/acs.inorgchem.2c04315 ER - TY - JOUR TI - Expedient synthesis of spiro[3.3]heptan-1-ones via strain-relocating semipinacol rearrangements AU - Jung, Myunggi AU - Muir, Joanna E. AU - Lindsay, Vincent N. G. T2 - TETRAHEDRON AB - A novel approach for the formation of the highly strained spiro[3.3]heptan-1-one motif was developed through the reaction of 1-sulfonylcyclopropanols and lithiated 1-sulfonylbicyclo[1.1.0]butanes. Following initial nucleophilic addition to the cyclopropanone formed in situ, the resulting 1-bicyclobutylcyclopropanol intermediate is prone to a 'strain-relocating' semipinacol rearrangement in the presence of acid, directly affording the substituted spiro[3.3]heptan-1-one. The process is shown to be fully regio- and stereospecific when starting from a substituted cyclopropanone equivalent, leading to optically active 3-substituted spiro[3.3]heptan-1-ones. The reaction likely proceeds via initial protonation of the bicyclobutyl moiety followed by [1,2]-rearrangement of the resulting cyclopropylcarbinyl cation. DA - 2023/3/21/ PY - 2023/3/21/ DO - 10.1016/j.tet.2023.133296 VL - 134 SP - SN - 1464-5416 UR - https://doi.org/10.1016/j.tet.2023.133296 KW - Semipinacol KW - Spiro[3 KW - 3]heptan-1-ones KW - Bicyclobutane KW - Cyclopropanone KW - Strain-release ER - TY - JOUR TI - SABRE Hyperpolarization with up to 200 bar Parahydrogen in Standard and Quickly Removable Solvents AU - Duchowny, Anton AU - Denninger, Johannes AU - Lohmann, Lars AU - Theis, Thomas AU - Lehmkuhl, Soeren AU - Adams, Alina T2 - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES AB - Parahydrogen (p-H2)-based techniques are known to drastically enhance NMR signals but are usually limited by p-H2 supply. This work reports p-H2-based SABRE hyperpolarization at p-H2 pressures of hundreds of bar, far beyond the typical ten bar currently reported in the literature. A recently designed high-pressure setup was utilized to compress p-H2 gas up to 200 bar. The measurements were conducted using a sapphire high-pressure NMR tube and a 43 MHz benchtop NMR spectrometer. In standard methanol solutions, it could be shown that the signal intensities increased with pressure until they eventually reached a plateau. A polarization of about 2%, equal to a molar polarization of 1.2 mmol L-1, could be achieved for the sample with the highest substrate concentration. While the signal plateaued, the H2 solubility increased linearly with pressure from 1 to 200 bar, indicating that p-H2 availability is not the limiting factor in signal enhancement beyond a certain pressure, depending on sample composition. Furthermore, the possibility of using liquefied ethane and compressed CO2 as removable solvents for hyperpolarization was demonstrated. The use of high pressures together with quickly removable organic/non-organic solvents represents an important breakthrough in the field of hyperpolarization, advancing SABRE as a promising tool for materials science, biophysics, and molecular imaging. DA - 2023/2// PY - 2023/2// DO - 10.3390/ijms24032465 VL - 24 IS - 3 SP - SN - 1422-0067 UR - https://doi.org/10.3390/ijms24032465 KW - high-pressure KW - benchtop NMR KW - SABRE KW - hyperpolarization KW - removable solvent ER - TY - JOUR TI - Efficient SABRE-SHEATH Hyperpolarization of Potent Branched-Chain-Amino-Acid Metabolic Probe [1-C-13]ketoisocaproate AU - Adelabu, Isaiah AU - Chowdhury, Md Raduanul H. AU - Nantogma, Shiraz AU - Oladun, Clementinah AU - Ahmed, Firoz AU - Stilgenbauer, Lukas AU - Sadagurski, Marianna AU - Theis, Thomas AU - Goodson, Boyd M. AU - Chekmenev, Eduard Y. T2 - METABOLITES AB - Efficient 13C hyperpolarization of ketoisocaproate is demonstrated in natural isotopic abundance and [1-13C]enriched forms via SABRE-SHEATH (Signal Amplification By Reversible Exchange in SHield Enables Alignment Transfer to Heteronuclei). Parahydrogen, as the source of nuclear spin order, and ketoisocaproate undergo simultaneous chemical exchange with an Ir-IMes-based hexacoordinate complex in CD3OD. SABRE-SHEATH enables spontaneous polarization transfer from parahydrogen-derived hydrides to the 13C nucleus of transiently bound ketoisocaproate. 13C polarization values of up to 18% are achieved at the 1-13C site in 1 min in the liquid state at 30 mM substrate concentration. The efficient polarization build-up becomes possible due to favorable relaxation dynamics. Specifically, the exponential build-up time constant (14.3 ± 0.6 s) is substantially lower than the corresponding polarization decay time constant (22.8 ± 1.2 s) at the optimum polarization transfer field (0.4 microtesla) and temperature (10 °C). The experiments with natural abundance ketoisocaproate revealed polarization level on the 13C-2 site of less than 1%-i.e., one order of magnitude lower than that of the 1-13C site-which is only partially due to more-efficient relaxation dynamics in sub-microtesla fields. We rationalize the overall much lower 13C-2 polarization efficiency in part by less favorable catalyst-binding dynamics of the C-2 site. Pilot SABRE experiments at pH 4.0 (acidified sample) versus pH 6.1 (unaltered sodium [1-13C]ketoisocaproate) reveal substantial modulation of SABRE-SHEATH processes by pH, warranting future systematic pH titration studies of ketoisocaproate, as well as other structurally similar ketocarboxylate motifs including pyruvate and alpha-ketoglutarate, with the overarching goal of maximizing 13C polarization levels in these potent molecular probes. Finally, we also report on the pilot post-mortem use of HP [1-13C]ketoisocaproate in a euthanized mouse, demonstrating that SABRE-hyperpolarized 13C contrast agents hold promise for future metabolic studies. DA - 2023/2// PY - 2023/2// DO - 10.3390/metabo13020200 VL - 13 IS - 2 SP - SN - 2218-1989 UR - https://doi.org/10.3390/metabo13020200 KW - NMR KW - hyperpolarization KW - carbon-13 KW - ketoisocaproate KW - signal amplification by reversible exchange KW - SABRE-SHEATH KW - branched chain amino acid KW - BCAT ER - TY - JOUR TI - Four Routes to 3-(3-Methoxy-1,3-dioxopropyl)pyrrole, a Core Motif of Rings C and E in Photosynthetic Tetrapyrroles AU - Nguyen, Khiem Chau AU - Tran, Anh Thu Nguyen AU - Wang, Pengzhi AU - Zhang, Shaofei AU - Wu, Zhiyuan AU - Taniguchi, Masahiko AU - Lindsey, Jonathan S. T2 - MOLECULES AB - The photosynthetic tetrapyrroles share a common structural feature comprised of a β-ketoester motif embedded in an exocyclic ring (ring E). As part of a total synthesis program aimed at preparing native structures and analogues, 3-(3-methoxy-1,3-dioxopropyl)pyrrole was sought. The pyrrole is a precursor to analogues of ring C and the external framework of ring E. Four routes were developed. Routes 1-3 entail a Pd-mediated coupling process of a 3-iodopyrrole with potassium methyl malonate, whereas route 4 relies on electrophilic substitution of TIPS-pyrrole with methyl malonyl chloride. Together, the four routes afford considerable latitude. A long-term objective is to gain the capacity to create chlorophylls and bacteriochlorophylls and analogues thereof by facile de novo means for diverse studies across the photosynthetic sciences. DA - 2023/2// PY - 2023/2// DO - 10.3390/molecules28031323 VL - 28 IS - 3 SP - SN - 1420-3049 UR - https://doi.org/10.3390/molecules28031323 KW - acylation KW - bacteriochlorophyll KW - beta-ketoester KW - Boc-pyrrole KW - carbonylation KW - chlorophyll KW - synthesis KW - TIPS-pyrrole ER - TY - JOUR TI - Transforming a Mid-infrared Laser Profile from Gaussian to a Top- Hat with a Diffractive Optical Element for Mass Spectrometry Imaging AU - Bai, Hongxia AU - Manni Sr, Jeffrey G. AU - Muddiman, David C. T2 - JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY AB - Many mass spectrometry imaging (MSI) applications such as infrared matrix-assisted electrospray ionization (IR-MALDESI) employ an infrared (IR) laser with a Gaussian profile where laser irradiance is highest in the center and decreases exponentially. To enable full ablation of a square region of interest, oversampling is often needed, which results in nonuniform ablation and leads to decreased image quality. A diffractive optical element (DOE) was integrated into the optical path to generate homogeneous intensity distributions while maintaining laser energy above the ablation threshold, to enable complete sample removal from laser pulses without oversampling. 2D and 3D imaging with the DOE inserted show clear and sharp ablation patterns with satisfactory biological signals gained. Further improvements will optimize the beam profile and generate a square top-hat laser beam for MSI application at higher spatial resolution. DA - 2023/1/4/ PY - 2023/1/4/ DO - 10.1021/jasms.2c00203 VL - 34 IS - 1 SP - 10-16 SN - 1879-1123 KW - diffractive optical element KW - top-hat KW - infrared KW - IR-MALDESI KW - 3D MSI ER - TY - JOUR TI - Dinuclear ligand-to-ligand charge transfer complexes AU - Shultz, David A. A. AU - Stephenson, Riley AU - Kirk, Martin L. L. T2 - DALTON TRANSACTIONS AB - The synthesis and characterization of dinuclear ligand-to-ligand charge transfer complexes are described. Each complex is comprised of square-planar platinum(II) coordinated to a 3-tert-butyl-orthocatecholate donor and a 4,4'-di-tert-butyl-2,2'-bipyridine acceptor. Both complexes exhibit donor → acceptor ligand-to-ligand charge transfer (LL'CT) bands in the visible spectrum. The platinum complexes are covalently attached at the catecholate 5-position to either a meta- or para-phenylene bridge fragment. Both cyclic voltammetry and electronic absorption spectroscopy exhibit features characteristic of intramolecular interaction between the platinum centres. The LL'CT excited state lifetimes are ∼twofold longer than the mononuclear parent complex. The properties of these complexes are discussed and compared to similar complexes in the literature. DA - 2023/1/18/ PY - 2023/1/18/ DO - 10.1039/D2DT03385B VL - 1 SP - SN - 1477-9234 UR - https://doi.org/10.1039/D2DT03385B ER - TY - JOUR TI - Dyads with tunable near-infrared donor-acceptor excited-state energy gaps: molecular design and Forster analysis for ultrafast energy transfer AU - Jing, Haoyu AU - Magdaong, Nikki Cecil M. AU - Diers, James R. AU - Kirmaier, Christine AU - Bocian, David F. AU - Holten, Dewey AU - Lindsey, Jonathan S. T2 - PHYSICAL CHEMISTRY CHEMICAL PHYSICS AB - Bacteriochlorophylls, nature's near-infrared absorbers, play an essential role in energy transfer in photosynthetic antennas and reaction centers. To probe energy-transfer processes akin to those in photosynthetic systems, nine synthetic bacteriochlorin-bacteriochlorin dyads have been prepared wherein the constituent pigments are joined at the meso-positions by a phenylethyne linker. The phenylethyne linker is an unsymmetric auxochrome, which differentially shifts the excited-state energies of the phenyl- or ethynyl-attached bacteriochlorin constituents in the dyad. Molecular designs utilized known effects of macrocycle substituents to engineer bacteriochlorins with S0 → S1 (Qy) transitions spanning 725-788 nm. The design-predicted donor-acceptor excited-state energy gaps in the dyads agree well with those obtained from time dependent density functional theory calculations and with the measured range of 197-1089 cm-1. Similar trends with donor-acceptor excited-state energy gaps are found for (1) the measured ultrafast energy-transfer rates of (0.3-1.7 ps)-1, (2) the spectral overlap integral (J) in Förster energy-transfer theory, and (3) donor-acceptor electronic mixing manifested in the natural transition orbitals for the S0 → S1 transition. Subtle outcomes include the near orthogonal orientation of the π-planes of the bacteriochlorin macrocycles, and the substituent-induced shift in transition-dipole moment from the typical coincidence with the NH-NH axis; the two features together afforded the Förster orientation term κ2 ranging from 0.55-1.53 across the nine dyads, a value supportive of efficient excited-state energy transfer. The molecular design and collective insights on the dyads are valuable for studies relevant to artificial photosynthesis and other processes requiring ultrafast energy transfer. DA - 2023/1/5/ PY - 2023/1/5/ DO - 10.1039/d2cp04689j VL - 1 SP - SN - 1463-9084 UR - https://doi.org/10.1039/D2CP04689J ER - TY - JOUR TI - Investigation of a bacteriochlorin-containing pentad array for panchromatic light-harvesting and charge separation AU - Jing, Haoyu AU - Magdaong, Nikki Cecil M. AU - Diers, James R. AU - Kirmaier, Christine AU - Bocian, David F. AU - Holten, Dewey AU - Lindsey, Jonathan S. T2 - PHYSICAL CHEMISTRY CHEMICAL PHYSICS AB - A crossbar array composed of a panchromatic light-harvesting triad and charge-separation triad has been synthesized and examined in fundamental photophysical studies. DA - 2023/1/4/ PY - 2023/1/4/ DO - 10.1039/d2cp05400k VL - 1 SP - SN - 1463-9084 ER - TY - JOUR TI - A bottom-up proteomics workflow for a system containing multiple organisms AU - Bai, Hongxia AU - Collins, Leonard B. B. AU - Andre, Marcos Rogerio AU - Breitschwerdt, Edward B. B. AU - Williams, Taufika Islam T2 - RAPID COMMUNICATIONS IN MASS SPECTROMETRY AB - Discovery proteomics has been popularized to be essential in the investigator's biological toolbox. Many biological problems involve the interplay of multiple organisms. Herein, a bottom-up proteomics workflow was developed to study a system containing multiple organisms to promote a thorough understanding of how each interacts with the others.A label-free quantification proteomics workflow was developed with nanoscale liquid chromatography coupled to tandem mass spectrometry (nanoLC-MS/MS). This protocol describes a bottom-up proteomics workflow used to study differential protein expression in the context of fleas (Ctenocephalides felis felis) experimentally infected by the bacterium Bartonella henselae, the etiological agent of Cat Scratch Disease (CSD).Step-by-step instructions are provided for protein extraction, protein cleanup, total protein measurement, nanoLC-MS/MS data acquisition, and data analysis using Proteome Discoverer software. Comprehensive and exhaustive details are included to promote the adoption of this proteomics workflow in other laboratories.A proteomics protocol is detailed for a system containing multiple proteomes from different taxonomic lineages using CSD (cats bitten by fleas infected with Bartonella henselae) as a model. The operating protocol can be readily applied to other label-free proteomics work involving multiple proteomes from taxonomically distinct organisms. DA - 2023/1/3/ PY - 2023/1/3/ DO - 10.1002/rcm.9431 VL - 1 SP - SN - 1097-0231 ER - TY - JOUR TI - Oxidation of bisphenol A (BPA) and related compounds by the multifunctional catalytic globin dehaloperoxidase AU - Yun, Dongju AU - Serrano, Vesna AU - Ghiladi, Reza A. T2 - JOURNAL OF INORGANIC BIOCHEMISTRY AB - Dehaloperoxidase (DHP) from the marine polychaete Amphitrite ornata is a multifunctional enzyme that possesses peroxidase, peroxygenase, oxidase and oxygenase activities. Herein, we investigated the reactivity of DHP B with bisphenol A (BPA) and related compounds (bisphenol E, bisphenol F, tetrachlorobisphenol A, 2,2′-biphenol, 3,3′-biphenol, 4,4′-biphenol, and 3,3′-dibromo-4,4′-biphenol). As a previously unknown substrate for DHP B, BPA (as a representative substrate) is an endocrine disruptor widely used in polycarbonate and epoxy resins, thus resulting in human exposure. Reactivity studies with these substrates were investigated using high performance liquid chromatography (HPLC), and their corresponding oxidation products were determined by mass spectrometry (GC–MS/ LC-MS). BPA undergoes oxidation in the presence of DHP B and hydrogen peroxide yielding two cleavage products (4-isopropenylphenol and 4-(2-hydroxypropan-2-yl)phenol), and oligomers with varying degrees of oxidation. 18O-labeling studies confirmed that the O-atom incorporated into the products was derived exclusively from water, consistent with substrate oxidation via a peroxidase-based mechanism. The X-ray crystal structures of DHP bound with bisphenol E (1.48 Å), bisphenol F (1.75 Å), 2,2′-biphenol (1.90 Å) and 3,3′-biphenol (1.30 Å) showed substrate binding sites are in the distal pocket of the heme cofactor, similar to other previously studied DHP substrates. Stopped-flow UV–visible spectroscopy was utilized to investigate the mechanistic details and enzyme oxidation states during substrate turnover, and a reaction mechanism is proposed. The data presented here strongly suggest that DHP B can catalyze the oxidation of bisphenols and biphenols, thus providing evidence of how infaunal invertebrates can contribute to the biotransformation of these marine pollutants. DA - 2023/1// PY - 2023/1// DO - 10.1016/j.jinorgbio.2022.112020 VL - 238 SP - SN - 1873-3344 KW - Bisphenols KW - Biphenols KW - Dehaloperoxidase KW - Hemoglobin KW - Biodegradation KW - Peroxidase ER - TY - JOUR TI - The divergent pH dependence of substrate turnover in dehaloperoxidases A and B AU - Madhuresh, Nikhila Kashyap Dhanvantari AU - Nguyen, Hilbert AU - Franzen, Stefan T2 - JOURNAL OF INORGANIC BIOCHEMISTRY AB - The pH-dependent peroxidase activity in both dehaloperoxidases A and B was studied by a kinetic assay, stopped flow spectroscopy, resonance Raman spectroscopy, and high-performance liquid chromatography at pH 5.0, 6.0, and 7.0. At pH 7.0, both isozymes follow the peroxidase ping-pong kinetic model derived from the three-step reaction scheme using the steady-state approximation. However, deviation from standard saturation behavior is observed at pH < 6.0 and [TCP] > 0.7 mM, owing to multiple processes: a) self-inhibition of TCP by internal binding; b) oxidation of the product by a pH- and concentration-dependent secondary reaction; and c) formation of an inactive species known as compound RH in the absence of oxidizable substrate. Although DHP-A and DHP-B differ by only 5 amino acids, they show a complete trend reversal in their observed peroxidase kinetics and product yields. Although at pH 7.0 DHP-B had higher TCP oxidation activity than DHP-A as reported previously, as pH was lowered, DHP-A appeared to have a higher peroxidase activity than DHP-B. This is an unprecedented result. However, the fact that there are multiple processes contributing to both kinetics and yield of TCP oxidation complicates interpretation of these data. Deactivation via compound RH and self-inhibition are pH dependent reactions that compete with substrate oxidation. Compound RH formation was observed to be rapid at low pH. A complete set of control experiments were conducted to differentiate the various contributions to the observed enzyme kinetics. DA - 2023/1// PY - 2023/1// DO - 10.1016/j.jinorgbio.2022.112029 VL - 238 SP - SN - 1873-3344 KW - Oxidation KW - Mass spectrometry KW - Reaction mechanism KW - Marine KW - Chlorinated molecules KW - Stopped-flow ER - TY - JOUR TI - Origin of Ferromagnetic Exchange Coupling in Donor-Acceptor Biradical Analogues of Charge-Separated Excited States AU - Chen, Ju AU - Yang, Jing AU - Yadav, Munendra AU - Shultz, David A. . AU - Kirk, Martin L. T2 - INORGANIC CHEMISTRY AB - A new donor-acceptor biradical complex, TpCum,MeZn(SQ-VD) (TpCum,MeZn+ = zinc(II) hydro-tris(3-cumenyl-5-methylpyrazolyl)borate complex cation; SQ = orthosemiquinone; VD = oxoverdazyl), which is a ground-state analogue of a charge-separated excited state, has been synthesized and structurally characterized. The magnetic exchange interaction between the S = 1/2 SQ and the S = 1/2 VD within the SQ-VD biradical ligand is observed to be ferromagnetic, with JSQ-VD = +77 cm-1 (H = -2JSQ-VDŜSQ·ŜVD) determined from an analysis of the variable-temperature magnetic susceptibility data. The pairwise biradical exchange interaction in TpCum,MeZn(SQ-VD) can be compared with that of the related donor-acceptor biradical complex TpCum,MeZn(SQ-NN) (NN = nitronyl nitroxide, S = 1/2), where JSQ-NN ≅ +550 cm-1. This represents a dramatic reduction in the biradical exchange by a factor of ∼7, despite the isolobal nature of the VD and NN acceptor radical SOMOs. Computations assessing the magnitude of the exchange were performed using a broken-symmetry density functional theory (DFT) approach. These computations are in good agreement with those computed at the CASSCF NEVPT2 level, which also reveals an S = 1 triplet ground state as observed in the magnetic susceptibility measurements. A combination of electronic absorption spectroscopy and CASSCF computations has been used to elucidate the electronic origin of the large difference in the magnitude of the biradical exchange coupling between TpCum,MeZn(SQ-VD) and TpCum,MeZn(SQ-NN). A Valence Bond Configuration Interaction (VBCI) model was previously employed to highlight the importance of mixing an SQSOMO → NNLUMO charge transfer configuration into the electronic ground state to facilitate the stabilization of the high-spin triplet (S = 1) ground state in TpCum,MeZn(SQ-NN). Here, CASSCF computations confirm the importance of mixing the pendant radical (e.g., VD, NN) LUMO (VDLUMO and NNLUMO) with the SOMO of the SQ radical (SQSOMO) for stabilizing the triplet, in addition to spin polarization and charge transfer contributions to the exchange. An important electronic structure difference between TpCum,MeZn(SQ-VD) and TpCum,MeZn(SQ-NN), which leads to their different exchange couplings, is the reduced admixture of excited states that promote ferromagnetic exchange into the TpCum,MeZn(SQ-VD) ground state, and the intrinsically weaker mixing between the VDLUMO and the SQSOMO compared to that observed for TpCum,MeZn(SQ-NN), where this orbital mixing is significant. The results of this comparative study contribute to a greater understanding of biradical exchange interactions, which are important to our understanding of excited-state singlet-triplet energy gaps, electron delocalization, and the generation of electron spin polarization in both the ground and excited states of (bpy)Pt(CAT-radical) complexes. DA - 2023/1/4/ PY - 2023/1/4/ DO - 10.1021/acs.inorgchem.2c02903 VL - 1 SP - SN - 1520-510X UR - https://doi.org/10.1021/acs.inorgchem.2c02903 ER - TY - JOUR TI - Consequences of Humidity Cycling on the Moisture Absorption Characteristics of Epoxy Resins with Different Network Architectures AU - Guha, Rishabh D. AU - Danilov, Evgeny O. AU - Berkowitz, Katherine AU - Oluwajire, Oluwatimilehin AU - Grace, Landon R. T2 - ACS APPLIED POLYMER MATERIALS AB - Absorbed moisture is a perpetual contributor to the steady loss of performance for in-service epoxy-based polymer materials. On the atomistic scale, the state of individual water molecules in a crosslinked epoxy is dependent on the strength of the secondary bonding interactions they engage in and their local physical environment. However, these chemical and physical variables can be tailored on the macroscopic scale through changes in the experimental curing schedule. In this study, crosslinked epoxy matrices with different network architectures were cured by varying the stoichiometric mixing ratios of the epoxy: hardener combination. The samples were subsequently subjected to fluctuating humidity conditions which comprises repeating cycles of high (∼95% RH) and ambient humidity. Both infrared (IR) spectroscopy and dielectric readings were successful in establishing a strong correlation between moisture absorption, network morphology, and dielectric properties. An anomalous behavior observed during the spectral peak analysis helped us understand how absorption history can redistribute the concentrations of water species at the same moisture concentrations. The results from this study elucidate how the phenomenon of absorption itself can act as a damage initiation event, and they also indicate that the spatial quantification of the different water species across a sample can allow us to map damage sites, nanopores, and areas with an overall higher void content. DA - 2023/1/3/ PY - 2023/1/3/ DO - 10.1021/acsapm.2c01570 VL - 1 SP - SN - 2637-6105 UR - https://doi.org/10.1021/acsapm.2c01570 KW - epoxy KW - moisture KW - humidity KW - infrared spectroscopy KW - dielectric properties ER - TY - JOUR TI - Innentitelbild: Parahydrogen‐Induced Carbon‐13 Radiofrequency Amplification by Stimulated Emission of Radiation (Angew. Chem. 5/2023) AU - Nelson, Christopher AU - Schmidt, Andreas B. AU - Adelabu, Isaiah AU - Nantogma, Shiraz AU - Kiselev, Valerij G. AU - Abdurraheem, Abubakar AU - Maissin, Henri AU - Lehmkuhl, Sören AU - Appelt, Stephan AU - Theis, Thomas AU - Chekmenev, Eduard Y. T2 - Angewandte Chemie AB - Carbon-13 radiofrequency amplification by stimulated emission of radiation (C-13 RASER) is demonstrated on a bolus of liquid hyperpolarized ethyl [1-13C]acetate, as reported by Thomas Theis, Eduard Y. Chekmenev et al. in their Communication (e202215678). Spontaneous RASER signal emissions were detected using a 1.4 T NMR spectrometer equipped with a standard radiofrequency detection coil for over three minutes. RASER detection enables new detection schemes for 13C-hyperpolarized contrast agents and particular new opportunities for next-generation molecular imaging on clinical MRI scanners. DA - 2023/1/26/ PY - 2023/1/26/ DO - 10.1002/ange.202218484 UR - https://doi.org/10.1002/ange.202218484 ER - TY - JOUR TI - Inside Cover: Parahydrogen‐Induced Carbon‐13 Radiofrequency Amplification by Stimulated Emission of Radiation (Angew. Chem. Int. Ed. 5/2023) AU - Nelson, Christopher AU - Schmidt, Andreas B. AU - Adelabu, Isaiah AU - Nantogma, Shiraz AU - Kiselev, Valerij G. AU - Abdurraheem, Abubakar AU - Maissin, Henri AU - Lehmkuhl, Sören AU - Appelt, Stephan AU - Theis, Thomas AU - Chekmenev, Eduard Y. T2 - Angewandte Chemie International Edition AB - Carbon-13 radiofrequency amplification by stimulated emission of radiation (C-13 RASER) is demonstrated on a bolus of liquid hyperpolarized ethyl [1-13C]acetate, as reported by Thomas Theis, Eduard Y. Chekmenev et al. in their Communication (e202215678). Spontaneous RASER signal emissions were detected using a 1.4 T NMR spectrometer equipped with a standard radiofrequency detection coil for over three minutes. RASER detection enables new detection schemes for 13C-hyperpolarized contrast agents and particular new opportunities for next-generation molecular imaging on clinical MRI scanners. DA - 2023/1/26/ PY - 2023/1/26/ DO - 10.1002/anie.202218484 UR - https://doi.org/10.1002/anie.202218484 ER - TY - JOUR TI - Parahydrogen‐Induced Carbon‐13 Radiofrequency Amplification by Stimulated Emission of Radiation AU - Nelson, Christopher AU - Schmidt, Andreas B. AU - Adelabu, Isaiah AU - Nantogma, Shiraz AU - Kiselev, Valerij G. AU - Abdurraheem, Abubakar AU - Maissin, Henri AU - Lehmkuhl, Sören AU - Appelt, Stephan AU - Theis, Thomas AU - Chekmenev, Eduard Y. T2 - Angewandte Chemie International Edition AB - The feasibility of Carbon-13 Radiofrequency (RF) Amplification by Stimulated Emission of Radiation (C-13 RASER) is demonstrated on a bolus of liquid hyperpolarized ethyl [1-13 C]acetate. Hyperpolarized ethyl [1-13 C]acetate was prepared via pairwise addition of parahydrogen to vinyl [1-13 C]acetate and polarization transfer from nascent parahydrogen-derived protons to the carbon-13 nucleus via magnetic field cycling yielding C-13 nuclear spin polarization of approximately 6 %. RASER signals were detected from samples with concentration ranging from 0.12 to 1 M concentration using a non-cryogenic 1.4T NMR spectrometer equipped with a radio-frequency detection coil with a quality factor (Q) of 32 without any modifications. C-13 RASER signals were observed for several minutes on a single bolus of hyperpolarized substrate to achieve 21 mHz NMR linewidths. The feasibility of creating long-lasting C-13 RASER on biomolecular carriers opens a wide range of new opportunities for the rapidly expanding field of C-13 magnetic resonance hyperpolarization. DA - 2023/1/26/ PY - 2023/1/26/ DO - 10.1002/anie.202215678 VL - 62 IS - 5 UR - https://doi.org/10.1002/anie.202215678 KW - Carbon-13 KW - Hyperpolarization KW - NMR Spectroscopy KW - Parahydrogen KW - RASER ER - TY - JOUR TI - Parahydrogen‐Induced Carbon‐13 Radiofrequency Amplification by Stimulated Emission of Radiation AU - Nelson, Christopher AU - Schmidt, Andreas B. AU - Adelabu, Isaiah AU - Nantogma, Shiraz AU - Kiselev, Valerij G. AU - Abdurraheem, Abubakar AU - Maissin, Henri AU - Lehmkuhl, Sören AU - Appelt, Stephan AU - Theis, Thomas AU - Chekmenev, Eduard Y. T2 - Angewandte Chemie AB - Abstract The feasibility of Carbon‐13 Radiofrequency (RF) Amplification by Stimulated Emission of Radiation (C‐13 RASER) is demonstrated on a bolus of liquid hyperpolarized ethyl [1‐ 13 C]acetate. Hyperpolarized ethyl [1‐ 13 C]acetate was prepared via pairwise addition of parahydrogen to vinyl [1‐ 13 C]acetate and polarization transfer from nascent parahydrogen‐derived protons to the carbon‐13 nucleus via magnetic field cycling yielding C‐13 nuclear spin polarization of approximately 6 %. RASER signals were detected from samples with concentration ranging from 0.12 to 1 M concentration using a non‐cryogenic 1.4T NMR spectrometer equipped with a radio‐frequency detection coil with a quality factor ( Q ) of 32 without any modifications. C‐13 RASER signals were observed for several minutes on a single bolus of hyperpolarized substrate to achieve 21 mHz NMR linewidths. The feasibility of creating long‐lasting C‐13 RASER on biomolecular carriers opens a wide range of new opportunities for the rapidly expanding field of C‐13 magnetic resonance hyperpolarization. DA - 2023/1/26/ PY - 2023/1/26/ DO - 10.1002/ange.202215678 UR - https://doi.org/10.1002/ange.202215678 ER -