@article{liu_taniguchi_goel_lindsey_2024, title={Rapid screening of dyes for self-aggregation, adsorption and metabolic integrity - Quantitative metrics as a prelude to biological studies}, volume={223}, ISSN={["1873-3743"]}, url={https://doi.org/10.1016/j.dyepig.2023.111914}, DOI={10.1016/j.dyepig.2023.111914}, abstractNote={The development of dyes for biological applications typically begins with synthesis, is followed by spectroscopic/photophysical characterization, and culminates in testing with cultured cells or in animals. The present work describes a set of facile, low-technology, in vitro, largely quantitative absorption spectrophotometric assays in aqueous solution as a prelude to biological studies. The assays include the following: (1) Self-aggregation in phosphate-buffered saline (PBS), with or without the presence of 3 % bovine serum albumin (BSA), via reciprocal change in concentration and pathlength; (2) Adsorption to solid materials as biomolecular surrogates, including cellulose, chitosan, polyethylene (PE), styrene-divinylbenzene beads (XAD-4), polyacrylic beads (XAD-7), anion exchange beads (IRA-67), cation exchange beads (CG-50), polytetrafluoroethylene (PTFE) membranes, and Nylon membranes; (3) Hydrophilicity/hydrophobicity assessment, by measurement (not calculation) of logP values; and (4) Metabolic integrity, by exposure to a rat liver homogenate. Twenty-two dyes were examined in the assays. The dyes represent diverse classes (acridine, anthraquinone, azo, benzimidazole, coumarin, cyanine, flavonoid, naphthalene, phthalocyanine, polyene, tetrapyrrole, triarylmethine, xanthene), polarity (anionic, cationic, nonionic, hydrophobic, amphipathic), and absorption (ultraviolet, visible, near-infrared). As one example, indocyanine green (ICG), an FDA-approved dye for in vivo use, (i) aggregates at the concentration of 5 μM but disaggregates in the presence of BSA; (ii) in PBS is very adsorptive (>80 % binding) to various materials (cellulose, chitosan, PE, IRA-67, CG-50, PTFE, Nylon) and quite adsorptive (50–80 % binding) to XAD-4 and XAD-7, (iii) exhibits only marginal preference for water versus 1-octanol (1.5:1), and (iv) is largely digested by rat liver homogenate. A single dye can be examined in the span of one day. The quantitative metrics should prove valuable for establishing biologically relevant features of diverse dyes by simple studies in aqueous solution.}, journal={DYES AND PIGMENTS}, author={Liu, Qihui and Taniguchi, Masahiko and Goel, Shreya and Lindsey, Jonathan S.}, year={2024}, month={Apr} }
 @article{son_wu_dou_fujita_cao_liu_lindsey_2023, title={Article Tethered Indoxyl-Glucuronides for Enzymatically Triggered Cross-Linking}, volume={28}, ISSN={["1420-3049"]}, DOI={10.3390/molecules28104143}, abstractNote={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.}, number={10}, journal={MOLECULES}, author={Son, Juno and Wu, Zhiyuan and Dou, Jinghuai and Fujita, Hikaru and Cao, Phuong-Lien Doan and Liu, Qihui and Lindsey, Jonathan S.}, year={2023}, month={May} }
 @misc{nguyen_zhang_liu_zhang_jin_taniguchi_miller_lindsey_2023, title={Tolyporphins-Exotic Tetrapyrrole Pigments in a Cyanobacterium-A Review}, volume={28}, ISSN={["1420-3049"]}, url={https://doi.org/10.3390/molecules28166132}, DOI={10.3390/molecules28166132}, abstractNote={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.}, number={16}, journal={MOLECULES}, author={Nguyen, Kathy-Uyen and Zhang, Yunlong and Liu, Qihui and Zhang, Ran and Jin, Xiaohe and Taniguchi, Masahiko and Miller, Eric S. and Lindsey, Jonathan S.}, year={2023}, month={Aug} }