@article{nuruzzaman_colella_uzoewulu_meo_gross_ishizawa_sana_zhang_hoff_medlock_et al._2024, title={Hexafluoroisopropanol as a Bioconjugation Medium of Ultrafast, Tryptophan-Selective Catalysis}, volume={2}, ISSN={["1520-5126"]}, DOI={10.1021/jacs.3c13447}, abstractNote={The past decade has seen a remarkable growth in the number of bioconjugation techniques in chemistry, biology, material science, and biomedical fields. A core design element in bioconjugation technology is a chemical reaction that can form a covalent bond between the protein of interest and the labeling reagent. Achieving chemoselective protein bioconjugation in aqueous media is challenging, especially for generally less reactive amino acid residues, such as tryptophan. We present here the development of tryptophan-selective bioconjugation methods through ultrafast Lewis acid-catalyzed reactions in hexafluoroisopropanol (HFIP). Structure-reactivity relationship studies have revealed a combination of thiophene and ethanol moieties to give a suitable labeling reagent for this bioconjugation process, which enables modification of peptides and proteins in an extremely rapid reaction unencumbered by noticeable side reactions. The capability of the labeling method also facilitated radiofluorination application as well as antibody functionalization. Enhancement of an α-helix by HFIP leads to its compatibility with a certain protein, and this report also demonstrates a further stabilization strategy achieved by the addition of an ionic liquid to the HFIP medium. The nonaqueous bioconjugation approaches allow access to numerous chemical reactions that are unavailable in traditional aqueous processes and will further advance the chemistry of proteins.}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Nuruzzaman, Mohammad and Colella, Brandon M. and Uzoewulu, Chiamaka P. and Meo, Alissa E. and Gross, Elizabeth J. and Ishizawa, Seiya and Sana, Sravani and Zhang, He and Hoff, Meredith E. and Medlock, Bryce T. W. and et al.}, year={2024}, month={Feb} }
 @article{ugwu_eze_ezeorah_rhyman_ramasami_tania_eze_uzoewulu_ogboo_okpareke_2023, title={Synthesis, Structure, Hirshfeld Surface Analysis, Non-Covalent Interaction, and In Silico Studies of 4-Hydroxy-1-[(4-Nitrophenyl) Sulfonyl]Pyrrolidine-2-Carboxyllic Acid}, ISSN={["1572-8854"]}, DOI={10.1007/s10870-023-00978-0}, abstractNote={The new compound 4-hydroxy-1-[(4-nitrophenyl)sulfonyl]pyrrolidine-2-carboxyllic acid was obtained by the reaction of 4-hydroxyproline with 4-nitrobenzenesulfonyl chloride. The compound was characterized using single crystal X-ray diffraction studies. Spectroscopic methods including NMR, FTIR, ES-MS, and UV were employed for further structural analysis of the synthesized compound. The title compound was found to have crystallized in an orthorhombic crystal system with space group P212121. The S1-N1 bond length of 1.628 (2) Å was a strong indication of the formation of the title compound. The absence of characteristic downfield 1H NMR peak of pyrrolidine ring and the presence of S-N stretching vibration at 857.82 cm-1 on the FTIR are strong indications for the formation of the sulfonamide. The experimental study was complemented with computations at the B3LYP/6-311G + + (d,p) level of theory to gain more understanding of interactions in the compound at the molecular level. Noncovalent interaction, Hirsfeld surface analysis and interaction energy calculations were employed in the analysis of the supramolecular architecture of the compound. Predicted ADMET parameters, awarded suitable bioavailability credentials, while the molecular docking study indicated that the compound enchants promising inhibition prospects against dihydropteroate synthase, DNA topoisomerase, and SARS-CoV-2 spike.Herein we present the solid state structure, noncovalent interaction and spectroscopic analysis of a prospective bioactive compound 4-hydroxy-1-[(4-nitrophenyl)sulphonyl]pyrrolidine-2-carboxyllic acid.The online version contains supplementary material available at 10.1007/s10870-023-00978-0.}, journal={JOURNAL OF CHEMICAL CRYSTALLOGRAPHY}, author={Ugwu, David Izuchukwu and Eze, Florence Uchenna and Ezeorah, Chigozie Julius and Rhyman, Lydia and Ramasami, Ponnadurai and Tania, Groutso and Eze, Cosmas Chinweike and Uzoewulu, Chiamaka Peace and Ogboo, Blessing Chinweotito and Okpareke, Obinna Chibueze}, year={2023}, month={Mar} }
 @article{hall_uzoewulu_nizam_ishizawa_el-shaffey_ohata_2022, title={Phosphine-mediated three-component bioconjugation of amino- and azidosaccharides in ionic liquids}, volume={8}, ISSN={["1364-548X"]}, url={https://doi.org/10.1039/D2CC04013A}, DOI={10.1039/d2cc04013a}, abstractNote={Bioconjugation of carbohydrates has been a challenging task because of their chemical, functional, and structural diversities, and no single chemical modification tool can be universally applicable to all the target substrates in different environments.}, journal={CHEMICAL COMMUNICATIONS}, publisher={Royal Society of Chemistry (RSC)}, author={Hall, Yvonne D. and Uzoewulu, Chiamaka P. and Nizam, Zeinab M. and Ishizawa, Seiya and El-Shaffey, Hisham M. and Ohata, Jun}, year={2022}, month={Aug} }
 @article{eze_ezeorah_ogboo_okpareke_rhyman_ramasami_okafor_tania_atiga_ejiyi_et al._2022, title={Structure and Computational Studies of New Sulfonamide Compound: {(4-nitrophenyl)sulfonyl}tryptophan}, volume={27}, ISSN={["1420-3049"]}, DOI={10.3390/molecules27217400}, abstractNote={Synthesis of sulfonamide through an indirect method that avoids contamination of the product with no need for purification has been carried out using the indirect process. Here, we report the synthesis of a novel sulfonamide compound, ({4-nitrophenyl}sulfonyl)tryptophan (DNSPA) from 4-nitrobenzenesulphonylchloride and L-tryptophan precursors. The slow evaporation method was used to form single crystals of the named compound from methanolic solution. The compound was characterized by X-ray crystallographic analysis and spectroscopic methods (NMR, IR, mass spectrometry, and UV-vis). The sulfonamide N-H NMR signal at 8.07–8.09 ppm and S-N stretching vibration at 931 cm−1 indicate the formation of the target compound. The compound crystallized in the monoclinic crystal system and P21 space group with four molecules of the compound in the asymmetric unit. Molecular aggregation in the crystal structure revealed a 12-molecule aggregate synthon sustained by O-H⋯O hydrogen bonds and stabilised by N-H⋯O intermolecular contacts. Experimental studies were complemented by DFT calculations at the B3LYP/6-311++G(d,p) level of theory. The computed structural and spectroscopic data are in good agreement with those obtained experimentally. The energies of interactions between the units making up the molecule were calculated. Molecular docking studies showed that DNSPA has a binding energy of −6.37 kcal/mol for E. coli DNA gyrase (5MMN) and −6.35 kcal/mol for COVID-19 main protease (6LU7).}, number={21}, journal={MOLECULES}, author={Eze, Florence Uchenna and Ezeorah, Chigozie Julius and Ogboo, Blessing Chinweotito and Okpareke, Obinna Chibueze and Rhyman, Lydia and Ramasami, Ponnadurai and Okafor, Sunday Nwankwo and Tania, Groutso and Atiga, Simeon and Ejiyi, Thomas Ugochukwu and et al.}, year={2022}, month={Nov} }
 @article{uzoewulu_ohata_2022, title={Translation of a Phosphine- and Azide-Based Reaction to Chemical Modification of Biomolecules in Ionic Liquid}, volume={7}, ISSN={["1437-2096"]}, url={https://doi.org/10.1055/a-1908-2066}, DOI={10.1055/a-1908-2066}, abstractNote={Abstract}, journal={SYNLETT}, publisher={Georg Thieme Verlag KG}, author={Uzoewulu, Chiamaka P. and Ohata, Jun}, year={2022}, month={Aug} }