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Joshi H, Paul D, Sathyamoorthi S. Oxidations of Alcohols, Aldehydes, and Diols Using NaBr and Selectfluor. J Org Chem 2023; 88:11240-11252. [PMID: 37490704 PMCID: PMC10804234 DOI: 10.1021/acs.joc.3c01307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
We present protocols for the oxidation of alcohols and aldehydes and for the oxidative cyclization of diols which use a combination of Selectfluor and NaBr. For most substrates, the optimal solvent system is a 1:1 mixture of CH3CN/H2O, but, in select cases, biphasic 1:1 mixtures of EtOAc/H2O or CH2Cl2/H2O are superior. This procedure is operationally simple, uses inexpensive and readily available reagents, and tolerates a variety of functional groups. Mechanistic studies suggest that the active oxidant is hypobromous acid, generated by the almost instantaneous oxidation of Br- by Selectfluor in an aqueous milieu.
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Affiliation(s)
- Harshit Joshi
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
| | - Debobrata Paul
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
| | - Shyam Sathyamoorthi
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
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2
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Wang S, Ma SJ, Lou JC, Sun WW, Wu B. Copper-Catalyzed [3 + 2] Cycloaddition Reaction of N-Hydroxysuccinimide Ester with Isocyanoacetates for the Synthesis of 4,5-Disubstituted Oxazoles. J Org Chem 2023; 88:4481-4493. [PMID: 36918373 DOI: 10.1021/acs.joc.2c03084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
The cycloaddition reaction of N-hydroxysuccinimide ester and isocyanatoacetate catalyzed by copper was described. A series of 4,5-disubstituted oxazole compounds, including ones derived from natural fatty acids, drugs, amino acids, and peptides, were obtained in moderate to high yields. The derivatization reaction was explored. The reaction mechanism was discussed.
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Affiliation(s)
- Shuo Wang
- School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan 430074, China
| | - Shi-Jie Ma
- School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan 430074, China
| | - Ji-Cong Lou
- School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan 430074, China
| | - Wen-Wu Sun
- School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan 430074, China
| | - Bin Wu
- School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan 430074, China.,Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, South-Central Minzu University, Wuhan 430074, China
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3
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Dissanayake AA, Wagner CM, Nair MG. Evaluation of health benefits of sea lamprey (Petromyzon marinus) isolates using in vitro antiinflammatory and antioxidant assays. PLoS One 2021; 16:e0259587. [PMID: 34731213 PMCID: PMC8565778 DOI: 10.1371/journal.pone.0259587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 10/21/2021] [Indexed: 11/18/2022] Open
Abstract
Sea lamprey (Petromyzon marinus), a parasitic fish which survives on blood of other fishes, is consumed as a delicacy in many countries. Our earlier studies on sea lamprey compounds that showed potential to deter adult sea lampreys yielded several sterols, glycerides, free fatty acids, amino acids, organic acids and nitrogenous compounds. Therefore, this study was to assess the health-benefits of these compounds including additional isolates from HPLC fractions that kept aside due to lack of activity in sea lamprey deterrent assays. In vitro cyclooxygenase enzymes (COX-1 and -2) and lipid peroxidation (LPO) inhibitory assays, respectively, were used to determine antiinflammatory and antioxidant activities. Among the tested sterols, cholesteryl eicosapentaenoate and cholesteryl arachidonate exhibited IC50 values of 14.6 and 17.7 μg/mL for COX-1 and 17.3 and 20.8 μg/mL for COX-2, respectively. Cholesteryl palmitate and cholesteryl oleate showed moderate COX-1 and COX-2 enzyme inhibition at 25 μg/mL. Amino acids arginine, tyrosine, glutamic acid, tryptophan and asparagine also showed moderate COX-1 and COX-2 inhibition at the same concentration. Among the twelve new isolates from fractions that we did not investigate earlier, a novel uracil derivative petromyzonacil showed COX-1 and COX-2 inhibition at 25 μg/mL by 35 and 15%, respectively. Cholesterol esters tested at 25 μg/mL exhibited LPO inhibition between 38 and 82 percent. Amino acids cysteine, methionine, aspartic acid, threonine, tryptophan, histidine, glutamic acid, phenylalanine and tyrosine at 25 μg/mL showed LPO inhibition between 37 and 58% and petromyzonacil by 32%. These assay results indicate that consumption of sea lamprey offer health-benefits in addition to nutritional benefits.
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Affiliation(s)
- Amila A. Dissanayake
- Department of Horticulture, Michigan State University, East Lansing, Michigan, United States of America
| | - C. Michael Wagner
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, Michigan, United States of America
| | - Muraleedharan G. Nair
- Department of Horticulture, Michigan State University, East Lansing, Michigan, United States of America
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4
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Gao C, Zhou Q, Yang L, Zhang X, Fan X. Synthesis of α-Amidoketones through the Cascade Reaction of Carboxylic Acids with Vinyl Azides under Catalyst-Free Conditions. J Org Chem 2020; 85:13710-13720. [PMID: 33112628 DOI: 10.1021/acs.joc.0c01871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
An efficient synthesis of α-amidoketone derivatives through the cascade reactions of carboxylic acids with vinyl azides is presented. Compared with literature protocols, notable features of this new method include catalyst-free conditions, broad substrate scope, good tolerance of a wide range of functional groups, and high efficiency. In addition, the synthetic potential of this method as a tool for late-stage modification was convincingly manifested by its application in the structural elaborations of a number of carboxylic acid drug molecules.
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Affiliation(s)
- Cai Gao
- Henan Key Laboratory of Organic Functional Molecules and Drug Innovation, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Qianting Zhou
- Henan Key Laboratory of Organic Functional Molecules and Drug Innovation, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Li Yang
- Henan Key Laboratory of Organic Functional Molecules and Drug Innovation, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Xinying Zhang
- Henan Key Laboratory of Organic Functional Molecules and Drug Innovation, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Xuesen Fan
- Henan Key Laboratory of Organic Functional Molecules and Drug Innovation, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
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5
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Manfrin A, Borduas-Dedekind N, Lau K, McNeill K. Singlet Oxygen Photooxidation of Peptidic Oxazoles and Thiazoles. J Org Chem 2019; 84:2439-2447. [PMID: 30681338 DOI: 10.1021/acs.joc.8b02684] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Oxazoles and thiazoles are commonly found moieties in nonribosomal peptides (NRPs) and ribosomally synthesized post-translationally modified peptides (RiPPs), which are important biomolecules present in the environment and in natural waters. From previous studies, they seem susceptible to oxidation by singlet oxygen (1O2); therefore, we designed and synthesized model oxazole- and thiazole-peptides and measured their 1O2 bimolecular reaction rate constants, showing slow photooxidation under environmental conditions. We reasoned their stability through the electron-withdrawing effect of the carboxamide substituent. Reaction products were elucidated and support a reaction mechanism involving cycloaddition followed by a series of rearrangements. The first 1O2 bimolecular reaction rate constant for a RiPP, the thiazole-containing peptide Aerucyclamide A, was measured and found in good agreement with the model peptide's rate constant, highlighting the potential of using model peptides to study the transformations of other environmentally relevant NRPs and RiPPs.
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Affiliation(s)
- Alessandro Manfrin
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Nadine Borduas-Dedekind
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Kate Lau
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
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Anderson ZJ, Hobson C, Needley R, Song L, Perryman MS, Kerby P, Fox DJ. NMR-based assignment of isoleucine vs. allo-isoleucine stereochemistry. Org Biomol Chem 2018; 15:9372-9378. [PMID: 29090723 DOI: 10.1039/c7ob01995e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple 1H and 13C NMR spectrometric analysis is demonstrated that permits differentiation of isoleucine and allo-isoleucine residues by inspection of the chemical shift and coupling constants of the signals associated with the proton and carbon at the α-stereocentre. This is applied to the estimation of epimerisation during metal-free N-arylation and peptide coupling reactions.
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Affiliation(s)
- Zoe J Anderson
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
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Burkhart BJ, Schwalen CJ, Mann G, Naismith JH, Mitchell DA. YcaO-Dependent Posttranslational Amide Activation: Biosynthesis, Structure, and Function. Chem Rev 2017; 117:5389-5456. [PMID: 28256131 DOI: 10.1021/acs.chemrev.6b00623] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
With advances in sequencing technology, uncharacterized proteins and domains of unknown function (DUFs) are rapidly accumulating in sequence databases and offer an opportunity to discover new protein chemistry and reaction mechanisms. The focus of this review, the formerly enigmatic YcaO superfamily (DUF181), has been found to catalyze a unique phosphorylation of a ribosomal peptide backbone amide upon attack by different nucleophiles. Established nucleophiles are the side chains of Cys, Ser, and Thr which gives rise to azoline/azole biosynthesis in ribosomally synthesized and posttranslationally modified peptide (RiPP) natural products. However, much remains unknown about the potential for YcaO proteins to collaborate with other nucleophiles. Recent work suggests potential in forming thioamides, macroamidines, and possibly additional post-translational modifications. This review covers all knowledge through mid-2016 regarding the biosynthetic gene clusters (BGCs), natural products, functions, mechanisms, and applications of YcaO proteins and outlines likely future research directions for this protein superfamily.
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Affiliation(s)
| | | | - Greg Mann
- Biomedical Science Research Complex, University of St Andrews , BSRC North Haugh, St Andrews KY16 9ST, United Kingdom
| | - James H Naismith
- Biomedical Science Research Complex, University of St Andrews , BSRC North Haugh, St Andrews KY16 9ST, United Kingdom.,State Key Laboratory of Biotherapy, Sichuan University , Sichuan, China
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