A AgOAc/ThioClickFerrophos complex-catalyzed the highly diastereo- and enantioselective reaction between 1-pyrroline-5-carboxylates (1) and acyclic α-enones (2) in MeOH, in the presence of DBU, to give the single isomer Michael adducts (3) in high yields (up to 99%) with excellent enantioselectivies (up to 99% ee). Subsequent reduction of the Michael adducts with sodium cyanoborohydride successfully produced the fused pyrrolizidine ester as an almost pure single stereoisomer.
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http://dx.doi.org/10.1021/acs.joc.7b01335 | DOI Listing |
J Agric Food Chem
January 2025
Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, Liaoning 110016, P. R. China.
Methyleugenol (ME) has been classified as a "group 2B carcinogen" by IARC. Its positional isomer methylisoeugenol (MIE) has been considered to be of "generally recognized as safe'' status by FDA. ME was more cytotoxic than MIE in cultured mouse primary hepatocytes.
View Article and Find Full Text PDFACS Omega
January 2025
Department of Medicine, School of Medicine, Case Western Reserve University, Cardiovascular Research Institute, Cleveland 44106-7078, United States.
We have developed two monoclonal antibodies, CPTC-2MeSC-1 and CPTC-2MeSC-2, against itaconate and its conjugates with sulfhydryl-containing biomolecules such as cysteines. Itaconate is a dicarboxylic acid metabolite that has recently gained much interest for its anti-inflammatory properties in many biological models. We have synthesized an itaconate-cysteine conjugate ITA-Cys designed to mimic in vivo Michael adducts of itaconate.
View Article and Find Full Text PDFACS Chem Biol
January 2025
Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States.
Although methods for Cys-specific bioconjugation and functionalization of proteins have been developed and widely utilized in biomolecule engineering and therapeutic development, reagents for this purpose are generally designed to accomplish bioconjugation only. Consequently, additional clickable groups must be attached to these reagents to accomplish functionalization. Herein, we describe a new, simple, dual-performing bioconjugation-functionalization reagent, VMeTz, which possesses an electron-withdrawing tetrazine (Tz) substituted vinyl (V) moiety to serve as both a Michael receptor for selective conjugation with Cys and a site for click with TCO derivatives to introduce functionality.
View Article and Find Full Text PDFFood Chem
February 2025
Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark. Electronic address:
Polyphenols are well-known for their antioxidant properties, but their prooxidative activity remain less understood. This study quantitatively examined the formation of hydrogen peroxide (HO) during the autooxidation of nine different polyphenols in model systems, investigating how it impacts protein oxidation and protein-polyphenol covalent adduct formation. Polyphenols (4 mM) generated HO in the range of 0.
View Article and Find Full Text PDFFree Radic Res
November 2024
Faculty of Chemistry, Belarusian State University, Minsk, Belarus.
Free radicals are ubiquitous in biological systems, being responsible for pathogenesis of degenerative diseases and participating in vitally important biochemical processes, which are mediated by radical regulatory agents. The effects of the aliphatic amine substituents in the catechol-derived Mannich bases on their antioxidant and pro-oxidant activity were investigated. It has been found that the presence of catechol moiety in the structure of Mannich bases allows them to act as Cu(II) reductants, efficient Fe(II) chelators and potent DPPH radical scavengers.
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