- Peptide-catalyzed conversion of racemic oxazol-5(4 H)-ones into enantiomerically enriched α-amino acid derivatives
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We report the development and optimization of a tetrapeptide that catalyzes the methanolytic dynamic kinetic resolution of oxazol-5(4H)-ones (azlactones) with high levels of enantioinduction. Oxazolones possessing benzylic-type substituents were found to perform better than others, providing methyl ester products in 88:12 to 98:2 er. The mechanism of this peptide-catalyzed process was investigated through truncation studies and competition experiments. High-field NOESY analysis was performed to elucidate the solution-phase structure of the peptide, and we present a plausible model for catalysis.
- Metrano, Anthony J.,Miller, Scott J.
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p. 1542 - 1554
(2014/03/21)
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- Studies on antidiabetic agents. 11. Novel thiazolidinedione derivatives as potent hypoglycemic and hypolipidemic agents
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In the course of further chemical modification of the novel antidiabetic pioglitazone (AD-4833, U-72, 107), a series of 5-[4-(2- or 4- azolylalkoxy)benzyl- or -benzylidene]-2,4-thiazolidinediones was prepared and evaluated for hypoglycemic and hypolipidemic activities in insulin-resistant, genetically obese, and diabetic KKA(y) mice. Replacement of the 2-pyridyl moiety of pioglitazone by a 2- or 4-oxazolyl or a 2- or 4-thiazolyl moiety greatly enhanced in vivo potency. The corresponding 5-benzylidene-type compounds, in which a methine was used as a linker between the benzene ring and the thiazolidinedione ring, also had potent biological activity. Among the compounds synthesized, 5-[4-[2-(5-methyl-2-phenyl-4- oxazolyl)ethoxy]benzyl]-2,4-thiazolidinedione (18) exhibited the most potent activity, more than 100 times that of pioglitazone. The synthesis and structure-activity relationships for this novel series of derivatives are detailed.
- Sohda,Mizuno,Momose,Ikeda,Fujita,Meguro
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p. 2617 - 2626
(2007/10/02)
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- Novel Thiazolidine-2,4-diones as Potent Euglycemic Agents
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A new series of thiazolidine-2,4-diones was obtained by replacing the ether function of englitazone with various functional groups, i.e., a ketone, alcohol, or olefin moiety.These compounds lower blood glucose levels in the genetically obese and insulin-r
- Hulin, Bernard,Clark, David A.,Goldstein, Steven W.,McDermott, Ruth E.,Dambek, Paul J.,et al.
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p. 1853 - 1864
(2007/10/02)
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