Cysteine Derivatives as Inhibitors for Carboxypeptidase A: Synthesis and Structure−Activity Relationships
摘要:
A series of cysteine (Cys) derivatives having an alkyl or arylalkyl moiety on the a-amino group of the amino acid have been synthesized as a novel type of inhibitor for carboxypeptidase A. These compounds are readily prepared starting with Cys in an optically active form. The structure-activity relationship study revealed that the inhibitors prepared from D-Cys are much more potent than the corresponding inhibitors obtained from L-CYS, and the most potent inhibitor in the series, (S)-1j with a K-i value of 55 +/- 4 nM, is obtained by introducing a phenethyl moiety on the amino group Of D-CyS. In comparison, the most active inhibitor in the series of 2-substituted 3-mercaptopropanoic acid is found to be 20, in which the phenyl ring is linked to the mercaptocarboxylic acid at the a-position with a methylene unit. A proposal that accounts for the different structural requirement for the maximum activity between the two series of inhibitors is provided.
two new C(sp3)−C(sp2) bonds using a bench-stable Ni/bipyridine/Zn system featuring a broad substrate scope and excellent diastereoselectivity, which provides an effective platform for the remote aryl group migration and arylation of amino acid esters via redox-neutral C(sp3)−C(sp2) bond cleavage. Mechanistically, this cascade reaction is accomplished by combining two powerful catalyticcycles consisting