Document Report Card

ID: ALA1137415

Journal: J Med Chem

Title: Structure-activity relationship of 6-methylidene penems bearing 6,5 bicyclic heterocycles as broad-spectrum beta-lactamase inhibitors: evidence for 1,4-thiazepine intermediates with C7 R stereochemistry by computational methods.

Authors: Venkatesan AM, Agarwal A, Abe T, Ushirogochi H, Yamamura I, Ado M, Tsuyoshi T, Dos Santos O, Gu Y, Sum FW, Li Z, Francisco G, Lin YI, Petersen PJ, Yang Y, Kumagai T, Weiss WJ, Shlaes DM, Knox JR, Mansour TS.

Abstract: The design and synthesis of a series of 6-methylidene penems containing [6,5]-fused bicycles (thiophene, imidazole, or pyrazle-fused system) as novel class A, B, and C beta-lactamase inhibitors is described. These penems proved to be potent inhibitors of the TEM-1 (class A) and AmpC (class C) beta-lactamases and less so against the class B metallo-beta-lactamase CcrA. Their in vitro and in vivo activities in combination with piperacillin are discussed. On the basis of the crystallographic structures of a serine-bound reaction intermediate of 2 with SHV-1 (class A) and GC1 (class C) enzymes, compounds 14a-l were designed and synthesized. Penems are proposed to form a seven-membered 1,4 thiazepine ring in both class A and C beta-lactamases. The interaction energy calculation for the enzyme-bound intermediates favor the formation of the C7 R enantiomer over the S enantiomer of the 1,4-thiazepine in both beta-lactamases, which is consistent with those obtained from the crystal structure of 2 with SHV-1 and GC1.

CiteXplore: 16854068

DOI: 10.1021/jm060021p