Synthesis and biological properties of a new series of anti-MRSA beta-lactams; 2-(thiazol-2-ylthio)carbapenems.

A series of 1 beta-methylcarbapenems containing variously C-2 substituted thiazol-2-ylthio groups were synthesized, and their in vitro anti-MRSA activity was examined. Among them, 1 beta-methyl-2-(4-arylthiazol-2-ylthio)carbapenems exhibited superior anti-MRSA activity. Introduction of a cationic moiety in the C-2 side chain not only reduced the binding to HSA but also increased the stability against DHP-I, without affecting the anti-MRSA activity. It was also found that the distance between the cationic moiety and the carbapenem skeleton was related to the strength of HSA binding and the stability against DHP-I.