Design, synthesis and evaluation of D,D-peptidase and beta-lactamase inhibitors: azapeptides, oxapeptides and related heterocycles.

Reactive molecules susceptible to form stable acyl enzyme intermediates with D,D-peptidases and beta-lactamases were designed as potential irreversible inhibitors of Penicillin Sensitive Enzymes (PSEs). The structures examined were a series of azapeptides and oxapeptides, both analogs of the D-Ala-D-Ala substrate, and some heterocycles, such as imidazolidinones and oxazolidinones, both analogs of the beta-lactam antibiotics. The various strategies investigated for their synthesis are described and discussed. Some biological results are reported.