Synthesis of novel 1,2,5-oxadiazoles and evaluation of action against Acinetobacter baumannii.

With multidrug resistant bacteria on the rise, novel antibiotics are becoming highly sought after. In 2008, eleven compounds were identified by high throughput screening as inhibitors of BasE, a key enzyme of the non-ribosomal peptide synthetase pathway found in Acinetobacter baumannii. Herein, we describe the preparation of four structurally similar heterocyclic lead compounds from that study, including one 1,2,5-oxadiazole. A further library of 30 analogues containing the oxadiazole moiety was then generated. All compounds were screened against Acinetobacter baumannii and their minimum inhibitory concentration data is reported, with (E)-3-(2-hydroxyphenyl)-N-(4-methyl-1,2,5-oxadiazol-3-yl)acrylamide 32 found to have an MIC of 0.5mM. This work provides the foundation for further investigation of 1,2,5-oxadizoles as novel inhibitors of A. baumannii.