Synthesis and antitubercular activity of monocyclic nitroimidazoles: insights from econazole

Abstract

We have designed and synthesized econazole-derived nitroimidazoles to investigate the antitubercular activity of the nitroimidazole compounds. The introduction of a nitro group at the 4-position of the imidazole on econazole abolished the antitubercular activity. However, alcoholic nitroimidazoles 4 and 6 compounds were active against Mycobacterium tuberculosis (Mtb). While the MIC value of econazole was 16 μg/mL, the MIC of 6a and 6f turned out to be 0.5 μg/mL. In particular, the activity of 6f against non-replicating Mtb was as good as PA-824, which is currently in clinical phase II studies as an antitubercular agent. Overall, alcohol compounds 4 and 6 tend to be more active than ether compounds 5 and 7.