A Novel 6-Benzyl Ether Benzoxaborole Is Active against Mycobacterium tuberculosis In Vitro

We identified a novel 6-benzyl ether benzoxaborole with potent activity against Mycobacterium tuberculosis. The compound had an MIC of 2 mu M in liquid medium. The compound was also able to prevent growth on solid medium at 0.8 mu M and was active against intracellular bacteria (50% inhibitory concentration [IC50] = 3.6 mu M) without cytotoxicity against eukaryotic cells (IC50 > 100 mu M). We isolated resistant mutants (MIC >= 100 mu M), which had mutations in Rv1683, Rv3068c, and Rv0047c.