Antibacterial activity of rifamycins for M. smegmatis with comparison of oxidation and binding to tear lipocalin.

ABSTRACT: A mutant of Mycobacterium smegmatis is a potential class I model substitute for Mycobacterium tuberculosis. Because not all of the rifamycins have been tested in this organism, we determined bactericidal profiles for the 6 major rifamycin derivatives. The profiles closely mirrored those established for M. tuberculosis. Rifalazil was confirmed to be the most potent rifamycin. Because the tuberculous granuloma presents a harshly oxidizing environment we explored the effects of oxidation on rifamycins. Mass spectrometry confirmed that three of the six major rifamycins showed autoxidation in the presence of trace metals. Oxidation could be monitored by distinctive changes including isosbestic points in the ultraviolet-visible spectrum. Oxidation of rifamycins abrogated anti-mycobacterial activ

SUBMITTER: Staudinger T 

PROVIDER: S-EPMC3992280 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature