Bonnett, S. A. | Search bioRxiv

bioRxiv2018

Activation of 2,4-diaminoquinazoline in Mycobacterium tuberculosis by Rv3161c, a putative dioxygenase

The diaminoquinazoline series has good potency against Mycobacterium tuberculosis. Resistant isolates have mutations in Rv3161c, a putative dioxygenase. We carried out metabolite analysis on wild-type and an Rv3161c mutant strain after exposure to a diaminoquinazoline. The parental compound was found in intracellular extracts from the mutant, but not the wild-type. A metabolite consistent with a mono-hydroxylated form was identified in the wild-type. These data support the hypothesis that Rv3161c metabolizes diaminoquinazolines in M. tuberculosis.

microbiology↗

bioRxiv2018

Phenylhydrazones are active against non-replicating Mycobacterium tuberculosis

There is an urgent need for the development of shorter, simpler and more tolerable drugs to treat antibiotic tolerant populations of Mycobacterium tuberculosis. We previously identified a series of phenylhydrazones (PHY) active against M. tuberculosis. We selected six representative compounds for further analysis. All compounds were active against non-replicating M. tuberculosis, with two compounds demonstrating greater activity under hypoxic conditions than aerobic culture. Compounds had bactericidal activity with MBC/MIC of <4 and demonstrated an inoculum-dependent effect against aerobically replicating bacteria. Bacterial kill kinetics demonstrated a faster rate of kill against non-replicating bacilli generated by nutrient starvation. Compounds had limited activity against other bacterial species. In conclusion, we have demonstrated that the PHY compounds have some attractive properties in terms of their anti-tubercular activity.

microbiology↗