Novel 1,3,4-oxadiazoles as antitubercular agents with limited activity against drug-resistant tuberculosis

Aim In recent times, heterocyclic chemotypes are being explored for the development of new antimycobacterials that target the drug-resistant tuberculosis. Here, we are disclosing the 5-substitued 2-mercapto-1,3,4-oxadiazoles as potent antitubercular agents. Methodology A small library of 2-mercapto-1,3,4-oxadiazoles was synthesized using various acids. The compounds were evaluated for antituberculosis activity against M. tuberculosis H37Rv. Results Compound 8j was identified as antitubercular lead with MIC of 0.6 μg/ml against M. tuberculosis H37Rv. This compound was nontoxic to CHO-K1 cells and showed selectivity index of 39. Of note, 8j showed antitubercular activity against pre-extensively drug-resistant clinical isolate of Mycobacterium with MIC of 2 μg/ml. Conclusion This study provides potent antitubercular agent which can be further optimized to discover novel antibiotics.