Expanding the chemical space of ester of quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives as potential antitubercular agents†

Tuberculosis is a worldwide health problem that warrants attention given that the current treatment options require a long-term chemotherapeutic period and have reported the development of Mycobacterium tuberculosis (M. tuberculosis) multidrug resistant strains. In this study, n-butyl and isobutyl quinoxaline-7-carboxylate 1,4-di-N-oxide were evaluated against replicating and non-replicating H37Rv M. tuberculosis strains. The results showed that seventeen of the twenty-eight derivatives have minimum inhibitory concentration (MIC) values lower than isoniazid (2.92 μM). The most active antimycobacterial agents were T-148, T-149, T-163, and T-164, which have the lowest MIC values (0.53, 0.57, 0.53, and 0.55 μM respectively). These results confirm the potential of quinoxaline-1,4-di-N-oxide against M. tuberculosis to develop and obtain new and more safety antituberculosis drugs.