Design, synthesis, biological evaluation study of spirocyclic POM analogues as novel MmpL3 anti-tubercular agent

We present the development of a phenyl oxazole methyl (POM) core structure with spirocyclic derivatives as part of our efforts to discover innovative anti-tuberculosis agents. Derivatives of spirocyclic POM were synthesized and evaluated for their inhibitory effects on M.tuberculosis (M. tb) H37Rv. Notably, compound 5c displayed potent anti-tubercular activity with MIC value of 0.206 μM in culture broth medium. Furthermore MIC values of compound 5c against DS/MDR/pre-XDR clinical isolates ranged from 0.34 to 0.68 μg/mL, 0.17 to 0.68 μg/mL, and 0.17 to 0.34 μg/mL, respectively. Also, compound 5c with favorable ADME and PK properties was not cytotoxic to THP-1 human cells. Based on the spontaneous mutant generation, we have identified the target of compound 5c to be MmpL3. The computational docking study suggested its plausible binding mode against MmpL3. There is no approved drug targeting this target yet, and the outcomes of the presented research will contribute to the future discovery of novel anti-tuberculosis drugs.