Abstract: | We report herein the design, synthesis, and antimycobacterial activity of a series of diethylene glycol tethered gatifloxacin–isatin hybrids 5a – o in this paper. Results revealed that all hybrids showed promising activity against both drug‐sensitive and multidrug‐resistant Mycobacterium tuberculosis strains with minimum inhibitory concentration (MIC) in a range of 1–128 μg/mL. Particularly, hybrid 5j with low cytotoxicity in VERO cell line was comparable with the parent gatifloxacin (MIC: 0.78 and 1 μg/mL) against MTB H37Rv and MDR‐TB strains, and ≥32‐fold more potent than isoniazid and rifampicin (MIC: >128 and 32 μg/mL, respectively) against MDR‐TB, suggesting it may serve as a new and promising candidate for further study. |