1H‐1,2,3‐Triazole tethered isatin‐moxifloxacin: Design, synthesis and in vitro anti‐mycobacterial evaluation

A series of novel 1H‐1,2,3‐triazole tethered isatin–moxifloxacin (MXF) hybrids 5a‐l with greater lipophilicity compared with the parent MXF were designed, synthesized and screened for their in vitro antimycobacterial activities against Mycobacterium tuberculosis (MTB) H37Rv and multidrug‐resistant MTB (MDR–MTB) as well as their cytotoxicity on the VERO cell line. All the synthesized hybrids (MIC: 0.025‐0.78 μg/ml) showed considerable activities against MTB H37Rv and MDR–MTB, and the most active conjugate 5c (MIC: 0.025 and 0.06 μg/ml) was 2 to >2048 times more potent in vitro than the three references MXF (MIC: 0.10 and 0.12 μg/ml), rifampicin (MIC: 0.39 and 32 μg/ml) and isoniazid (MIC: 0.05 and >128 μg/ml) against the two tested strains. All hybrids (CC50: 4‐64 μg/ml) were much more cytotoxic than the parent MXF (CC50: 128 μg/ml), but the most active hybrid 5c (CC50: 32 μg/ml) also displayed acceptable cytotoxicity, warranting further investigation.