Design, Synthesis and In Vitro Antitubercular Evaluation of Isatin‐ciprofloxacin Hybrids with Hydrogen Bonding Capacity

Abstract

A series of novel isatin‐ciprofloxacin hybrids inhaling oxime, semicarbazone, and thiosemicarbazone groups with hydrogen bonding capacity were designed, synthesized, and evaluated for their in vitro antitubercular activities against Mycobacterium tuberculosis (MTB) H37Rv and multidrug‐resistant‐TB (MDR‐TB). All hybrids endowed with potential activities against the tested MTB H37Rv and MDR‐TB strains with minimum inhibitory concentration (MIC) in a range of 0.20 to 128 μg/mL. In particular, the most active hybrid 5e (MIC: 0.20 and 0.5 μg/mL) was four and two times more active than the parent ciprofloxacin (MIC: 0.78 μg/mL) and rifampicin (MIC: 0.39 μg/mL) against MTB H37Rv, and 4–>256 times more potent than the three references ciprofloxacin (MIC: 2.0 μg/mL), rifampicin (MIC: 32 μg/mL), and isoniazid (>128 μg/mL) against MDR‐TB. Thus, this kind of hybrids holds great promise as future anti‐TB agents against both drug‐sensitive and drug‐resistant MTB strains infection.