Synthesis and antibacterial activity of nitroaryl thiadiazole-gatifloxacin hybrids.

Abstract A number of gatifloxacin analogues containing a nitroaryl-1,3,4-thiadiazole moiety attached to the piperazine ring at C-7 position were prepared and evaluated as antibacterial agents against a panel of Gram-positive and Gram-negative bacteria. Among synthesized compounds, nitrofuran analog 6a exhibited more potent inhibitory activity against Gram-positive bacteria including Staphylococcus epidermidis (MIC = 0.0078 μg/mL), Bacillus subtilis (MIC = 0.0039 μg/mL), Enterococcus faecalis (MIC = 0.125 μg/mL) and Micrococcus luteus (MIC = 0.125 μg/mL), with respect to other synthesized compounds and reference drug gatifloxacin. The target compounds were also assessed for their cytotoxic activity against normal mouse fibroblast (NIH/3T3) cells using MTT assay. The results indicated that these compounds exhibit antibacterial activity at non-cytotoxic concentrations.