Engineering the specificity of antibacterial fluoroquinolones: benzenesulfonamide modifications at C-7 of ciprofloxacin change its primary target in Streptococcus pneumoniae from topoisomerase IV to gyrase.
A series of different N-4-piperazinyl derivatives of norfloxacin was synthesized and screened for their antibacterial, antifungal and cytotoxic activities to monitor the variation in therapeutic effects of parent molecule. Result revealed that some of the tested compounds showed comparable or better activity than norfloxacin against Gram positive bacteria and Gram negative bacteria. The structures of synthetic compounds were determined by using spectroscopic techniques including IR, 1HNMR and EIMS. All the synthetic compounds gave satisfactory elemental analysis.