Synthesis, antibacterial and antitubercular activities of some 7-[4-(5-amino-[1,3,4]thiadiazole-2-sulfonyl)-piperazin-1-yl] fluoroquinolonic derivatives

In the present study, a series of 7-[4-(5-amino-1,3,4 thiadiazole-2-sulfonyl)]-1-piperazinyl fluoroquinolonic derivatives VIIa–d were synthesized in good yields and characterized by IR, 1H-NMR, 13C-NMR, FAB Mass spectral and elemental analyses. The compounds were evaluated for their preliminary in vitro antibacterial activity against some Gram-positive and Gram-negative bacteria and selected compounds VIIa, b were screened for antitubercular activity against Mycobacterium tuberculosis H37Rv strain by broth dilution assay method. The antibacterial data of the tested N-sulfonylfluoroquinolones VIIa–d indicated that all the synthesized compounds showed better activity against Gram-positive bacteria S. aureus, E. faecelis, Bacillus sp. (MIC = 1–5 μg ml–1, respectively) compared to reference drugs. The MIC values of tested derivatives connotes that the sparfloxacin and gatifloxacin derivatives VIIc, d were most active against the tested Gram-positive bacterial strains (MIC = 1–5 μg ml–1). All the tested compounds VIIa–d showed poor activity against the Gram-negative bacteria. The in vitro antitubercular activity reports of selected compounds VIIa, b against M. tuberculosis strain H37Rv showed moderate activity at MIC of 10 μg ml–1.

7-[4-(5-Amino-1,3,4 thiadiazole-2-sulfonyl)]-1-piperazinyl fluoroquinolones (FQs) have been synthesized by the reaction of appropriate N-piperazinyl FQs and 5-acetylamino- [1,3,4]thiadiazole-2-sulfonyl chloride. Compounds tested exhibited pronounced antibacterial activity against the Gram-positive bacteria and moderate–poor activity against Gram-negative bacteria and Mycobacterium tuberculosis strain H37Rv.Figure optionsDownload as PowerPoint slide