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, H-1-NMR, C-13-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 H(37)Rv 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 mu g 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 mu g 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 H(37)Rv showed moderate activity at MIC of 10 mu g ml(-1). (c) 2006 Elsevier SAS. All rights reserved.