Synthesis of sparfloxacin derivatives as an antibacterial, antimycobacterial agents with cytotoxicity investigation

Based on earlier pieces of evidence of N-piperazinyl fluoroquinolone, and in search of new bioactive molecules from the fluoroquinolone class, the derivates of N-substituted piperazinyl quinolones were synthesized. A series of 2-((amino-1,3,4-thiadiazol-2yl)thio)-1-(4-subst.) (3a-j) were used for diazotization of amines in concentrated hydrochloric acid in the presence of Cu-powder, resulting into 2-((5-chloro-1, 3, 4-thiadiazol-2yl)thio)-1-(4-subst.)ethanone (4a-j). The reaction of (4a-j) with piperazinyl quinolone in dimethylformamide resulted (5a-j). The structure of synthesized compounds was confirmed by their spectral analysis. The compounds are screened against Staphylococcus aureus, Bacillus subtilis(Gram positive)and Escherichia coli, Pseudomonas aeruginosa,(Gram negative) and mycobacterium tuberculosis. The findings revealed moderate activity against Gram-positiveand poorly active against Gram-negative bacteria. Results indicated that halogenated analogs with nitro substitution (5b, 5e, and 5j) derivatives revealed antibacterial and antimycobacterial activity. The results advocate the need for further exploration of such derivatives, coupled with their preclinical and clinical investigation.