Synthesis, antibacterial, antifungal and anti-HIV evaluation of norfloxacin Mannich bases

Abstract

Mannich bases of norfloxacin were synthesized by reacting them with formaldehyde and several isatin derivatives. Their chemical structures have been confirmed by means of their IR, 1H-NMR data and by elemental analysis. Investigation of antimicrobial activity of compounds was done by agar dilution method against 28 pathogenic bacteria, eight pathogenic fungi and anti-HIV activity against replication of HIV-1 (III B) in MT-4 cells. Among the compounds tested 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7[[N 4-(5'-chloro- 3'-thiosemicarbazono istain-1'-yl) methyl] N 1-piperazinyl] 3-quinoline carboxylic acid showed the most favourable antimicrobial activity.