تهيه مشتقات]-N 5-(5-نيتروآريل)-4،3،1- تيادي آزول-2- ايل[ پيپرازينيل كينولون ها و ارزيابي خواص ضد باكتريايي آنها به روش برون تني

Synthesis and In vitro Antibacterial Activity of N-[5-(5-nitroaryl)-1,3,4Thiadiazol- 2-yl] Piperazinyl Quinolones

Background and Objectives: Because resistance to antimicrobial drugs is widespread, recognition of new antimicrobial and understanding of their mechanisms are vital. The quinolones have a broad antibacterial spectrum of activity against Gram-positive, Gram-negative and mycobacterial pathogens such as anaerobes. In the present study, the synthesis and antibacterial activity of a new series of N-piperazinyl quinolones containing 5-(nitroaryl)-I, 3, 4-thiadiazole-2-yl moiety have been studied. Materials and Methods: In this laboratory study, the reaction of l-cyclopropyl-6 fluoro-8 methoxy-4-oxo-7( piperazin-l-yll-l , 4- dihydroquinoline-3- carboxylic acid (compound 3), with 2-chloro-5-(nitroaryl)-1,3,4thiadiazol (compounds 9a-f), in DMF in the presence of NaHC03 at 85-90°C, gave final compounds 1cyclopropyl- 6fluoro-7-[4-[5-(nitroaryl)-1,3, 4-thiadiazol-2yl], piperazin-l-yl] -8- methoxy-4-oxo-quinoline-3carboxylic acid (8a-f). compounds 8a-f, were tested in vitro by the conventional agar dilution method against a panel of microorganisms including stophylococcus aureus, Escherichia coli, salmonella typhi, shigella j1exneri, klebsiella pneumonia, serratia marcescens andpseudomonas aeruginosa. Results: Among synthesized compound, nitrofuran analog 8b exhibited more potent inhibitory activity against Gram-positive bacteria including B. subtilis, S. epidermidis, E. feacalis, M luteus, in respect to other synthesized compounds and reference drug gatifloxacin. Conclusion: Introduction of the bulky group of [5-(5-nitroaryl)-1 ,3,4-thiadiazol-2-yl] could dramatically impact the antibacterial activity of the parent quinolone, and among the nitroaryl groups, 5-nitrofuryl analogue showed the most potent antibacterial activity against the tested microorganisms.