Synthesis and in-vitro cytotoxicity evaluation of gatifloxacin Mannich bases

Mannich bases of gatifloxacin 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. The compounds were tested in-vitro against a panel of 58 human tumour cell lines derived from nine neoplastic diseases. Among them compound 1-cyclopropyl-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-7[[N4-(3'-sulphadoximino)-1'-(5-bromoisatinyl) methyl]-3-methyl N1-piperazinyl]-3-quinoline carboxylic acid (6) emerged as a potent anticancer agent being more active than standard DNA topoisomerase II inhibitor, etoposide against 30 cancer cell lines.