Synthesis, characterization and biological activity of Zn coordination compounds with the quinolone gatifloxacin.

Four novel zinc-gatifloxacin complexes exhibit noteworthy antimicrobial activity and bind tightly to albumins and to calf-thymus DNA. Four novel zinc coordination compounds of gatifloxacin (Hgati), a third-generation quinolone, with a N,N′-donor heterocyclic ligand, such as 2,2′-bipyridylamine, 1,10-phenanthroline or 2,2′-bipyridine, were characterized with physicochemical techniques and various spectroscopies. The antimicrobial activity of the compounds against the microorganisms Xanthomonas campestris , Escherichia coli , Bacillus subtilis and Staphylococcus aureus was similar or better than that of free Hgati. The complexes may bind to calf-thymus DNA via intercalation as concluded via a series of studies employing DNA-viscosity measurements, UV–Vis spectroscopy and competition with ethidium bromide. The complexes may bind to albumins in order to get transferred through the bloodstream. [ABSTRACT FROM AUTHOR]