title: Zinc complexes of the antibacterial drug oxolinic acid: structure and DNA-binding properties.
abstract: The neutral mononuclear zinc complexes with the quinolone antibacterial drug oxolinic acid in the absence or presence of a nitrogen donor heterocyclic ligand 2,2'-bipyridine or 1,10-phenanthroline have been synthesized and characterized. The experimental data suggest that oxolinic acid is on deprotonated mode acting as a bidentate ligand coordinated to the metal ion through the ketone and one carboxylato oxygen atoms. The crystal structures of (chloro)(oxolinato)(2,2'-bipyridine)zinc(II), 2, and bis(oxolinato)(1,10-phenanthroline)zinc(II), 3, have been determined with X-ray crystallography. The biological activity of the complexes has been evaluated by examining their ability to bind to calf-thymus DNA (CT DNA) with UV and fluorescence spectroscopies. UV studies of the interaction of the complexes with DNA have shown that they can bind to CT DNA and the DNA-binding constants have been calculated. Competitive studies with ethidium bromide (EB) have shown that complex 3 exhibits the ability to displace the DNA-bound EB indicating that it binds to DNA in strong competition with EB.
authors.affiliation: Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, P.O. Box 135, GR-54124 Thessaloniki, Greece.
authors.forename: Alketa
authors.initials: A
authors.lastname: Tarushi
authors.forename: George
authors.initials: G
authors.lastname: Psomas
authors.forename: Catherine P
authors.initials: CP
authors.lastname: Raptopoulou
authors.forename: Dimitris P
authors.initials: DP
authors.lastname: Kessissoglou
mesh_terms: D015082:2,2'-Dipyridyl; D000900:Anti-Bacterial Agents / Q000737:chemistry; D001667:Binding, Competitive; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D008024:Ligands; D015394:Molecular Structure; D010093:Oxolinic Acid / Q000737:chemistry*; D010618:Phenanthrolines; D013057:Spectrum Analysis; D015032:Zinc / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D008024:Ligands; D010618:Phenanthrolines; D015082:2,2'-Dipyridyl; D004247:DNA; C427203:calf thymus DNA; D015032:Zinc; D010093:Oxolinic Acid; C025205:1,10-phenanthroline