title: Biological evaluation of cobalt(II) complexes with non-steroidal anti-inflammatory drug naproxen.
abstract: Cobalt(II) complexes with the non-steroidal anti-inflammatory drug naproxen in the presence or absence of nitrogen-donor heterocyclic ligands (pyridine, 2,2'-bipyridine or 1,10-phenanthroline) have been synthesized and characterized with physicochemical and spectroscopic techniques. The deprotonated naproxen acts as monodentate ligand coordinated to Co(II) ion through a carboxylato oxygen. The crystal structure of [bis(aqua)bis(naproxenato)bis(pyridine)cobalt(II)], 2 has been determined by X-ray crystallography. The EPR spectrum of complex 2 in frozen solution reveals that it retains its structure. UV study of the interaction of the complexes with calf-thymus DNA (CT DNA) has shown that the complexes can bind to CT DNA and [(2,2'-bipyridine)bis(methanol)bis(naproxenato)cobalt(II)] exhibits the highest binding constant to CT DNA. The cyclic voltammograms of the complexes recorded in DMSO solution and in the presence of CT DNA in 1/2 DMSO/buffer (containing 150 mM NaCl and 15 mM trisodium citrate at pH 7.0) solution have shown that they can bind to CT DNA by the intercalative binding mode which has also been verified by DNA solution viscosity measurements. Competitive study with ethidium bromide (EB) has shown that the complexes can displace the DNA-bound EB indicating that they bind to DNA in strong competition with EB. Naproxen and its cobalt(II) complexes exhibit good binding propensity to human or bovine serum albumin proteins having relatively high binding constant values. The antioxidant activity of the compounds has been evaluated indicating their high scavenging activity against hydroxyl free radicals and superoxide radicals.
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: Filitsa
authors.initials: F
authors.lastname: Dimiza
authors.forename: Athanasios N
authors.initials: AN
authors.lastname: Papadopoulos
authors.forename: Vassilis
authors.initials: V
authors.lastname: Tangoulis
authors.forename: Vassilis
authors.initials: V
authors.lastname: Psycharis
authors.forename: Catherine P
authors.initials: CP
authors.lastname: Raptopoulou
authors.forename: Dimitris P
authors.initials: DP
authors.lastname: Kessissoglou
authors.forename: George
authors.initials: G
authors.lastname: Psomas
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry*; D001667:Binding, Competitive; D002417:Cattle; D003035:Cobalt / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry; D004563:Electrochemistry; D016166:Free Radical Scavengers; D006801:Humans; D008958:Models, Molecular; D008968:Molecular Conformation; D009288:Naproxen / Q000737:chemistry*; D011485:Protein Binding; D012709:Serum Albumin / Q000737:chemistry; D014783:Viscosity
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D056831:Coordination Complexes; D016166:Free Radical Scavengers; D012709:Serum Albumin; D003035:Cobalt; D009288:Naproxen; D004247:DNA; C427203:calf thymus DNA