Characterization and biological properties of copper(II)-ketoprofen complexes

From the reaction of Cu(II) with the non-steroidal anti-inflammatory drug ketoprofen (Hketo), complex [Cu₂(keto)₄(H₂O)₂] was isolated, while the presence of a N,N'-donor heterocyclic ligand 2,2'-bipyridylamine (bipyam), 1,10-phenanthroline (phen) or 2,2'-bipyridine (bipy) led to the formation of complexes of the formula [Cu(keto)₂(N,N'-donor)(H₂O)]. The complexes were characterized by physicochemical and spectroscopic techniques and the crystal structure of [Cu(keto)₂(bipyam)(H₂O)] was determined by X-ray crystallography. The ability of ketoprofen and its complexes to scavenge 1,1-diphenyl-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals was evaluated; the complexes were more active scavengers than free Hketo. The interaction of the complexes with serum albumins was investigated by fluorescence emission spectroscopy and the binding constant of the compounds to the albumins were calculated. Diverse techniques including UV spectroscopy, cyclic voltammetry and viscosity measurements as well as fluorescence emission spectroscopy for the competitive studies of the compounds with ethidium bromide, were employed in our attempt to examine the interaction of the compounds with calf-thymus DNA; as a conclusion, intercalation is the most possible mode of binding.