Copper(II) complexes with non-steroidal anti-inflammatory drugs and neocuproine: Structure and biological evaluation.

• Copper(II) complexes with non-steroidal anti–inflammatory drugs were characterized. • One structure was characterized by single-crystal X-ray crystallography. • The complexes show noteworthy antioxidant activity. • The complexes may bind reversibly to bovine serum albumin. • Intercalation is the interaction mode of complexes with calf-thymus DNA. Four novel copper(II) complexes with the non-steroidal anti-inflammatory drugs tolfenamic acid (Htolf), mefenamic acid (Hmef), naproxen (Hnap) and sodium diclofenac (Na dicl) were prepared in the presence of the N,N '–donor neocuproine (neoc) as co–ligand and were characterized by physicochemical and spectroscopic techniques. The complexes bear the formulas: [Cu(tolf) 2 (neoc)] (complex 1), [Cu(mef) 2 (neoc)] (complex 2), [Cu(nap) 2 (neoc)] (complex 3) and [Cu(dicl) 2 (neoc)] (complex 4), respectively. Single-crystal X-ray crystallography was employed to determine the crystal structure of complex [Cu(tolf) 2 (neoc)]. The in vitro scavenging activity of the complexes against 1,1–diphenyl–picrylhydrazyl and 2,2′–azinobis(3–ethylbenzothiazoline–6–sulfonic acid) free radicals and the ability to reduce H 2 O 2 were studied in the context of the antioxidant activity studies. The compounds interact with calf-thymus DNA via intercalation, as indicated by UV–vis spectroscopy and DNA–viscosity titration studies, and competitive studies with ethidium bromide. Additionally, the complexes were checked for their binding affinity to bovine serum albumin by fluorescence emission spectroscopy, and demonstrated significant and reversible binding to the albumin. [Display omitted] Four copper(II) complexes with non-steroidal anti-inflammatory drugs as ligands and neocuproine as co-ligand were prepared and characterized. The compounds present significant antioxidant activity, interact with calf-thymus DNA via intercalation and can bind tightly and reversibly to bovine serum albumin. [ABSTRACT FROM AUTHOR]