Nickel(II) complexes of flufenamic acid: Characterization, structure and interaction with DNA and albumins

Abstract

When NiCl2·6H2O reacts with the non-steroidal anti-inflammatory drug flufenamic acid (Hfluf), complex [Ni(fluf-O)2(MeOH)4], 1 was isolated. When the same reaction takes places in the presence of a N,N′-donor heterocyclic ligand 2,2′-bipyridylamine (bipyam), 2,2′-bipyridine (bipy) and 1,10-phenanthroline (phen), the complexes [Ni(fluf-O,O′)2(bipyam)], 2, [Ni(fluf-O)2(phen)(MeOH)2], 3 and [Ni(fluf-O)2(bipy)(MeOH)2], 4 were isolated, respectively. Complexes 1–4 were characterized by physicochemical and spectroscopic techniques and the crystal structure of complex 2 was determined by X-ray crystallography. The interaction of the complexes with serum albumins was investigated by fluorescence emission spectroscopy and the corresponding binding constants were calculated. UV–Vis spectroscopy, viscosity measurements and fluorescence emission spectroscopy for the competitive studies of the complexes with ethidium bromide were the techniques used in order to investigate the interaction of the complexes with calf-thymus DNA; intercalation was revealed as the most possible mode of DNA-binding.