Cytotoxic profile study, DNA and protein binding activity of a new dinuclear nickel(II) thiocyanato complex

Abstract

One new binuclear Ni(II) complex with the molecular formula [Ni2(L)2(SCN)2(μ-SCN)2] (1) has been synthesized using a tridentate Schiff base ligand (L), formed by the condensation between quinoline-2-carboxaldehyde and N,N-dimethylethylenediamine. Complex 1 was characterized by FT-IR, UV-vis, and ESI-mass spectroscopy techniques, as well as elemental analysis, cyclic voltammetry, and single-crystal X-ray crystallography. The X-ray diffraction analysis of 1 indicated a centrosymmetric complex with nickel(II) centers in a distorted octahedral geometry and double bridged by thiocyanate anions via end-to-end (μ-1,3) fashion. The interaction of 1 with CT-DNA was explored by UV-vis and fluorescence spectroscopy, viscosity and cyclic voltammetry which indicated a moderate intercalation of the complex with CT-DNA. The protein binding study of 1 with BSA and HSA was investigated by various spectroscopic methods and indicated a static quenching process. In addition, 1 showed prominent in vitro cytotoxic activity against human melanoma (A375) and human breast carcinoma (MDA-MB-231) cell lines under the identical condition with IC50 value of 149.06 and 124.22 µM, respectively.