Synthesis, X-ray crystal structure, DNA/BSA binding, DNA cleavage and cytotoxicity studies of phenanthroline based copper(II)/zinc(II) complexes

Research on copper(II) 1,10-phenanththroline (phen) derivatives continues to attract interest in the context of structure and biological properties. In this paper, two metal complexes [Cu-2(phen)(2)(mu-Cl)(2)]Cl-2 (1), [Zn(phen)(2)(H2O)Cl]Cl center dot 4H(2)O (2) were synthesized and characterized. The crystal structures of 1 and 2 were determined by X-ray diffraction. In order to investigate the biological properties of the prepared complexes, spectroscopic and biological studies were performed. Results of X-ray diffraction showed that 1 and 2 form two types of crystal structures in a given system: dinuclear and mono-nuclear complex. The preliminary study on the DNA cleavage activity has shown that 1 under study behaved as the chemical nucleases. The DNA binding interaction of 1 & 2 with CT-DNA has been investigated by UV-Visible and fluorescence emission spectrometry and the apparent binding constant (K-app) values are 5.1 x 10(4) and 1.2 x 10(4) M-1, respectively. In addition, fluorescence spectrometry of bovine serum albumin (BSA) with 1 & 2 showed that the quenching mechanism might be a static quenching procedure with one binding sites for BSA. In addition, the cytotoxicity of 1 in vitro on tumor cells lines (MCF-7, HepG2 and HT29) was examined by MTT and showed better antitumor effect on the tested cells.