Abstract
A mixed-ligand complex, [Cu(Hptc)(Me2bpy)(H2O)]·3H2O (1) (H3ptc = pyridine-2,4,6-tricarboxylic acid; Me2bpy = 4,4′-dimethyl-2,2′-dipyridine), has been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. In the discrete mononuclear structure of 1, the copper core is in a distorted octahedral environment (CuN3O3) derived from tridentate chelate Hptc2−, bidentate chelate Me2bpy and a coordinated water. The interaction of 1 with CT-DNA was investigated by UV–vis spectra, fluorescence spectra and viscosity, which reveals that 1 binds to CT-DNA by partial intercalation. Gel electrophoresis assay demonstrated that the complex displays efficient oxidative cleavage of supercoiled DNA with H2O2 as an oxidant. The in vitro cytotoxicity of 1 on HeLa cells was assessed by MTT and clonogenic assay, where IC50 equals 4.24 ± 0.03 μM. Fluorescence microscopic observations indicated that 1 can induce apoptosis of HeLa cells.
Funding
This study was supported by the National Natural Science Foundation of China [grant number 21371135], [grant number 20971099]; and the Key Program of Tianjin Municipal Natural Science Foundation [grant number 13JCZDJC28200].