Mixed-ligand manganese(II)-phenolate complexes: study of DNA cleavage, cytotoxic activity, and induction of apoptosis

Two manganese complexes, [Mn(L-1)(2)(dibe)(2)](L-1) (1) and [Mn(L-2)(2)(dibe)(2)] (2) (where L-1 = 2,2'-bipyridine (bipy), L-2 = 1,10-phenanthroline (phen)), were synthesized by using a carboxylic acid ligand (dibe = 2,2-dibenzylmalonate acid). The two complexes were characterized using IR, elemental analysis, and X-ray crystallography. Fluorescence analysis indicates that the two complexes can bind to HeLa cell DNA (HC-DNA), and gel electrophoresis assay demonstrates the ability of the complexes to cleave the HC-DNA. The two complexes exhibit cytotoxic specificity and significant cancer cell inhibitory rate. Furthermore, apoptotic tests demonstrate that these two complexes have apoptotic effects on HeLa cells.