Synthesis, characterization, DNA binding and cytotoxicity studies of moxifloxacinato complexes

Five metal complexes of the third-generation quinolone antibacterial agent moxifloxacin with Cu(II), Fe(III), Mn(II), Ni(II) and VO(II) have been synthesized and characterized by physicochemical and spectroscopic techniques. In these complexes, moxifloxacin acts as a bidentate deprotonated ligand bound to the metal through ketone and carboxylate oxygens. The interactions between the metal complexes and calf thymus DNA have been studied by UV?CVis, circular dichroism and cyclic voltammetry. Fluorescence competitive binding studies with ethidium bromide (EB) demonstrate the ability of the complexes to displace the EB bound to DNA. The cytotoxicities of the complexes have been evaluated on A549 cells by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) method. [Cu(MFL)₂(H₂O)₂] shows the highest anticancer potency. The apoptosis-inducing activity was assessed by acridine orange/ethidium bromide staining assay.