DNA Binding and Antitumor Activity of α-Diimineplatinum(II) and Palladium(II) Dithiocarbamate Complexes

The two water-soluble designed platinum(II) complex, [Pt(Oct-dtc)(bpy)]NO(3) (Oct-dtc = Octyldithiocarbamate and bpy = 2,2′ -bipyridine) and palladium(II) complex, [Pd(Oct-dtc)(bpy)]NO(3), have been synthesized and characterized by elemental analyses, molar conductivity measurements, IR, (1)H NMR, and electronic spectra studies. Studies of antitumor activity of these complexes against human cell tumor lines (K562) have been carried out. They show Ic(50) values lower than that of cisplatin. The complexes have been investigated for their interaction with calf thymus DNA (CT-DNA) by utilizing the electronic absorption spectroscopy, fluorescence spectra, and ethidium bromide displacement and gel filtration techniques. Both of these water-soluble complexes bound cooperatively and intercalatively to the CT-DNA at very low concentrations. Several binding and thermodynamic parameters are also described.