Butyldithiocarbamate
sodium salt (Bu-dtcNa) and its two complexes, [M(bpy)(Bu-dtc)]NO3 (M=Pt(II) or Pd(II) and bpy=
2,2'-bipyridine), have been synthesized and characterized on the basis of elemental analysis, molar conductivities, IR, 1H NMR, and UV-vis spectra. In these complexes, the dithiocarbamato
ligand coordinates to Pt(II) or Pd(II) center as bidentate with two
sulfur atoms. These complexes show 50% cytotoxic concentration (Cc(50)) values against
chronic myelogenous leukemia cell line, K562, much lower than that of
cisplatin. The interaction of these complexes with
calf thymus DNA was extensively investigated by a variety of spectroscopic techniques. These studies showed that both complexes presumably intercalate in
DNA. UV-vis studies imply that they cooperatively bind with
DNA and unexpectedly denature the
DNA at very low concentrations (approximately 100 microL).
Palladium complex breaks the
DNA into two unequal fragments and binds stronger to the lighter fragment than to the heavier one. In the interaction studies between the Pt(II) and Pd(II) complexes with
DNA, several binding and thermodynamic parameters have been determined, which may provide deeper insights into the mechanism of action of these types of complexes with
nucleic acids.