Synthesis, characterization and DNA-binding studies of a Palladium(II) containing mixed-ligands of 1,10-phenanthroline and salicylic acid complex

The novel antitumor Pd(II) complex of formula [Pd(phen)(SA)] (where, phen=1,10-phenanthroline, SA=Salicylato) from the interaction of molecules [Pd(phen)(H2O)2](NO3)2 and sodium salt of salicylic acid (SA.Na) have been synthesized. The complex has been characterized by conductivity, elemental analysis, UV-Vis, FT-IR and 1H-NMR techniques. The studies indicated that this complex is nonelectrolyte and the salicylato ligand is bidentately bound to Pd(II) ion through two oxygen atoms. The interaction of Pd(II) complex with calf thymus DNA (CT-DNA) was investigated by UV–Vis spectroscopy. This experiment imply the Pd(II) complex interact with DNA. The intrinsic binding constant (Kapp) of interaction between CT-DNA and mentioned complex was obtained 11.25×104 (M-1) 310K, respectively. The concentration of this complex in the midpoint of transition, [L]1/2, at 300K and 310K are 0.011 μM M and 0.015 μM, respectively. This means that the complex can unfold CT-DNA at low concentrations and if this is used as antitumor agent, very low doses will be needed, which may have fewer side effects[1-3].