Synthesis, characterization and cytotoxicity of mixed-ligand complexes of palladium(II) with aromatic diimine and 4-toluenesulfonyl-L-amino acid dianion.

Eight new palladium(II) complexes (1a-2d) with 4-toluenesulfonyl-l-amino acid dianion and diimine (bipy and phen) have been synthesized and characterized by elemental analysis, IR, UV, (1)H NMR, (13)C NMR and mass spectra techniques. Crystal structure of the complex (2d) has been determined by X-ray diffraction analysis. The cytotoxicity was tested by MTT and SRB assays. The results indicate that the complexes (1a-2d) have selectivity against tested carcinoma cell lines. The complex (2c) has the best cytotoxicity among the eight complexes, moreover its cytotoxicity is better than that of cisplatin against BGC-823, Bel-7402 and KB cell lines. It suggests that both aromatic diimine and 4-toluenesulfonyl-L-amino acid have important effect on cytotoxicity.