Synthesis and characterization of a novel Pd(II) complex with the condensation product of 2-(diphenylphosphino)benzaldehyde and ethyl hydrazinoacetate. Cytotoxic activity of the synthesized complex and related Pd(II) and Pt(II) complexes

A new palladium(II) complex I of the condensation product of 2-(diphenylphosphino)benzaldehyde (dpba) and ethyl hydrazinoace-tate (etha) was synthesized and characterized by elemental analyses, IR, and H-1 NMR spectroscopy. The bound ligand is a bidentate (PN chromophore), the remaining two coordination places being occupied by chloride ions in overall square planar geometry. The cytotoxic activity of the complex I and two related Pd(II) and Pt(II) complexes 2 and 3 was tested against a panel of four tumor cell lines. The activity of the complexes was similar to that of cisplatin, the most widely used metal-based antitumor drug. It is important to notice that complexes 2 and 3 were active to cisplatin-resistant U2-OS/Pt cells. Cell cycle alteration investigation, apoptotic assay and gelatin zymography in relation to invasion and metastasis of tumor cells, were performed with all the investigated complexes on Human cervix carcinoma (HeLa) cells. The results suggest that I has a similar effect to cisplatin, inducing apoptosis followed by arrest of cells in S phase of cell cycle, while 2 and 3 induce apoptosis without significant perturbations of cell cycle distribution. (c) 2006 Elsevier Inc. All rights reserved.