Two new palladium(II) complexes: synthesis, characterization and their interaction with HeLa cells.

Two complexes [Pd(L(1))(en)](2)·4H(2)O (1), [Pd(L(2))(en)]·2H(2)O (2), (L(1) = pyridine-2,3-dicarboxylic acid, L(2) = pyrazine-2,3-dicarboxylic acid, and en = ethylenediamine) have been synthesized and characterized using IR, (1)H NMR and element analysis. X-ray analyses of complexes 1 and 2 revealed that 1 belongs to the triclinic system with space group P1(2), and 2 belongs to the monoclinic system with space group P2(1)/n. The binding of the complexes with HC-DNA (HeLa cells DNA, which was extracted by ourselves) were measured by fluorescence spectrum and viscometry. Gel electrophoresis assay demonstrates the ability of the complexes to cleave the extracted HC-DNA. The complexes exhibit a higher cytotoxicity against tumor cells as against normal cells in vitro. Further more, apoptotic tests indicate that the complexes have an apoptotic effect on HeLa cells.