Effect of carbon chain length on biological activity of novel palladium (II) complexes.

A series of complexes [Pd(L1)(Phen)]·2H2O (1), [Pd(L2)(Phen)]·H2O (2), [Pd(L3)(Phen)]·H2O (3), [Pd(L4)(Phen)]·2H2O (4) and [Pd(L5)(Phen)]·2H2O (5) were prepared. The complexes were characterized by IR, 1H NMR, elemental analysis, and single-crystal X-ray diffractometry. The binding of the complexes was investigated by fluorescence spectrum and UV spectrum, showing the ability of interaction with DNA of intercalative mode. Gel electrophoresis assay demonstrated the ability of the complexes to cleave the pBR322 DNA. Moreover, the five complexes bind to DNA with different binding affinities, in ascending order: complex 1 < 2<3 < 4 < 5. Evaluation of cytotoxic activity of the complexes against five different cancer cell lines proved that the complexes exhibited cytotoxic specificity and significant cancer cell inhibitory rate. [ABSTRACT FROM AUTHOR]