Structure, DNA Binding Studies and Cytotoxicity of Complex [Pd(phen)(L-asp)]·3H2O

The palladium(II) complex of [Pd(phen)(L‐asp)]·3H2O (phen=1,10‐phenanthroline, H2L‐asp=L‐aspartic acid) has been synthesized from a solution reaction and analyzed by elemental analyses, 1H NMR and IR spectra. Moreover, the complex has been structurally characterized by single‐crystal X‐ray diffractometry. The cytotoxicity assay of the complex and cis‐DDP as reference substance against three different cancer cell lines (Hela, Hep‐G2 and KB) has been conducted. The results show that the Pd complex exhibits higher cytotoxicity against Hela system. The study on the interaction of the Pd complex with fish sperm DNA (FS‐DNA) has been performed with diverse spectroscopic techniques, showing that the complex is bound to the fish sperm DNA via an intercalative mode. Gel electrophoresis assay demonstrates the ability of the complex to cleave the pBR 322 plasmid DNA. In the competitive DNA‐binding experiment, the Pd(II) complex has caused appreciable reduction in the emission intensity, suggesting that the new complex displace DNA‐bound EtBr and bind to DNA at the intercalation sites with almost the same affinity, which is due to partial intercalation of the aromatic ring.