DNA interaction and cytotoxic activities of square planar platinum(II) complexes with N, S-donor ligands

Abstract

The platinum(II) complexes with N, S-donor ligands have been synthesized and characterized by physicochemical methods viz. elemental, electronic, FT-IR, (1)H NMR and LC-MS spectra. The binding mode and potency of the complexes with HS DNA (Herring Sperm) have been examined by absorption titration and viscosity measurement studies. The results revealed that complexes bind to HS DNA via covalent mode with the intrinsic binding constant (Kb) in the range 1.37-7.76×10(5)M(-1). Decrease in the relative viscosity of HS DNA also supports the covalent mode of binding. The DNA cleavage activity of synthesized complexes has been carried out by gel electrophoresis experiment using supercoiled form of pUC19 DNA; showing the unwinding of the negatively charged supercoiled DNA. Brine shrimp (Artemia Cysts) lethality bioassay technique has been applied for the determination of toxic property of synthesized complexes in terms of μM.

Keywords: Cytotoxicity; DNA binding; DNA cleavage; N, S-donor ligand; Pt(II) complexes; Unwinding.