Synthesis and in vitro Anticancer Activities of Chiral Ruthenium Complexes and Interaction of the complex with Bovine Serum Albumin

Chiral ruthenium(Ⅱ) complexes Δ-[Ru(bpy)2(pyip)]2+ and Λ-[Ru(bpy)2(pyip)]2+ were synthesized and characterized in detail by elemental analysis,1H NMR,electrospray ionization mass spectrometry(ESI-MS) and circular dichroism(CD).The in vitro anticancer activities of the ruthenium(Ⅱ) complexes were screened by MTT assay.The results show that Δ-[Ru(bpy)2(pyip)]2+ exhibited higher cytotoxic effects against human cancer cells.The quenching mechanism of the fluorescence of bovine serum albumin(BSA) by chiral ruthenium(Ⅱ) complexes was investigated by fluorescence spectroscopy under simulative physiological conditions.The binding constant K and the number of binding sites were determined according to Scatchard equation and the main binding force was discussed via thermodynamic equations.The experimental results show that the quenching mechanism of chiral ruthenium(Ⅱ) complexes to bovine serum albumin was static quenching.The binding constants K were 1.16×105,5.12×104,3.64×104 L·mol-1 with one binding site,respectively.The binding force is electrostatic interaction.Chiral ruthenium complexes have nearly no effect on the serum protein conformation.