Synthesis, characterization and anticancer properties of platinum(II) complexes bearing chiral azomethine ligands

Abstract

Pt(II) complexes bearing one N‐salicylidene‐(S)‐1‐phenylethylamine [HL(S)] or N‐salicylidene‐(R)‐1‐phenylethylamine [HL(R)] were synthesized and characterized by electrospray ionization mass spectroscopy (ESI‐MS), Fourier‐transform infrared (FT‐IR), nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopies. The results of the micro‐analytic and spectroscopic methods disclosed that the reaction of K2PtCl4 with the chiral azomethine ligand in DMSO produced both trans‐ and cis‐[Pt(II)L(DMSO)Cl]. Then only trans‐[Pt(II)L(DMSO)Cl] isomers in Na2CO3 solution can transform to Pt(II) complexes 3 in coordination of the ligands to platinum as tridentate C,N,O‐donors. The photophysical properties of obtained platinum(II) complexes were studied by UV‐visible and luminescent spectra. The results showed that they all exhibited emission in the visible region. Anticancer properties in vitro of obtained Pt(II) complexes were scaned for KB and HepG‐2 cancer cell lines. They had good activity for the tested cancer cells. The cis‐Pt(II) complexes possessed higher anticancer activity than trans‐Pt(II) complexes and R‐enantiomers were found to be more cytotoxic than S‐enantiomers.