Investigation of photo-activation on ruthenium(II)-arene complexes for the discovery of potential selective cytotoxic agents

Rational design of ruthenium complexes with optimized ligands is a promising approach to modulate their stability and antiproliferative effects in cancerous cells. The release of ligands from the coordination sphere of the ruthenium complexes can lead to the formation of biologically active Ru species that are able to exert cytotoxic effects. Herein, we have studied this approach on four ruthenium(II) complexes bearing (3,5-cycloheptadienyl)diphenylphosphine or (cycloheptyl)diphenylphosphine and ethylbenzoate or p-cymene and an unusual bimetallic analogue. The stability of the complexes was investigated in DMF as well as DMEM/FBS using H-1 and P-31{H-1} NMR spectroscopy. We studied the photo-cytotoxicities of the complexes in two cell lines - HeLa and RPE-1 - to understand their behavior and cytotoxicity upon ligand dissociation. All complexes showed moderate to high cytotoxicity in the two cell lines upon light irradiation. (C) 2019 Elsevier Ltd. All rights reserved.