Synthesis,spectral characterization and anticancer studies of three novel ruthenium(III) 2,2′‐bipyridine complexes

A series of three new ruthenium(III) bipyridine complexes, [RuCl₃(bipy)L] (L = C₆H₅CHO (Ru1), 4‐CH₃OC₆H₄CHO (Ru2) and 4‐NO₂C₆H₄CHO (Ru3); bipy = 2,2′‐bipyridine), have been synthesized and characterized using microanalysis, magnetic, spectroscopic (IR, UV–visible, electron spin resonance) and cyclic voltammetric techniques. All the ruthenium(III) complexes were found to be stable, paramagnetic and octahedrally coordinated. Electron spin resonance spectra showed an axial symmetry and indicated a tetragonal distortion for the octahedral complexes. All complexes were tested for their cytotoxicities against Ehrlich ascites carcinoma (EAC), superoxide dismutase‐like activities and cytoprotective effects of normal human red blood cells against photo‐irradiation. All the compounds were found to be cytotoxic with half maximal inhibitory concentration (IC₅₀) against EAC at concentrations of 70, 90 and 76 µg for Ru1, Ru2 and Ru3, respectively. Moreover, mean levels of DNA and RNA were significantly elevated in liver tissues of tumorized animals and significantly reduced after treatment of tumorized mice with the complexes. Copyright © 2015 John Wiley & Sons, Ltd.