Anticancer evaluation of ruthenium(III) complexes with N-donor ligands tethered to coumarin or uracil moieties

In this study, the synthesis and characterization of new paramagnetic ruthenium(III) complexes: cis-[RuCl2(urdpa)] (1) {Hurdpa = 6-((bis(pyridin-2-ylmethyl)amino)methyl)uracil} and fac-[RuCl3(chrdpa)] (2) {chrdpa = 4-((bis(pyridin-2-ylmethyl)amino)methyl)-7-methoxycoumarin} are reported. These metal complexes have been comprehensively characterized by an array of physicochemical techniques and the X-ray solid-state structures of 1 and Hurdpa have been attained. Electronic spectroscopy Calf-Thymus DNA titrations revealed that both 1 and 2 are groove binders while molecular docking calculations indicated that the ligands' steric factors dictate the mode of interaction of these individual ruthenium(III) species. These mononuclear ruthenium compounds were screened against cervical and breast cancer cell lines and show activity in the high micromolar range.