Synthesis and analysis of the anticancer activity of Ru(II) complexes incorporating 2-hydroxy-methylidene-indene-1,3-dione ligands

2-Hydroxymethylidene-indene-1,3-diones bearing alkoxyvinyl, pyrrolyl, and indolyl groups were synthesized by thermal decomposition of the phenyliodonium ylide of lawsone and served as ligands for the preparation of piano-stool Ru(II) complexes. The reactivity of the new compounds with biomolecules and their stability in aqueous solution have been studied. The synthesized complexes have been tested for their anticancer activity against four human ovarian cancer cell lines (OVCAR-5, SKOV-3, UWB1.289, and UWB1.289 + BRCA1) in order to investigate their structure-activity relationships. The ruthenium complexes bearing the dihydrofuryl, the 2-(butoxy) vinyl, and the 2-(isobutoxy) vinyl substituents were the most potent compounds identified in this screen with IC50 values in the range of 22-82 mu M. Complexes 11d, 11a, and 11b were found to be more active than cisplatin against the SKOV3 human ovarian cancer cells.