Synthesis of organometallic ruthenium(II) complexes with strong activity against several human cancer cell lines

A new family of “RuCp” (Cp = η5-C5H5) derivatives with bidentate N,O and N,N′-heteroaromatic ligands revealed outstanding cytotoxic properties against several human cell lines namely, A2780, A2780CisR, HT29, MCF7, MDAMB231, and PC3. IC50 values were much lower than those found for cisplatin. Crystal structure of compound 4 was determined by X-ray diffraction studies. Density functional theory (DFT) calculations performed for compound 1 showed electronic flow from the ruthenium center to the coordinated bidentate ligand, in agreement with the electrochemical studies and the existence of a metal-to-ligand charge-transfer (MLCT) band evidenced by spectroscopic data.

Graphical abstractNew “RuCp” derivatives containing bidentate heteroaromatic ligands were fully characterized; outstanding cytotoxicity was found for several human cell lines.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► New family of “RuCp” derivatives containing bidentate heteroaromatic ligands. ► Spectroscopic results showed MLCT band. ► DFT calculations corroborate π backdonation suggested by experimental data. ► Outstanding cytotoxic properties against several human cancer cell lines. ► Reversibility of Ru(II)/Ru(III) shows the interest as bioreductive prodrugs.