Structure-activity relationships of anticancer ruthenium(II) complexes with substituted hydroxyquinolines

• DOI: 10.1016/j.ejmech.2018.04.044
• Publication Date: 2018-04-30T18:44:37Z
• Authors: Dmytro Havrylyuk; Brock S. Howerton; Leona Nease; Sean Parkin; David K. Heidary; Edith C. Glazer
• Keywords: Models, Molecular; Transcription, Genetic; Antineoplastic Agents; Ligands; 01 natural sciences; Ruthenium; 3. Good health; 0104 chemical sciences; Structure-Activity Relationship; Coordination Complexes; Cell Line, Tumor; Neoplasms; Protein Biosynthesis; Hydroxyquinolines; Humans

8-Hydroxyquinolines (HQ), including clioquinol, possess cytotoxic properties and are widely used as ligands for metal-based anticancer drug research. The number and identity of substituents on the HQ can have a profound effect on activity for a variety of inorganic compounds. Ruthenium complexes of HQ exhibit radically improved potencies, and operate by a new, currently unknown, mechanism of action. To define structure-activity relationships (SAR), a family of 22 Ru(II) coordination complexes containing mono-, di- and tri-substituted hydroxyquinoline ligands were synthesized and their biological activity evaluated. The complexes exhibited promising cytotoxic activity against a cancer cell line, and the SAR data revealed the 2- and 7-positions as key sites for the incorporation of halogens to improve potency. The Ru(II) complexes potently inhibited translation, as demonstrated by an in-cell translation assay. The effects were seen at 2-15-fold higher concentrations than those required to observe cytotoxicity, suggesting that prevention of protein synthesis may be a primary, but not the exclusive mechanism for the observed cytotoxic activity.