Novel Cerium(IV) Coordination Compounds of Monensin and Salinomycin.

The largely uncharted complexation chemistry of the veterinary polyether ionophores, monensic and salinomycinic acids (HL) with metal ions of type M 4+ and the known antiproliferative potential of antibiotics has provoked our interest in exploring the coordination processes between MonH/SalH and ions of Ce 4+ . (1) Methods: Novel monensinate and salinomycinate cerium(IV)-based complexes were synthesized and structurally characterized by elemental analysis, a plethora of physicochemical methods, density functional theory, molecular dynamics, and biological assays. (2) Results: The formation of coordination species of a general composition [CeL 2 (OH) 2 ] and [CeL(NO 3 ) 2 (OH)], depending on reaction conditions, was proven both experimentally and theoretically. The metal(IV) complexes [CeL(NO 3 ) 2 (OH)] possess promising cytotoxic activity against the human tumor uterine cervix (HeLa) cell line, being highly selective (non-tumor embryo Lep-3 vs. HeLa) compared to cisplatin, oxaliplatin, and epirubicin.