Ru(II)/bisphosphine/diimine/amino acid complexes: diastereoisomerism, cytotoxicity, and inhibition of tumor cell adhesion to collagen type I

Abstract

We herein report the synthesis and characterization of Ru(II)/amino acid complexes with general formula [Ru(AA-H)(dppb)(4-mebipy)](PF6), where AA-H means the deprotonated amino acids Gly, Ala, Val, Met, Trp, Tyr, and Ser; dppb is 1,4-bis(diphenylphosphino)butane and 4-mebipy = 4,4′-dimethyl-2,2′-bipyridine. The complexes were characterized by 31P{1H}, 13C, and 1H NMR spectroscopy, as well as X-ray crystallographic analysis of [Ru(DL-Ala-H)(dppb)(4-mebipy)]+, suggesting the presence of diastereoisomers. The complexes exhibit IC50 values against breast tumor cells (MDA-MB-231) comparable with cisplatin. In addition, the Ru(II)-based complex with tryptophan inhibited tumor cell adhesion to collagen type I. Therefore, the use of ruthenium complexes containing amino acids can be an interesting tool for development of new therapeutic agents.