Cytotoxic activity and structural features of Ru(II)/phosphine/amino acid complexes.
No Thumbnail Available
Date
2018
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Thirteen new ruthenium amino acid complexes were synthesized and characterized. They were obtained by the reaction of α-amino acids (AA) with [RuCl2(P-P)(N-N)], where P-P = 1,4-bis(diphenylphosphino)butane (dppb) or 1,3-bis(diphenylphosphino)propane (dppp) and N-N = 4,4′-dimethyl-2,2′-bipyridine (4′-Mebipy), 5,5′-dimethyl-2,2′-bipyridine (5′-Mebipy) or 4,4′-Methoxy-2-2′-bipyridine (4′-MeObipy). This afforded a family of complexes formulated as [Ru(AA-H)(P-P)(N-N)]PF6, where AA = glycine (Gly), L-alanine (Ala), L-valine (Val), L-tyrosine (Tyr), L-tryptophan (Trp), L-histidine (His) and L-methionine (Met). All compounds were characterized by elemental analysis, spectroscopic and electrochemical techniques. The [Ru(AA-H)(P-P)(N-N)]PF6 complexes are octahedral (the AA-H ligand binding involves N-amine and O-carboxylate), diamagnetic (low-spin d6, S = 0) and present bands due to electronic transitions in the visible region. 1H, 13C{1H} and 31P{1H} NMR spectra of the complexes indicate the presence of C2 symmetry, and the identification of diastereoisomers. In vitro cytotoxicity assays of the compounds and cisplatin were carried out using MDA-MB-231 (human breast) tumor cell line and a non-tumor breast cell line (MCF-10A). Most complexes present promising results with IC50 values comparable with the reference drug cisplatin and high selectivity indexes were found for the complexes containing L-Trp. The binding of two Ru-precursors of the type [RuCl2(dppb)(NN)] (N-N = 4′-MeObipy or 4′-Mebipy) to the blood transporter protein human serum albumin (HSA) was evaluated by fluorescence and circular dichroism spectroscopy. Both complexes bind HSA, probably in the hydrophobic pocket near Trp214, and the Ru-complex containing 4′-MeObipy shows higher affinity for HSA than the 4′-Mebipy one.
Description
Keywords
Ruthenium complexes, Human serum albumin, Circular dichroism
Citation
SANTOS, E. R. dos et al. Cytotoxic activity and structural features of Ru(II)/phosphine/amino acid complexes. Journal of Inorganic Biochemistry, v. 182, p. 48-60, mai. 2018. Disponível em: <https://www.sciencedirect.com/science/article/pii/S016201341730510X>. Acesso em: 05 abr. 2018.