Nitrosyl/Diphenylphosphine/Amino Acid-Ruthenium Complexes as Inhibitors of MDA-MB-231 Breast Cancer Cells

Herein, we report on the synthesis and characterization of ruthenium compounds with the general formula [RuCl(AA-H)(NO)(dppb]PF6, where AA = glycine (1), L-alanine (2), L-phenylalanine (3) and L-valine (4), and dppb = 1,4-bis(diphenylphosphine)butane. The complexes were characterized using elemental analysis, UV/Vis and infrared spectroscopies, H-1, C-13, P-31 NMR techniques, and cyclic voltammetry. Furthermore, the structures of the compounds (1) and (3) were determined using single-crystal X-ray diffraction. In vitro evaluation of the Ru(II)/nitrosyl/amino acid complexes revealed their cytotoxic activities against triple-negative MDA-MB-231 breast cancer cells, and against the non-tumor murine fibroblast cells. All the compounds decreased the percentage of viable cells, inducing cell death by apoptosis. Additionally, the Ru(II) complexes inhibited the migration of MDA-MB-231 cells at concentrations lower than 35 & mu;M, after 48 h of exposure. Thus, these complexes may be promising agents for the treatment of triple-negative MDA-MB-231 breast cancer.