New Heteroleptic RuII/Diphosphine Complexes with Cytotoxicity against Human Breast and Murine Ascitic Sarcoma 180 Tumor Cells

Abstract

The preparation, characterization, theoretical calculations and biological application of four RuII complexes with 2-picolinate (pic), 2,2’-bipyridine (bipy) and P-P as ligands [P-P = 1,1-bis(diphenylphosphino)methane (dppm-1), 1,2-bis(diphenylphosphino)ethane (dppe-2), 1,3-bis(diphenylphosphino)propane (dppp-3) or 1,1’-bis(diphenylphosphino)ferrocene (dppf-4)], is here presented. The complexes 1-4, with general formula [Ru(pic)(P-P)(bipy)]PF6, were characterized by elemental analysis and by infrared (IR), UV-Vis, nuclear magnetic resonance (NMR 1H and 13P{1H}) spectroscopies, cyclic voltammetry and X-ray crystallography technique. Additionally, preliminary in vitro tests against human breast (MDA-MB-231) and murine ascitic sarcoma 180 (S180) tumor cell lines were carried out, and compared with cisplatin, a reference drug. The drug concentration at which 50% of the cells are viable relative to the control (IC50) values found for complexes 1, 2, 3 and 4 against MDA-MB-231 tumor cells were around 14.6, 7.6, 3.3 and 0.4 μM, respectively, while against S180 tumor cells these complexes showed IC50 values of 71.9, 31.3, 11.2 and 3.5 μM, respectively. Therefore, the complexes were more active against MDA-MB-231 than S180.