Synthesis, structural characterization and cytotoxicity of bimetallic chlorogold(I) phosphine complexes employing functionalized phosphinoferrocene carboxamides

Gold( I) phosphine complexes of the general formula [AuCl(Ph(2)PfcCONHY-kappa P)], where Y is CH2CO2Me (7), CH2CONH2 (8), CH2CH2OH (9), CH(CH2OH)(2) (10), C(CH2OH)(3) (11), and CH2SO3(HNEt3) (12), and fc is ferrocene-1,1'-diyl, were prepared from [AuCl(tht)] (tht = tetrahydrothiophene) and the appropriate phosphinoferrocene carboxamides (1-6). The compounds were characterized by spectroscopic and analytical methods, and the molecular structures of 7 and 9 were determined by single-crystal X-ray crystallography. Complexes 7-12 exerted antiproliferative activity against the human ovarian cancer cells in vitro. The IC50 values ranged ca. 0.3-3.7 mu M for the A2780 cell line, and 3.1-20 mu M for the cisplatin resistant cell line A2780R, with complex 7 being the most cytotoxic against both cell types. IC50 values for the non-tumorigenic human embryonic kidney (HEK) cells, serving as a measure of a general toxicity, were found in roughly similar ranges, i.e. 0.9-6.8 mu M. (c) 2013 Elsevier B.V. All rights reserved.