Synthesis, characterization and anti proliferative effect of [Au(en)2]Cl3 and [Au(N-propyl-en)2]Cl3 on human cancer cell lines

Two Au(III) complexes of the type [Au(en)(2)]Cl-3 (2a) and [Au(N-pr-en)(2)]Cl-3 (3a) were synthesized by reacting Auric acid (HAuCl4 center dot 3H(2)O) with 2 equiv. ethylenediamine (en) or N-alkyl substituted ethylene-diamine ligands. This metallodrug was characterized by various analytical and spectroscopic techniques such as elemental analysis, UV-Vis. Far-IR, H-1 NMR and solution C-13 as well as solid C-13 and N-15 NMR. Potentiality of [Au(en)(2)]Cl-3 and [Au(N-pr-en)(2)]Cl-3 as an anti-cancer agent were investigated by measuring some relevant physicochemical and biochemical properties such as stability of Au-N bonds by vibrational stretching from Far IR as well as cytotoxicity and stomach cancer cell inhibiting effect, respectively. The solid-state N-15 NMR chemical shift shows that the ligand is strongly bound to gold(III) centre via N atoms. The computational study of 2a shows that the gold coordination sphere adopts distorted square planar geometry with bidentate ethylenediamine ligands acting as a tetradentate chelate. While stable in the solution state, the in vitro biological studies performed with these compounds 2a in solution showed higher activity towards the inhibitory effects of the human cancer cell lines such as prostate cancer (PC-3) and gastric carcinoma (SGC-7901) than that of the N-substituted gold(III) complex (3a). Cytotoxicity of the new compounds has also been estimated in PC-3 and SGC-7901 cells. (C) 2011 Elsevier B.V. All rights reserved.