Anticancer activity and X-ray structure determination of gold(I) complexes of 2-(diphenylphosphanyl)-1-aminocyclohexane

Phosphane gold(I) complexes, [Au(ACP)Cl] (1) and [Au(ACP)(S₂CNR₂)] (2–4) where ACP = 2-(diphenylphosphanyl)-1-aminocyclohexane or (2-aminocyclohexyl)diphenylphosphane, and R = methyl, ethyl, benzyl, were synthesized and characterized by elemental analysis, FTIR and multinuclear NMR spectroscopy. The molecular structure of one of the compounds, [Au(ACP)Cl] (1), was determined by single crystal X-ray diffraction analysis, which revealed a linear geometry around the Au(I) center. The crystal structure is stabilized by N–H⋯Cl hydrogen bonding interactions. The in vitro cytotoxicity of the complexes was evaluated against three cancer cells, A549 (human lung cancer), HeLa (human cervical cancer) and HepG2 (human liver cancer) cell lines. Three of the four complexes showed excellent in vitro cytotoxicity; their inhibition effect is much greater than that of cisplatin.