[Au2(phen2Me)2(?-O)2](PF6)2, a novel dinuclear gold(III) complex showing excellent antiproliferative properties

A novel dioxo-bridged dinuclear gold(III) complex with two 2,9-
dimethylphenanthroline ligands was synthesized and thoroughly characterized.
Its crystal structurewas solved, and its solution behavior assessed. Remarkably, this
compound revealed excellent antiproliferative properties in vitro against a wide
panel of 36 cancer cell lines, combining a high cytotoxic potency to pronounced
tumor selectivity. Very likely, these properties arise from an innovative mode of
action (possibly involving histone deacetylase inhibition), as suggested by COMPARE
analysis. In turn, electrospray ionization-mass spectrometry studies provided
valuable insight into its molecular mechanisms of activation and of interactionwith
protein targets. Gold(III) reduction, dioxo bridge disruption, coordinative gold(I)
binding to the protein, and concomitant release of the phenanthroline ligand were
proposed to occur upon interaction with superoxide dismutase, used here as a
model protein. Because of the reported results, this new gold(III) compound
qualifies itself as an optimal candidate for further pharmacological testing.