Gold Compounds as Anticancer Agents: A Systematic Study of Gold–Protein Metalation

The main goal of the present work has been to elucidate the modes of action of cytotoxic gold compounds which are still poorly understood.Accordingly, a small panel of representative cytotoxic gold compounds have been extensively characterised from the chemical point of view. Particular attention has been paid to the description of their solution behaviour and of their stability under experimental conditions similar to those of the biological tests. Afterward, a systemic investigation has been carried out to describe the reactivity of gold compounds with likely protein targets; in particular, their reactions with a few model proteins have been assayed through ESI MS experiments. Remarkably, the peculiar coordination properties of the gold(III) center allow the obtainment of metal complexes showing an almost co-planar localization of extended aromatic surfaces, that seem highly suitable for a particular nucleic acid targeting: DNA G-quadruplex.