Anti-cancer potential of gold complexes.

A full range of gold compounds is currently being investigated for their potential as anti-tumor agents. Gold(I) compounds related to the anti-arthritic drug continue to attract attention, especially those carrying biologically active molecules with anti-tumor activity in their own right. Tetrahedrally coordinated gold(I) compounds, that possibly target mitochondria, are under development with a particular focus upon moderating their hydrophilicity. A resurgence of interest in square-planar gold(III) compounds has occurred in the last decade. A wide variety of species: mono- and di-nuclear, neutral and charged, coordination and organometallic, etc. are being developed. Supporting many investigations are studies of mechanistic aspects of gold compounds but a clear understanding of the mechanism of action of these compounds has yet to be delineated.

Colloidal metallic gold is not bio-inert.

Metallic gold (Au degrees ) is a likely biotransformation product of monovalent gold, Au(I) whenever it is dissociated from in vivo ligands, Au degrees being formed either by bioreduction or by spontaneous dismutation (with co-production of trivalent gold). This review discusses the preparation and some biologically relevant properties of colloidal metallic gold (CMG) in its nano-particulate form. Tyndall's purple, a well characterised preparation of CMG, shows potent anti-arthritic activity in rats, approximately 10(3) times that of sodium aurothiomalate (Myocrysin). Even more remarkable is its broader spectrum of action in rats compared to this classic DMARD.