The comparative evaluation of the physical and chemical properties of gold compounds.

A wide range of modern physical and chemical techniques can be used to evaluate the properties of gold compounds. These allow the identification of the design features which control their pharmacological activity: the oxidation state (formal charge) on the gold atom, number and types of atoms bonded to gold (coordinated ligands), the stereochemical arrangement of ligands around gold (coordination geometry), and specific targeting groups in the ligands. The polymeric, hydrophilic, gold thiolate compounds are contrasted with the monomeric, lipophilic triethylphosphine gold compound auranofin (AF). The dynamic ligand exchange reactions of the 2 classes of drugs differ markedly; however other reactions are possible, and may lead to some common intermediates in vivo. This conclusion is based on preliminary results using nuclear magnetic resonance spectroscopy, a technique which allows us to monitor reactions in intact cells.