Synthesis and anti-cancer activities of a water soluble gold(III) porphyrin

Gold(III) compounds continue to be explored for their potential utility as anticancer agents. A recognized limitation is the reactivity of gold(III), which is typically reduced to the more labile gold(I) state under physiological conditions. The use of porphyrins can overcome this problem. However, to date the stabilization provided by the use a strongly chelating porphyrin is offset by the poor solubility of the resulting complex in aqueous media. In this work, we describe the synthesis and in vitro anti-cancer activity of a gold(III) porphyrin complex with relatively good aqueous solubility. As judged from standard antiproliferation assays, this complex displays an IC50 of 9 mu M for the A2780 human ovarian cancer cell line. This is a higher level of potency than displayed by two related control systems.