Structure and cytotoxic properties of some selected gold(III) complexes

Gold(III) complexes, isostructural and isoelectronic with platinum(II) comp lexes, are of potential interest as antitumor drugs. We prepared four repre sentative square planar gold(III) complexes - [AuCl3(Hpm)], [AuCl2(esal)], [AuCl(dien)]Cl-2 and [Au(en)(2)]Cl-3 - and characterized them both in the s olid state and in solution. Thereafter, the cytotoxicity of these compounds was evaluated in vitro against the A2780 human ovarian tumor cell line tha t was used as the reference cell line. Remarkably, all these gold(III) comp lexes showed significant cytotoxic effects, [AuCl2(esal)] showing a potency comparable to cisplatin. The present gold(III) complexes were also tested on the corresponding cisplatin-resistant line and revealed they were able t o overcome resistance to cisplatin to a large extent. The implications of t hese findings for the development of new gold(III) complexes to be tested a s antitumor agents are discussed.