Phosphole-Gold(I) and Phosphole-Platinum(II) Therapeutic Agents as Irreversible Inhibitors of Human Disulfide Reductases

The homodimeric flavoenzymes thioredoxin reductase (TrxR) and glutathione reductase (GR) are linked to many cellular processes such as antioxidant defense, redox balance, regulation of various proteins, and nucleotide metabolism. Hence, their active Cys-thiols site as well as the redox-active Sec (selenocysteine) of TrxR are interesting drug targets. We have shown that AuI-complexes 1a,b and PtII-complexes 2a,b bearing phosphole ligands are highly potent inhibitors of these enzymes and thus promising lead compounds for the development of novel anti-tumor, anti-proliferative and anti-parasitic drugs. An X-ray diffraction study of modified hGR has shown that (phosphine)AuCl complexes act as prodrugs with a stepwise ligand displacement.


Molecules image Enzyme image Enzyme image

Refined structure of hGR modified by 1a. Active site: Cys58-S-Au-S-Cys63 as central unit, K+-ion (electrostatic interaction with Cys58), PO43--group (interaction with K+, glycerol and His467 of the symmetry-related monomer).

The gold and platinum complexes are prepared in Rennes, and their biological properties are studied by :

Prof. Dr. M. D. Katja Becker, Justus-Liebig-University, Giessen (Germany)

Dr. Elisabeth Davioud-Charvet, Dr. Christel Herold-Mende, University of Heidelberg (Germany)

Dr. Karin Fritz-Wolf, Max Planck Institute for Medical Research, Heidelberg (Germany)

Dr. Katalin Tóth, German Cancer Research Center, Heidelberg (Germany)


References