Biological and medicinal aspects of vanadium

The importance of vanadium in life processes is addressed, emphasising the vanadium cofactors in vanadate-dependent haloperoxidases and vanadium-nitrogenases. Structural and functional model compounds for these enzymes are introduced, and the use of haloperoxidase models in the enantioselective oxygenation of thioethers is discussed. Specific attention is given to the redox interaction on the one hand, and stabilisation by coordination on the other hand, in the systems vanadium(III, IV and V) plus (bio-related) thiofunctional compounds, since these interactions should be of some importance in vanadium speciation under physiological conditions. With respect to the medicinal potential of vanadium compounds, their insulin-mimetic behaviour and hence efficacy in the oral treatment of both forms of diabetes mellitus is extemporated.