CHAPTER 10.2: Current Research on Mimics and Models of Selenium‐Containing Antioxidants Check Access

In this chapter, several selenium‐based compounds that functionally mimic the activity of the selenoenzyme glutathione peroxidase (GPx) are discussed. These compounds include (1) cyclic selenenyl amides with a selenium‐nitrogen bond, (2) diaryl diselenides, and (3) aliphatic as well as aromatic monoselenides. On the basis of recent experimental and theoretical investigations, the reason for the poor GPx activity of ebselen in the presence of aryl or benzylic thiol cofactors such as PhSH or BnSH is described. The discrepancies in the GPx‐like activities of other classes of compounds can be ascribed mainly to the difference in the reactivity of thiol cofactors. The catalytic activity of synthetic selenium compounds is influenced to a large extend by the nature of the thiol substrate. The existence of strong Se···O/N noncovalent interactions in the selenenyl sulfide intermediates of the catalytic cycle generally decreases the antioxidant activity as such interactions facilitate an attack of thiol at selenium rather than at sulfur. In addition to the GPx activity, it is explained that several organoselenium compounds can act as efficient scavengers of peroxynitrite, a potent biological oxidant and nitrating species.