Ebselen is an excellent scavenger of peroxynitrite and is used for the treatment of cerebral infarctions. Ebselen oxide, formed by the oxidation of ebselen, lacks antioxidant activity, indicating that it can serve as a negative control for ebselen.[1]
Reference:
[1]. Lass, A., Witting, P., Stocker, R., et al. Inhibition of copper- and peroxyl radical-induced LDL lipid oxidation by ebselen: Antioxidant actions in addition to hydroperoxide-reducing activity. Biochimica et Biophysica Acta 1303, 111-118 (1996).