Peroxidase Activity of Organic Selenides: Mechanistic Insights from Quantum Chemistry

Organoselenium compounds can reduce H2O2 and organic hydroperoxides mimicking the antioxidant activity of glutathione peroxidase (GPx). This catalytic process reduces the peroxides, which play a key role in oxidative stress, thus inhibiting their harmful action. Thus, it is not surprising that a lot of effort has been devoted toward the synthesis and design of numerous GPx mimics, which, nevertheless, show minor efficiency when compared to the native enzyme. In this context, quantum chemistry tools are an important support to rational drug design, because they allow to investigate in detail the structural and electronic properties of the organochalcogen compound with the aim of establishing links with its potential catalytic activity. In this review, we have collected the information from the available quantum chemistry studies about the reactivity of organic selenides with peroxides and thiols, delineating the analysis on monoselenides and ebselen, which will be critically discussed and gathered for a more complete overview of their GPx-like activity; few novel results will be presented to interpret very recent experimental mechanistic findings.