Background: The growing interest on the redox modulation in living systems broadly involved
selenium derivatives that during the last twenty years were often claimed powerful antioxidants but that were
also clearly correlated to several important biological effects sometimes, unfortunately, associated to a certain
toxicity. Comparing the antioxidant activity of different organoselenium structures it can be observed that
sometimes quite different reaction mechanisms are involved.
Method: We propose here a classification based on the nature of the selenenylated functional group. Beside the
natural glutathione peroxidase-like activity, other biological interactions were proposed and we report now an
overview of the state of art pointing the attention also to the testes used to evaluate and demonstrate the biological
Conclusion: New prospective on the use of selenium and tellurium derivatives as Redox modulators, were discussed
throughout a series of selected examples. The possibility to obtain from organoselenium derivatives
molecules endowed with hormetic effect or able to act as selective inhibitor of specific enzyme will be discussed.