Selenium, Biologically Active Compounds
Selenium is a heavy analog of sulfur and its derivatives have similar chemical properties to those of sulfur. However, selenium compounds are more nucleophilic and are more stable in lower oxidation states. These differences lead to selenorganic compounds playing an important role in maintenance of redox balance in the physiological environment.
Selenium is a heavier analog of sulfur. Chemical properties of selenium and sulfur atoms (bond energies, ionization potentials, atom sizes) are nearly identical. Thus, most organoselenium compounds are the analogs of organosulfur ones.
However, there are a few substantial differences in chemical properties between sulfur and selenium. Due to the presence of an additional filled electron shell, selenium accommodates additional electrons better than sulfur. It has a stronger preference for lower oxidation states compared to sulfur (Se+6is much less...
- Bjornstedt M, Odlander B, Kuprin S, Claesson HE, Holmgren A (1996) Selenite incubated with NADPH and mammalian thioredoxin reductase yields selenide, which inhibits lipoxygenase and changes the electron spin resonance spectrum of the active site iron. Biochemistry 35:8511–8516CrossRefPubMedGoogle Scholar