Product Name: L-(+)-Selenomethionine
Synonyms: (S)-(+)-2-AMINO-4-(METHYLSELENO)BUTANOIC ACID;(S)-2-AMINO-4-(METHYLSELENO)BUTYRIC ACID;SEMET;SELENOMETHIONINE, L-(+)-;SELENO-L-METHIONINE;L-(+)-2-AMINO-4-(METHYLSELENO)BUTANOIC ACID;L-(+)-SELENOMETHIONINE;L-SELENOMETHIONINE
Molecular Formula: C5H11NO2Se
Molecular Weight: 196.11
CAS Number: 3211-76-5
The L-isomer of selenomethionine, known as Se-met and Sem, is a common natural food source of selenium. In vivo, selenomethionine is randomly incorporated instead of methionine and is readily oxidized. Its antioxidant activity arises from its ability to deplete reactive species. Selenium and sulfur are chalcogen elements that share many chemical properties and the substitution of methionine to selenomethionine may have no effect on protein structure and function. However, the incorporation of selenomethionine into tissue proteins and keratin in horses causes alkali disease. Alkali disease is characterized by emaciation, loss of hair, deformation and shedding of hooves, loss of vitality and erosion of the joints of long bones.
Incorporation of selenomethionine into proteins in place of methionine aids the structure elucidation of proteins by X-ray crystallography using multi-wavelength anomalous diffraction (MAD). The incorporation of heavy atoms such as selenium helps solving the phase problem in X-ray crystallography.
It has been suggested that selenomethionine, which is an organic form of selenium, is easier for the human body to absorb than selenite, which is an inorganic form. It was determined in a clinical trial that selenomethionine is absorbed 19% better than selenite.