What is "selenomethionine"

n. (context amino acid English) An amino acid related to methionine by the replacement of its sulfur atom by one of selenium

Selenomethionine is a naturally occurring amino acid. The L-selenomethionine enantiomer is the main form of selenium found in Brazil nuts, cereal grains, soybeans, and grassland legumes, while Se-methylselenocysteine, or its γ-glutamyl derivative, is the major form of selenium found in Astragalus, Allium, and Brassica species. In vivo, selenomethionine is randomly incorporated instead of methionine. Selenomethionine is readily oxidized.

Selenomethionine's antioxidant activity arises from its ability to deplete reactive oxygen species.