Oxidized glutathione represents one percent of the total cellular glutathione (GSH) concentration. Glutathione, the most abundant intracellular non-protein thiol, is formed in cells as a means of protecting against hydroperoxides. As is well known, peroxides are unstable and, upon decomposition, form very deadly free radicals. Glutathione scavenges these free radicals using the thiol bridge (-SH groups), which generates water and yields the oxidized form of glutathione.
The appropriate name for glutathione is N(N-y-L-glutamyl-L-cysteinyl-glycine). The easiest way of describing this compound is to envision two identical molecules connected to each other by a thiol bridge. The identical molecules consist of glutamic acid connected through the gamma carbon carboxylic acid terminal to the amino group of the amino acid cysteine, which is connected to the amino group of the amino acid glycine. These molecules are then joined at the alpha carbon of each cysteine moieties through a methylene carbon and a thiol bridge.
Oxidized glutathione is commercially available and manufactured as a natural antioxidant dietary supplement.