3-Methyl-2-oxovaleric acid is an abnormal metabolite that arises from the incomplete breakdown of branched-chain amino acids. 3-Methyl-2-oxovaleric acid is a neurotoxin an acidogen and a metabotoxin. A neurotoxin causes damage to nerve cells and nerve tissues.

Glucagon-like peptide 2 (GLP-2) is a recently identified intestinal epithelium-specific growth factor that has been shown to reduce the severity of inflammatory disorders of the intestine in rodent models. Currently Glucagon-Like Peptide 2 is used as a potential therapeutic agent for the human subjects with a broad variety of intestinal diseases characterized by intestinal damage and insufficiency.

D-glutamic acid, the enantiomer of L-glutamic acid, is widely used in medicine and food.