Taurine, or 2-aminoethanesulfonic acid, is an organic acid that is a major constituent of bile, and can be found in lower amounts in the tissues of many animals including humans. (metazoa). Taurine is also found in plants, fungi, and some bacterial species, but at lower levels. Taurine is a derivative of the sulfur-containing (sulfhydryl) amino acid, cysteine.
Taurine is named after the Latin taurus, which means bull, as it was first isolated from Ox bile in 1827 by Austrian scientists Friedrich Tiedemann and Leopold Gmelin. It is often called an amino acid, even in scientific literature, but it lacks a carboxyl group and therefore does not qualify as an amino acid in biochemical terminology. It does contain a sulfonate group and may be called an amino sulfonic acid. Small polypeptides have been identified which contain taurine but to date no aminoacyl tRNA synthetase has been identified as specifically recognizing taurine and capable of incorporating it onto a tRNA.