Taurine
Also known as 2-aminoethanesulfonic acid. A non-protein, sulfur-containing amino acid with a variety of important physiological functions. Taurine is used in the formation of bile salts (which facilitate fat digestion/absorption); and is needed for osmoregulation, proper cardiac function and neurological development. Taurine is also abundant in skeletal muscle and has antioxidant activity.
See the Taurine review for more information.