Amyrin is a triterpenoid compound commonly found in plants. It is also known as taraxasterol, taraxerol, and ursolic acid. Amyrin has variously been referred to as alpha-amyrin, beta-amyrin, and delta-amyrin, based on the position of the double bond in the molecule. Other synonymic terms for the compound include 3beta-hydroxy-urs-12-en-28-oic acid and erythro-urs-12-en-28-oic acid. The chemical structure of amyrin is related to other triterpenes such as oleanolic acid, betulinic acid, and asiatic acid. These compounds are known for their medicinal properties and have been studied for their various therapeutic applications in traditional and modern medicine.