The amyrins are three closely related natural chemical compounds of the triterpene class. They are designated α-amyrin (ursane skeleton),[3]β-amyrin (oleanane skeleton),[4] and δ-amyrin. Each is a pentacyclic triterpenol with the chemical formula C30H50O. They are widely distributed in nature and have been isolated from a variety of plant sources such as epicuticular wax. In plant biosynthesis, α-amyrin is the precursor of ursolic acid and β-amyrin is the precursor of oleanolic acid.[5] All three amyrins occur in the surface wax of tomato fruit.[6][7] α-Amyrin is found in dandelion coffee.[citation needed]
^Bauer, Stefan; Schulte, Erhard; Thier, Hans-Peter (2004). "Composition of the surface wax from tomatoes II. Quantification of the components at the ripe red stage and during ripening". European Food Research and Technology. 219: 487–491. doi:10.1007/s00217-004-0944-z. S2CID90472894.
^Simão da Silva, Kathryn A.B.; Paszcuk, Ana F.; Passos, Giselle F.; Silva, Eduardo S.; Bento, Allisson Freire; Meotti, Flavia C.; Calixto, João B. (August 2011). "Activation of cannabinoid receptors by the pentacyclic triterpene α,β-amyrin inhibits inflammatory and neuropathic persistent pain in mice". Pain. 152 (8): 1872–1887. doi:10.1016/j.pain.2011.04.005. ISSN0304-3959. PMID21620566. S2CID23484784.