A pentacyclic triterpenoid that is lupane having a double bond at position 20(29) as well as 3beta-hydroxy and 28-hydroxymethyl substituents. ChEBI: Betulin is a pentacyclic triterpenoid that is lupane having a double bond at position 20(29) as well as 3beta-hydroxy and 28-hydroxymethyl substituents. It has a role as a metabolite, an antiviral agent, an analgesic, an anti-inflammatory agent and an antineoplastic agent. It is a pentacyclic triterpenoid and a diol. It derives from a hydride of a lupane.