Madecassic acid is a pentacyclic triterpenoid that is ursane substituted by a carboxy group at position 28 and hydroxy groups at positions 2, 3, 6 and 23 (the 2alpha,3beta,6beta stereoisomer). It has a role as an antioxidant and a plant metabolite. It is a pentacyclic triterpenoid, a tetrol and a monocarboxylic acid. It derives from a hydride of an ursane.