Erythrodiol is a pentacyclic triterpenoid that is beta-amyrin in which one of the hydrogens of the methyl group at position 28 has been replaced by a hydroxy group. It is a plant metabolite found in olive oil as well as in Rhododendron ferrugineum and other Rhododendron species. It has a role as a plant metabolite. It is a pentacyclic triterpenoid, a primary alcohol, a secondary alcohol and a diol. It derives from a beta-amyrin.