Pentacyclic triterpenoids, fuscotorunones A and B, with ε-caprolactone in ring E from Fuscoporia torulosa

Abstract Fuscoporia torulosa (Pers.) (Hymenochaetaceae) is a mushroom forming woody fruiting body on living or dead trees. Two curious pentacyclic triterpenoids, fuscotorunones A and B, each of which has a unique e-caprolactone in ring E, were isolated from the fruiting bodies of F. torulosa. The structures of fuscotorunones A and B were elucidated using MS analyses, IR spectrum and extensive 2D-homo and heteronuclear NMR data interpretation. Furthermore, a predicted biosynthetic pathway from 2,3-oxidosqualene to fuscotorunones A and B in F. torulosa is proposed.