Anti-Bredt-Like Triterpenoids from Mycelial Cultures of the Edible Mushroom cf. .

Sixteen undescribed triterpene glycosides, oudecanarins A-P (-), were isolated from cultures of basidiomycete cf. TBRC-BCC 85371. Oudecanarins A-G (-) contain a bicyclo[4.3.1]decene system bearing the bridgehead double bond as a DE ring of pentacyclic triterpene. The unique carbon skeleton was confirmed by the X-ray crystallographic analysis of oudecanarin B (). The proposed plausible late-stage biosynthetic pathway for oudecanarin A () was supported by chemical conversion experiments.