Three New Lanostane Triterpenoids from Inonotus obliquus

Abstract Three new lanostane‐type triterpenoids, inonotsulides A, B, and C ( 1 – 3 , resp.) were isolated from the sclerotia of Inonotus obliquus ( Pers .: Fr.) (Japanese name: Kabanoanatake ; Russian name: Chaga ). Their structures were determined to be (20 R ,24 S )‐3 β ,25‐dihydroxylanost‐8‐en‐20,24‐olide ( 1 ), (20 R ,24 R )‐3 β ,25‐dihydroxylanost‐8‐en‐20,24‐olide ( 2 ), and (20 R ,24 S )‐3 β ,25‐dihydroxylanosta‐7,9(11)‐dien‐20,24‐olide ( 3 ) on the basis of chemical transformation, NMR spectroscopy including 1D and 2D ( 1 H, 1 H‐COSY, NOESY, HMQC, HMBC), EI‐MS, and single‐crystal X‐ray analysis.