title: New lanostane-type triterpene acids from wolfiporia extensa.
abstract: BACKGROUND
  Dried sclerotia of Wolfiporia extensa (Polyporaceae) is used to invigorate the spleen and to tranquilize the mind in Chinese herbal medicine. Lanostane-type triterpene acids were regard as major secondary metabolites from dried sclerotia of W. extensa.
  
  
  RESULTS
  Three new lanostane-type triterpene acids, 3-epi-benzoyloxyl-dehydrotumulosic acid (1), 3-epi-(3'-O-methyl malonyloxy)-dehydrotumulosic acid (2) and 3-epi-(3'-hydroxy-3'-methylglutaryloxyl)-dehydrotumulosic acid (3), were isolated from the sclerotia of W. extensa, together with 3 known lanostane derivatives (4-6). Their structures were elucidated on the basis of spectroscopic analysis, including 1D and 2D-NMR techniques.
  
  
  CONCLUSIONS
  Six lanostane derivatives including three new triterpene acids and three known compounds were reported from the sclerotia of W. extensa in this paper.
authors.affiliation: School of Chinese Pharmacy, Beijing University of Chinese Medicine, No, 6, Zhonghuan South Road, Wangjing District, Beijing, 100102, People's Republic of China. shirb@126.com.
authors.forename: Gaimei
authors.initials: G
authors.lastname: She
authors.forename: Nailiang
authors.initials: N
authors.lastname: Zhu
authors.forename: Shuai
authors.initials: S
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Yinying
authors.initials: Y
authors.lastname: Ba
authors.forename: Changqing
authors.initials: C
authors.lastname: Sun
authors.forename: Renbing
authors.initials: R
authors.lastname: Shi