title: [Studies on chemical constituents from herbs of Usnea longissima].
abstract: OBJECTIVE
  To study the chemical constituents of Usnea longissima.
  
  
  METHODS
  The compounds were isolated and purified by the methods of solvent extraction and chromatographic technique, and their structures were identified on the basis of the analysis of spectral data or comparison with those of authentic sample.
  
  
  RESULTS
  Thirteen compounds were obtained and identified as ethyl hematommate (1), friedelin (2), beta-amyrin (3), beta-sitosterol (4), methyl-2,4-dihydroxy-3,6-dimethylbenzoate (5), barbatinic acid (6), zeorin (7), ethyl orsellinate (8), 3beta-hydroxy-glutin-5-ene (9), oleanolic acid (10), (+)-usnic acid (11), methylorsellinate (12), and 4-methyl-2,6-dihydroxy-benzaldehyde (13).
  
  
  CONCLUSIONS
  Compounds 2, 3, 5, and 8-10 were isolated from this genus for the first time, and compounds 1,4 were obtained from this plant for the first time.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing 100191, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Feng
authors.forename: Xiuwei
authors.initials: X
authors.lastname: Yang
authors.forename: Siduo
authors.initials: S
authors.lastname: Su
authors.forename: Chuan
authors.initials: C
authors.lastname: He
mesh_terms: D009930:Organic Chemicals / Q000032:analysis / Q000302:isolation & purification; D020949:Usnea / Q000737:chemistry*
chemical_list: D009930:Organic Chemicals