title: [New dibenzofuran and anthraquinone from 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 analyses of spectral data.
  
  
  RESULTS
  Two compounds were obtained and identified as 3, 6-diacetyl-2, 7, 9-trihydroxy-8, 9b-dimethyl-1 [9bH]-dibenzofuranone(1) and 1, 3, 8-trihydroxy4, 6-dimethyl-9, l0-anthracenedione(2), respectively.
  
  
  CONCLUSIONS
  Compounds 1 and 2 were new compounds and were named as longiusnine and longissimausnone, respectively.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Feng
authors.forename: Xiuwei
authors.initials: X
authors.lastname: Yang
mesh_terms: D000880:Anthraquinones / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification*; D001572:Benzofurans / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D020949:Usnea / Q000737:chemistry*
chemical_list: D000880:Anthraquinones; D001572:Benzofurans; C023614:dibenzofuran