title: [Study on the structure of epimerides of cycloclausenamide].
abstract: OBJECTIVE
  To study the structures of the epimerides of cycloclausenamide.
  
  
  METHODS
  The structures of compound I, extracted from Clausena lansium (Lour.) Skeels, and synthesized compound III were determined by single crystal X-ray diffraction analysis. The stereo-structures of compound II and IV were also built up through Tripos force field based on crystal structures of compound I and III.
  
  
  RESULTS
  The molecular formula and molecular weight were found to be C18H17O2N and 279.34 respectively. Compound I crystallized in monoclinic system, space group P2(1) with a = 0.5928(1), b = 1.5014(1), c = 1.6190(1) nm, V = 1.4410(3) nm3, Z = 4, Dx = 1.288 g.cm-3, Rf = 0.075, Rw = 0.073(w = 1/sigma 2|F|), S = 3.983; compound III crystallized in triclinic system, space group P1 with a = 0.5667(1), b = 1.2934(1), c = 2.1119 (1) nm, alpha = 102.17(1), beta = 90.25(1), gamma = 102.65(2) degrees, V = 1.4770(5) nm3, Z = 4, Dx = 1.224 g.cm-3, Rf = 0.047, Rw = 0.051(w = 1/sigma 2|F|), S = 0.467.
  
  
  CONCLUSIONS
  These results showed that compound I and III both are cycloclausenamide except that the directions of the phenyl group on C6 are different. Cycloclausenamide can form 4 pairs of epimerides but the directions of the phenyl group does not affect their energy in free state.
authors.affiliation: Institute of Material Medica, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100050, China.
authors.forename: B
authors.initials: B
authors.lastname: Zhao
authors.forename: J G
authors.initials: JG
authors.lastname: Zhou
authors.forename: G
authors.initials: G
authors.lastname: Meng
authors.forename: Z M
authors.initials: ZM
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Lu
authors.forename: T H
authors.initials: TH
authors.lastname: Zhou
mesh_terms: D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification; D008968:Molecular Conformation; D010946:Plants, Medicinal / Q000737:chemistry; D027821:Rutaceae / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; C481911:cycloclausenamide