title: [Study on the solubility changes of Rhizoma Coptidis' main chemical constituents influenced by the proportion of Rhizoma Coptidis and Fructus Evodiae].
abstract: OBJECTIVE
  To investigate the relationship between the solubility of Rhizoma Coptidis' main chemical constituents and the proportion of Rhizoma Coptidis and Fructus Evodiae.
  
  
  METHODS
  9 samples were selected in which the proportion of Rhizoma Coptidis and Fructus Evodiae were 1:0, 6:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:6 and 0:1, respectively. The samples' water-extracts were analyzed by RP-HPLC. Then solubility changes of eight chemical constituents were calculated, and the regression equations were established.
  
  
  RESULTS
  Among the eight chemical constituents, one was independent on the change of proportion of Rhizoma Coptidis and Fructus Evodiae, six having linear relationship. A new constituent was detected, and there was nonlinear relationship between its quantity and the proportion of the couple.
  
  
  CONCLUSIONS
  The solubility of Rhizoma Coptidis' main chemical constituents declines almost in the same scale when Rhizoma Coptidis and Fructus Evodiae are used as a couple, and a new constituent has been detected which can't be found in the mono-extraction.
authors.affiliation: Department of Chinese Medine Science and Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China.
authors.forename: Ming-xing
authors.initials: MX
authors.lastname: Peng
authors.forename: Yong-jiang
authors.initials: YJ
authors.lastname: Wu
authors.forename: Yi-yu
authors.initials: YY
authors.lastname: Cheng
mesh_terms: D001599:Berberine / Q000031:analogs & derivatives* / Q000032:analysis; D001600:Berberine Alkaloids / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D039323:Coptis / Q000737:chemistry*; D004338:Drug Combinations; D004365:Drugs, Chinese Herbal / Q000032:analysis*; D032086:Evodia / Q000737:chemistry*; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D012995:Solubility
chemical_list: D001600:Berberine Alkaloids; D004338:Drug Combinations; D004365:Drugs, Chinese Herbal; C055785:jatrorrhizine; C034384:coptisine; D001599:Berberine; C005413:palmatine