title: Separation of catalpol from Rehmannia glutinosa Libosch. by high-speed countercurrent chromatography.
abstract: The bioactive iridoid component catalpol was successfully separated by high-speed countercurrent chromatography with high purity from the partially purified crude extract of Rehmannia glutinosa. A polar two-phase solvent system composed of ethyl acetate-n-butanol-water (2:1:3, v/v/v) was selected by thin-layer chromatography and run on a preparative scale where the lower aqueous phase was used as the mobile phase with a head-to-tail elution mode. A 105 mg quantity of the partially purified sample containing 39.2% catalpol was loaded on a 270-mL capacity high-speed countercurrent separation column, yielding 35 mg of catalpol at 95.6% purity. The chemical structure of catalpol was determined by comparison with the high-performance liquid chromatography retention time of standard substance as well as the (1)H NMR spectrum.
authors.affiliation: College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, China Laboratory of Bioseparation Technology, Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA sqtong@zjut.edu.cn.
authors.forename: Shengqiang
authors.initials: S
authors.lastname: Tong
authors.affiliation: College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, China Zhejiang Institutes of Traditional Chinese Medicine and Natural Drug, Hangzhou, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.affiliation: College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.affiliation: College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, China.
authors.forename: Jizhong
authors.initials: J
authors.lastname: Yan
authors.affiliation: Laboratory of Bioseparation Technology, Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Ito
mesh_terms: D003377:Countercurrent Distribution / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification*; D057888:Iridoid Glucosides / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D032267:Rehmannia / Q000737:chemistry*
chemical_list: D004365:Drugs, Chinese Herbal; D057888:Iridoid Glucosides; C078040:catalpol