title: Preparative separation of isoquinoline alkaloids from Stephania yunnanensis by pH-zone-refining counter-current chromatography.
abstract: In this paper, five isoquinoline alkaloids were successfully separated from a crude extract of Stephania yunnanensis using pH-zone-refining counter-current chromatography in single-step. With a two-phase solvent system composed of methyl-tert-butyl ether (MtBE)-acetonitrile-water (2:2:3, v/v) where triethylamine (10 mM) was added to the upper organic phase as a retainer and hydrochloric acid (5 mM) to the aqueous mobile phase as an eluter. From 1.4 g crude extract, 68.7 mg isocorydine, 78.2 mg corydine, 583.4 mg tetrahydropalmatine, 36.3 mg N-methylasimilobine, and 47.3 mg anonaine were separated with purities over 90%. Their structures were identified by (1)H NMR, (13)C NMR, ESI-MS data.
authors.affiliation: Department of Chemistry, Zhejiang University, 38 Zheda Road, Hangzhou 310027, China.
authors.forename: Ruilin
authors.initials: R
authors.lastname: Hu
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Dai
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Lu
authors.forename: Yuanjiang
authors.initials: Y
authors.lastname: Pan
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification*; D003377:Countercurrent Distribution / Q000379:methods*; D005021:Ethylamines / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007546:Isoquinolines / Q000737:chemistry / Q000302:isolation & purification*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010936:Plant Extracts / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D031607:Stephania / Q000737:chemistry*
chemical_list: D000097:Acetonitriles; D000470:Alkaloids; D005021:Ethylamines; D007546:Isoquinolines; D010936:Plant Extracts; C016162:triethylamine; C032159:acetonitrile