title: Large-scale separation of alkaloids from Gelsemium elegans by pH-zone-refining counter-current chromatography with a new solvent system screening method.
abstract: A rapid and simple solvent system screening method was developed for pH-zone-refining counter-current chromatography (CCC) separation, which was much easier to find a suitable solvent system than the traditional method. Using this method, an optimal solvent system composed of hexane-ethyl acetate-methanol-water (3:7:1:9, v/v) was selected for pH-zone-refining CCC separation of alkaloids from the stems of Gelsemium elegans, where 10mM triethylamine (TEA) was added to the upper organic stationary phase as a retainer and 10mM hydrochloric acid (HCl) to the aqueous mobile phase as an eluter. As a result, six oxindole alkaloids, 420mg 19-xo-gelsenicine, 456mg gelsemine, 723mg koumine, 379mg 11-methoxygelsemamide, 342mg gelsenicine and 318mg humantenine were successfully purified in one step from 4.5g crude extract with the purity of over 95%, respectively. The structures of the oxindole alkaloids were identified by ESI-MS, (1)H NMR and (13)C NMR.
authors.affiliation: Shandong Analysis and Test Center, Shandong Academy of Sciences, 19 Keyuan Street, Jinan, Shandong 250014, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Fang
authors.forename: Jie
authors.initials: J
authors.lastname: Zhou
authors.forename: YunLiang
authors.initials: Y
authors.lastname: Lin
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
authors.forename: Qinglei
authors.initials: Q
authors.lastname: Sun
authors.forename: Jia-Lian
authors.initials: JL
authors.lastname: Li
authors.forename: Luqi
authors.initials: L
authors.lastname: Huang
mesh_terms: D000470:Alkaloids / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution / Q000379:methods*; D031450:Gelsemium / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D019906:Nuclear Magnetic Resonance, Biomolecular; D010936:Plant Extracts / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry
chemical_list: D000470:Alkaloids; D010936:Plant Extracts; D012997:Solvents
keywords: Alkaloids; Gelsemium elegans; Separation and purification; pH-zone-refining counter-current chromatography