title: Separation of flavonoids from the seeds of Vernonia anthelmintica Willd by high-speed counter-current chromatography.
abstract: Several flavonoids including 2',3,4,4'-tetrahydroxychalcone, 5,6,7,4'-tetrahydroxyflavone and butin, were separated from the seeds of Vernonia anthelmintica Willd by high-speed counter-current chromatography using a two-step operation. Two different types of solvent systems were used: chloroform-dichloromethane-methanol-water (2:2:3:2, v/v) and 1,2 dichloroethane-methanol-acetonitrile-water (4:1.1:0.25:2, v/v). From 1 kg of seeds of Vernonia anthelmintica Willd the method yielded about 45 mg of 2',3,4,4'-tetrahydroxychalcone, 40mg of 5,6,7,4'-tetrahydroxyflavone, and 55 mg of butin. Each isolated component showed 95-97% purity as determined by high-performance liquid chromatography analysis. These purified compounds were characterized by MS and NMR.
authors.affiliation: Beijing Institute of New Technology Application, Beijing 100035, China.
authors.forename: Guilian
authors.initials: G
authors.lastname: Tian
authors.forename: Ubin
authors.initials: U
authors.lastname: Zhang
authors.forename: Tianyou
authors.initials: T
authors.lastname: Zhang
authors.forename: Fuquan
authors.initials: F
authors.lastname: Yang
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Ito
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D012639:Seeds / Q000737:chemistry; D035741:Vernonia / Q000737:chemistry*
chemical_list: D005419:Flavonoids; D007202:Indicators and Reagents