title: Preparative isolation and purification of theaflavins and catechins by high-speed countercurrent chromatography.
abstract: High-speed countercurrent chromatography (HSCCC) has been applied for the separation of theaflavins and catechins. The HSCCC run was carried out with a two-phase solvent system composed of hexane-ethyl acetate-methanol-water-acetic acid (1:5:1:5:0.25, v/v) by eluting the lower aqueous phase at 2 ml/min at 700 rpm. The results indicated that pure theaflavin, theaflavins-3-gallate, theaflavins-3'-gallate and theaflavin-3,3'-digallate could be obtained from crude theaflavins sample and black tea. The structures of the isolated compounds were positively confirmed by (1)H NMR and (13)C NMR, MS analysis, HPLC data and TLC data. Meanwhile, catechins including epigallocatechin gallate, gallocatechin gallate, epicatechin gallate and epigallocatechin were isolated from the aqueous extract of green tea by using the same solvent system. This study developed a modified method combined with enrichment theaflavins method by using HSCCC for separation of four individual theaflavins, especially for better separation of theaflavins monogallates.
authors.affiliation: Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Furong District, Changsha, Hunan 410128, People's Republic of China.
authors.forename: Kunbo
authors.initials: K
authors.lastname: Wang
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Liu
authors.forename: Jian-an
authors.initials: JA
authors.lastname: Huang
authors.forename: Xinrong
authors.initials: X
authors.lastname: Dong
authors.forename: Lubing
authors.initials: L
authors.lastname: Song
authors.forename: Yu
authors.initials: Y
authors.lastname: Pan
authors.forename: Fang
authors.initials: F
authors.lastname: liu
mesh_terms: D002392:Catechin / Q000302:isolation & purification*; D003377:Countercurrent Distribution / Q000379:methods*; D005415:Flavins / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D013662:Tea / Q000737:chemistry
chemical_list: D005415:Flavins; D013662:Tea; D002392:Catechin