title: Supercritical fluid extraction of catechins from Cratoxylum prunifolium dyer and subsequent purification by high-speed counter-current chromatography.
abstract: Supercritical fluid extraction of tea catechins including epigallocatechin-3-O-gallate (EGCG) and epicatechin-3-O-gallate (ECG) from Cratoxylum prunifolium Dyer was performed. The optimization of parameters was carried out using an analytical-scale supercritical fluid extraction (SFE) system designed in our laboratory. Then the extraction was scaled up by 100 times using a preparative SFE system under a set of optimized conditions of 40 degrees C, 25 MPa and modified CO2 with 80% ethanol aqueous solution. The combined yield of EGCG and ECG reached about 1 mg per 1 g of tea leaves where the solubility was near 1.4 x 10(-4) mass fraction of CO2 fluid. EGCG and ECG of high purity (>98%) were obtained from the crude preparative extract by high-speed counter-current chromatography.
authors.affiliation: Beijing Institute of New Technology Application, China.
authors.forename: X L
authors.initials: XL
authors.lastname: Cao
authors.forename: Y
authors.initials: Y
authors.lastname: Tian
authors.forename: T Y
authors.initials: TY
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
mesh_terms: D002392:Catechin / Q000302:isolation & purification*; D002845:Chromatography / Q000379:methods*; D018515:Plant Leaves / Q000737:chemistry; D013662:Tea / Q000737:chemistry*
chemical_list: D013662:Tea; D002392:Catechin