title: Preparative isolation and purification of trans-3,5,4'-trihydroxystilbene-4'-O-beta-D-glucopyranoside and (+)catechin from Rheum tanguticum Maxim. ex Balf. using high-speed counter-current chromatography by stepwise elution and stepwise increasing the flow-rate of the mobile phase.
abstract: Preparative high-speed counter-current chromatography (HSCCC) was successfully used for isolation and purification of trans-3,5,4'-trihydroxystilbene-4'-O-beta-D-glucopyranoside (compound 1) and (+)catechin (compound 2) from Rheum tanguticum Maxim. ex Balf. by stepwise elution with a pair of two-phase solvent system composed of ethyl acetate-ethanol-water (25:1:25, v/v) and (5:1:5, v/v), and stepwise increasing the flow-rate of the mobile phase from 0.8 to 2.0 mlmin(-1) after 5 h. The preparative HSCCC separation was performed on 250 mg of crude extract yielding pure compound 1 (10.2 mg) and compound 2 (26.7 mg) all at purities of over 96% in a single run. The structures of the two compounds have been elucidated by means of spectroscopic methods including MS and 1H, 13C nuclear magnetic resonance spectroscopy.
authors.affiliation: School of Pharmaceutical Sciences, Peking University Health Science Center, Department of Natural Medicine, No. 38, Xueyuan Road, Beijing 100083, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Jin
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Tu
mesh_terms: D002392:Catechin / Q000302:isolation & purification*; D003377:Countercurrent Distribution / Q000379:methods*; D005960:Glucosides / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D012250:Rheum / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013267:Stilbenes / Q000302:isolation & purification*
chemical_list: D005960:Glucosides; D013267:Stilbenes; C505532:trans-3,5,4'-trihydroxystilbene-4'-O-beta-D-glucopyranoside; D002392:Catechin