title: Preparative separation of gambogic acid and its C-2 epimer using recycling high-speed counter-current chromatography.
abstract: A recycling counter-current chromatographic system was first set up with a high-speed counter-current chromatography instrument coupled with a column switching valve. This system was first successfully applied to the preparative separation of epimers, gambogic acid and epigambogic acid from Garcinia hanburyi using n-hexane-methanol-water (5:4:1, v/v/v) as the two-phase solvent system. As a result, 28.2 mg gambogic acid and 18.4 mg epigambogic acid were separated from 50 mg of mixture. Their purities were both above 97% as determined by HPLC. The chemical structures were then identified by their (1)H NMR and (13)C NMR spectra.
authors.affiliation: Chinese Medicine Laboratory, Hong Kong Jockey Club Institute of Chinese Medicine, ShaTin N.T., Hong Kong.
authors.forename: Quan Bin
authors.initials: QB
authors.lastname: Han
authors.forename: Jing Zheng
authors.initials: JZ
authors.lastname: Song
authors.forename: Chun Feng
authors.initials: CF
authors.lastname: Qiao
authors.forename: Lina
authors.initials: L
authors.lastname: Wong
authors.forename: Hong Xi
authors.initials: HX
authors.lastname: Xu
mesh_terms: D003377:Countercurrent Distribution / Q000379:methods*; D013237:Stereoisomerism; D044004:Xanthones / Q000302:isolation & purification*
chemical_list: D044004:Xanthones; C052659:gambogic acid