title: Preparative isolation and purification of three flavonoid glycosides from Taraxacum mongolicum by high-speed counter-current chromatography.
abstract: A preparative high-speed counter-current chromatography (HSCCC) was successively applied to purify three flavonoid glycosides from the aerial part of Taraxacum mongolicum, a traditional Chinese medicine. Subsequent UV, MS, and NMR analyses have led to the characterization of three flavonoid glycosides including two new compounds isoetin-7-O-beta-D-glucopyranosyl-2'-O-alpha-L-arabinopyranoside and isoetin-7-O-beta-D-glucopyranosyl-2'-O-alpha-D-glucopyranoside, and a known compound, isoetin-7-O-beta-D-glucopyranosyl-2'-O-alpha-D-xyloypyranoside, which were first isolated from T. mongolicum. The two-phase solvent system composed of ethyl acetate/n-butanol/water (2:1:3, v/v/v) was performed in HSCCC. Consequently, a total of 25.7 mg isoetin-7-O-beta-D-glucopyranosyl-2'-O-alpha-L-arabinopyranoside, 19.1 mg isoetin-7-O-beta-D-glucopyranosyl-2'-O-alpha-D-glucopyranoside, and 10.6 mg isoetin-7-O-beta-D-glucopyranosyl-2'-O-alpha-D-xyloypyranoside were obtained with purity of 98.7, 98.3, and 99.1%, respectively, as determined by HPLC from 500 mg enriched extract after cleaning-up by polyamide resin.
authors.affiliation: School of Chemistry and Chemical Engineering, Central South University, Changsha, China. shuyshi@gmail.com
authors.forename: Shuyun
authors.initials: S
authors.lastname: Shi
authors.forename: Yuping
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhao
authors.forename: Kelong
authors.initials: K
authors.lastname: Huang
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution; D004365:Drugs, Chinese Herbal / Q000737:chemistry; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification*; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D013056:Spectrophotometry, Ultraviolet; D031205:Taraxacum / Q000737:chemistry*
chemical_list: D004365:Drugs, Chinese Herbal; D005419:Flavonoids; D006027:Glycosides