title: SEPARATION OF THE MINOR FLAVONOLS FROM FLOS GOSSYPII BY HIGH-SPEED COUNTERCURRENT CHROMATOGRAPHY.
abstract: An effective high-speed countercurrent chromatography (HSCCC) method was established for further separation and purification of four minor flavonols in addition to five major flavonols which were reported by our previous study from extracts of Flos Gossypii. HSCCC was performed with three two-phase solvent systems composed of n-hexane-ethyl acetate-methanol-water (7.5:15:6:7, v/v), (2.5:15:2:7, v/v) and (0:1:0:1, v/v). The separation was repeated 3 times, and 3.8 mg of 8-methoxyl-kaempferol-7-O-β-D-rhamnoside (HPLC purity 98.27%), 6.7 mg of astragalin (HPLC purity 94.18%), 3.3 mg of 4'-methoxyl-quercetin-7-O-β-D-glucoside (HPLC purity 94.30%) and 8.2 mg of hyperoside (HPLC purity 93.48%) were separated from 150 mg of the crude sample. The chemical structures of the flavonols were confirmed by MS, (1)H NMR and (13)C NMR. Meanwhile, the results indicated that the target compound with smaller K value (<0.5) can be separated by increasing column length of HSCCC. And four separation rules of flavonols according to the present study and references were summarized, which can be used as a useful guide for separation of flavonols by HSCCC.
authors.affiliation: Xinjiang Key Laboratory of Plant Resources and Natural Products Chemistry, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Zhao
authors.forename: Dongyu
authors.initials: D
authors.lastname: Gu
authors.forename: Amatjan
authors.initials: A
authors.lastname: Ayupbek
authors.forename: Yun
authors.initials: Y
authors.lastname: Huang
authors.forename: Jun
authors.initials: J
authors.lastname: Dou
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Ito
authors.forename: Tianyou
authors.initials: T
authors.lastname: Zhang
authors.forename: Haji Akber
authors.initials: HA
authors.lastname: Aisa