title: Separation of four flavonoids from Rhodiola rosea by on-line combination of sample preparation and counter-current chromatography.
abstract: Purification of four flavonoids from Rhodiola rosea was developed by on-line combination of sample preparation and counter-current chromatography (CCC). Flavonoid sample was prepared by dynamic ultrasonic-assisted and solid-phase extraction using ion liquids as extractant. The preparation conditions were optimized by D-optimal design as follows: 2mol/L of 1-ethyl-3-methylimidazolium bromide concentration, 360W of ultrasonic power, 1.5mL/min of flow rate, 35min of extraction time and 0.5mL (absorbent) per g (material) of absorbent amount. The prepared sample solution (20mL) was loaded and injected directly into CCC column for final separation. As a result, four flavonoids, herbacetin-3-O-β-d-glucopyranosyl-7-O-α-l-rhamnopyranoside 1 (40.1mg), kaempferol-3-O-β-d-glucopyranosyl-7-O-α-l-rhamn-opyranoside 2 (4.6mg), kaempferol 3-O-β-d-glucopyranoside-(2→1)-β-d-xylopyranoside 3 (20.2mg) and herbacetin-8-O-β-d-glucopyranoside 4 (22.5mg), were obtained from 20g of R. rosea material using ethyl acetate-n-butanol-H2O as solvent system at a ratio of 4:1:5 by CCC. Their structures were identified by ESI-MS/MS, NMR methods. Their purities determined by UPLC were 98.5%, 95.4%, 98.1% and 97.5%, respectively. Kaempferol-3-O-β-d-glucopyranosyl-7-O-α-l-rhamnopyranoside 2 and herbacetin-8-O-β-d-glucopyrano-side 4 were isolated for first time from R. rosea. The purification method was simple, efficient and evaded tedious sample preparation process.
authors.affiliation: State Key Laboratory of Food Science and Technology (Jiangnan University), School of Food Science and Technology, 1800 Lihu Road, 214122 Wuxi, China.
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Ma
authors.forename: Liming
authors.initials: L
authors.lastname: Hu
authors.forename: Qianyun
authors.initials: Q
authors.lastname: Fu
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Gu
authors.forename: Guanjun
authors.initials: G
authors.lastname: Tao
authors.forename: Hongxin
authors.initials: H
authors.lastname: Wang
mesh_terms: D001331:Automation; D003377:Countercurrent Distribution / Q000379:methods*; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification*; D029771:Rhodiola / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*
chemical_list: D005419:Flavonoids; D010936:Plant Extracts
keywords: Dynamic ultrasonic-assisted and solid-phase extraction; Flavonoids; HSCCC; Ionic liquids; Rhodiola rosea