title: Application and recovery of ionic liquids in the preparative separation of four flavonoids from Rhodiola rosea by on-line three-dimensional liquid chromatography.
abstract: A novel on-line three-dimensional liquid chromatography method was developed to separate four main flavonoids from Rhodiola rosea. Ethyl acetate/0.5 mol/L ionic liquid 1-butyl-3-methylimidazolium chloride aqueous solution was selected as the solvent system. In the first-dimension separation, the target flavonoids were entrapped and subsequently desorbed into the second-dimension high-speed countercurrent chromatographic column for separation. In the third-dimension chromatography, the residual ionic liquid in the four separated flavonoids was removed and the used ionic liquid was recovered. As a result, 35.1 mg of compound 1, 20.4 mg of compound 2, 8.5 mg of compound 3, and 10.6 mg of compound 4 were obtained from 1.53 g R. rosea extract. They were identified as rhodiosin, rhodionin, herbacetin, and kaempferol, respectively. The recovery of ionic liquid reached 99.1% of the initial amount. The results showed that this method is a powerful technology for the separation of R. rosea flavonoids and that the ionic-liquid-based solvent system has advantages over traditional solvent systems in renewable and environmentally friendly properties.
authors.affiliation: State key laboratory of food science and technology, School of Food Science and Technology, Jiangnan University, Wuxi, China.
authors.forename: Shufeng
authors.initials: S
authors.lastname: Ma
authors.forename: Liming
authors.initials: L
authors.lastname: Hu
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Ma
authors.forename: Wenping
authors.initials: W
authors.lastname: Lv
authors.forename: Hongxin
authors.initials: H
authors.lastname: Wang
mesh_terms: D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification*; D052578:Ionic Liquids / Q000737:chemistry*; D029771:Rhodiola / Q000737:chemistry*
chemical_list: D004365:Drugs, Chinese Herbal; D005419:Flavonoids; D052578:Ionic Liquids
keywords: Herbacetin; Ionic liquids; Multidimensional chromatography; Rhodiola rosea; Rhodionin; Rhodiosin