title: Separating four diastereomeric pairs of dihydroflavonol glycosides from Engelhardia roxburghiana using high performance counter-current chromatography.
abstract: Four pairs of diastereomers were successfully isolated and separated from the water extract of Engelhardia roxburghiana by high performance counter-current chromatography (HPCCC) using a two-step procedure. The diastereomers were initially separated by a two-phase solvent system composed of n-hexane-n-butanol-0.1% trifluoroacetic acid (1:2:3, v/v/v) and followed by the same solvent system using hydroxypropyl-β-cyclodextrin (HP-β-CD) as an additive. The chromatographic conditions, elution mode, and concentrations of the additive were refined. The two-step HPCCC isolation yielded 43.7mg (2S, 3S)-astilbin, 27.6mg (2R, 3R)-astilbin, 5.9mg (2S, 3R)-astilbin, 4.8mg (2R, 3S)-astilbin, 6.9mg (2S, 3S)-engelitin, 3.1mg (2R, 3R)-engelitin, 8.2mg (2S, 3R)-engelitin, and 6.0mg (2R, 3S)-engelitin from 384mg crude extract in four runs with purities of 99.3%, 96.2%, 99.8%, 99.9%, 97.0%, 96.5%, 96.1%, and 96.8%, respectively. The present study revealed that HP-β-CD can be used as an additive in HPCCC to effectively improve the resolution of the diastereomers. The established HPCCC method may serve as an approach to obtain high purity diastereomers on a large scale.
authors.affiliation: Institute of Food and Nutraceutical Science, School of Agriculture & Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Haiming
authors.initials: H
authors.lastname: Shi
authors.affiliation: Institute of Food and Nutraceutical Science, School of Agriculture & Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Man
authors.initials: M
authors.lastname: Liu
authors.affiliation: Institute of Food and Nutraceutical Science, School of Agriculture & Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.affiliation: Institute of Food and Nutraceutical Science, School of Agriculture & Biology, Shanghai Jiao Tong University, Shanghai 200240, China; Department of Nutrition and Food Science, University of Maryland, 0112 Skinner Building, College Park, Maryland 20742, USA.
authors.forename: Boyan
authors.initials: B
authors.lastname: Gao
authors.affiliation: Institute of Food and Nutraceutical Science, School of Agriculture & Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Zhongfei
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Institute of Food and Nutraceutical Science, School of Agriculture & Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: yugeniu@sjtu.edu.cn.
authors.forename: Yuge
authors.initials: Y
authors.lastname: Niu
authors.affiliation: Institute of Food and Nutraceutical Science, School of Agriculture & Biology, Shanghai Jiao Tong University, Shanghai 200240, China; Department of Nutrition and Food Science, University of Maryland, 0112 Skinner Building, College Park, Maryland 20742, USA. Electronic address: lyu5@umd.edu.
authors.forename: Liangli Lucy
authors.initials: LL
authors.lastname: Yu
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D003377:Countercurrent Distribution; D044948:Flavonols / Q000032:analysis / Q000302:isolation & purification; D006027:Glycosides / Q000032:analysis* / Q000302:isolation & purification; D029525:Juglandaceae / Q000737:chemistry* / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry*; D013237:Stereoisomerism; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D044948:Flavonols; D006027:Glycosides; D010936:Plant Extracts; D047392:beta-Cyclodextrins; C522936:engeletin; D000073738:2-Hydroxypropyl-beta-cyclodextrin; C099069:astilbin
keywords: Diastereomers; Dihydroflavonol glycosides; Engelhardia roxburghiana; High-performance counter-current chromatography; Hydroxypropyl-β-cyclodextrin