title: Enantioseparation of chiral aromatic acids by multiple dual mode counter-current chromatography using hydroxypropyl-β-cyclodextrin as chiral selector.
abstract: This work concentrates on extending the utilization of multiple dual mode (MDM) counter-current chromatography in chiral separations. Two aromatic acids, 2-(6-methoxy-2-naphthyl)propionic acid (NAP) and 2-phenylpropionic acid (2-PPA), were enantioseparated by MDM counter-current chromatography using hydroxypropyl-β-cyclodextrin (HP-β-CD) as chiral selector. The two-phase solvent systems consisting of n-hexane/ethyl acetate 0.1 mol/L phosphate buffer pH 2.67 containing 0.1 mol/L HP-β-CD (7.5:2.5:10 for NAP and 7:3:10 for 2-PPA, v/v/v) were used. Conventional MDM and modified MDM were compared according to peak resolution under current separation mechanism. The influence of elution time after the first-phase inversion and number of cycles for MDM were investigated. Peak resolution of NAP and 2-PPA increased from 0.62 to 1.05 and 0.72 to 0.84, respectively, using optimized MDM conditions. Being an alternative elution method for counter-current chromatography, MDM elution greatly improved peak resolution in chiral separations.
authors.affiliation: College of Pharmaceutical Science, Zhengjiang University of Technology, Hangzhou, China. sqtong@zjut.edu.cn
authors.forename: Shengqiang
authors.initials: S
authors.lastname: Tong
authors.forename: Ye
authors.initials: Y
authors.lastname: Zheng
authors.forename: Jizhong
authors.initials: J
authors.lastname: Yan
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D000146:Acids, Carbocyclic / Q000737:chemistry* / Q000302:isolation & purification*; D003377:Countercurrent Distribution / Q000295:instrumentation / Q000379:methods*; D013237:Stereoisomerism; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D000146:Acids, Carbocyclic; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin