title: Chiral separation of brompheniramine enantiomers by recycling high-speed countercurrent chromatography using carboxymethyl-β-cyclodextrin as a chiral selector.
abstract: A recycling high-speed countercurrent chromatography protocol was proposed for the enantioseparation of brompheniramine by employing β-cyclodextrin derivatives as a chiral selector. The two-phase solvent system of n-hexane/isobutyl acetate/0.10 mol/L phosphate buffer solution with a volume ratio of 2:4:6 was selected by a series of extraction experiments. Factors that affected the distribution of the enantiomers over the two-phase system (e.g., the type and concentration of β-cyclodextrin derivatives = pH value of the aqueous solution, and the separation temperature) were also investigated. In addition, the theory of thermodynamics is applied to verify the feasibility of the enantioseparation process and the corresponding results demonstrate that this separation process is feasible. The optimized conditions include carboxymethyl-β-cyclodextrin concentration of 0.010 mol/L, pH of 7.5, and temperature of 5°C. Under the optimal conditions, the purities of both monomer molecules were over 99%, and the recovery yields were 88% for (+)-brompheniramine and 85% for (-)-brompheniramine, respectively.
authors.affiliation: Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, P.R. China.
authors.forename: Panliang
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, P.R. China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Xie
authors.affiliation: Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, P.R. China.
authors.forename: Kewen
authors.initials: K
authors.lastname: Tang
authors.affiliation: Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, P.R. China.
authors.forename: Weifeng
authors.initials: W
authors.lastname: Xu
mesh_terms: D001977:Brompheniramine / Q000737:chemistry / Q000302:isolation & purification*; D003377:Countercurrent Distribution; D015394:Molecular Structure; D013237:Stereoisomerism; D013816:Thermodynamics; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D047392:beta-Cyclodextrins; C441457:carboxymethyl-beta-cyclodextrin; D001977:Brompheniramine
keywords: Brompheniramine; Chiral separation; Cyclodextrins; High-speed countercurrent chromatography