title: Enantioseparation of dansyl amino acids and dipeptides by chiral ligand exchange capillary electrophoresis based on Zn(II)-L-hydroxyproline complexes coordinating with γ-cyclodextrins.
abstract: A chiral ligand exchange capillary electrophoresis (CLE-CE) method using Zn(II) as the central ion and L-4-hydroxyproline as the chiral ligand coordinating with γ-cyclodextrin (γ-CD) was developed for the enantioseparation of amino acids (AAs) and dipeptides. The effects of various separation parameters, including the pH of the running buffer, the ratio of Zn(II) to L-4-hydroxyproline, the concentration of complexes and cyclodextrins (CDs) were systematically investigated. After optimization, it has been found that eight pairs of labeled AAs and six pairs of labeled dipeptides could be baseline-separated with a running electrolyte of 100.0mM boric acid, 5.0mM ammonium acetate, 3.0mM Zn(II), 6.0mM L-hydroxyproline and 4.0mM γ-CD at pH 8.2. The quantitation of AAs and dipeptides was conducted and good linearity (r(2)≥0.997) and favorable repeatability (RSD≤3.6%) were obtained. Furthermore, the proposed method was applied in determining the enantiomeric purity of AAs and dipeptides. Meanwhile, the possible enantiorecognition mechanism based on the synergistic effect of chiral metal complexes and γ-CD was explored and discussed briefly.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Mu
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China. Electronic address: qili@iccas.ac.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Qi
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.
authors.forename: Juan
authors.initials: J
authors.lastname: Qiao
authors.affiliation: Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China. Electronic address: xyang@iccas.ac.cn.
authors.forename: Xinzheng
authors.initials: X
authors.lastname: Yang
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Ma
mesh_terms: D000596:Amino Acids / Q000302:isolation & purification*; D056831:Coordination Complexes / Q000737:chemistry; D003619:Dansyl Compounds / Q000302:isolation & purification*; D004151:Dipeptides / Q000302:isolation & purification*; D019075:Electrophoresis, Capillary / Q000379:methods; D006909:Hydroxyproline / Q000737:chemistry*; D015203:Reproducibility of Results; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry*; D047408:gamma-Cyclodextrins / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D056831:Coordination Complexes; D003619:Dansyl Compounds; D004151:Dipeptides; D047408:gamma-Cyclodextrins; D015032:Zinc; C023792:gamma-cyclodextrin; D006909:Hydroxyproline
keywords: Amino acid; Chiral ligand exchange capillary electrophoresis; Dipeptide; l-Hydroxyproline; γ-Cyclodextrin