Mu Xiaoyu, Qi Li, Qiao Juan, Yang Xinzheng, Ma Huimin
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.
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.
Anal Chim Acta. 2014 Oct 10;846:68-74. doi: 10.1016/j.aca.2014.07.022. Epub 2014 Jul 19.
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.
建立了一种以Zn(II)为中心离子、L-4-羟基脯氨酸为手性配体与γ-环糊精（γ-CD）配位的手性配体交换毛细管电泳（CLE-CE）方法，用于氨基酸（AAs）和二肽的对映体分离。系统研究了各种分离参数的影响，包括运行缓冲液的pH值、Zn(II)与L-4-羟基脯氨酸的比例、配合物和环糊精（CDs）的浓度。优化后发现，在pH 8.2的100.0mM硼酸、5.0mM醋酸铵、3.0mM Zn(II)、6.0mM L-羟基脯氨酸和4.0mM γ-CD的运行电解质条件下，八对标记的AAs和六对标记的二肽可以实现基线分离。对AAs和二肽进行了定量分析，获得了良好的线性关系（r(2)≥0.997）和良好的重复性（RSD≤3.6%）。此外，该方法还应用于测定AAs和二肽的对映体纯度。同时，对手性金属配合物和γ-CD协同作用的可能对映体识别机制进行了探索和简要讨论。
