College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, China.
Department of Agriculture and Biology Engineering, Taizhou Vocational College of Science & Technology, Taizhou, China.
J Sep Sci. 2018 Mar;41(6):1479-1488. doi: 10.1002/jssc.201701117. Epub 2018 Feb 6.
This work deals with the enantioseparation of α-amino acids by chiral ligand exchange high-speed countercurrent chromatography using N-n-dodecyl-l-hydroxyproline as a chiral ligand and copper(II) as a transition metal ion. A biphasic solvent system composed of n-hexane/n-butanol/aqueous phase with different volume ratios was selected for each α-amino acid. The enantioseparation conditions were optimized by enantioselective liquid-liquid extractions, in which the main influence factors, including type of chiral ligand, concentration of chiral ligand and transition metal ion, separation temperature, and pH of the aqueous phase, were investigated for racemic phenylalanine. Altogether, we tried to enantioseparate 15 racemic α-amino acids by the analytical countercurrent chromatography, of which only five of them could be successfully enantioseparated. Different elution sequence for phenylalanine enantiomer was observed compared with traditional liquid chromatography and the proposed interactions between chiral ligand, transition metal ion (Cu ), and enantiomer are discussed.
本工作采用 N-十二烷基-l-羟基脯氨酸作为手性配体，铜(II)作为过渡金属离子，通过手性配体交换高速逆流色谱法对手性氨基酸进行对映体拆分。为每种α-氨基酸选择了由正己烷/正丁醇/水组成的不同体积比的双相溶剂体系。通过对映选择性液-液萃取优化了对映体拆分条件，考察了手性配体的类型、手性配体和过渡金属离子的浓度、分离温度和水相 pH 等主要影响因素。总共尝试通过分析型逆流色谱拆分 15 种外消旋的α-氨基酸，其中只有 5 种能够成功拆分。与传统的液相色谱相比，观察到苯丙氨酸对映体的洗脱顺序不同，并讨论了手性配体、过渡金属离子(Cu)和对映体之间的相互作用。
