L-异亮氨酸聚合物手性配体交换固定相的制备及对DL-氨基酸的拆分

手性配体交换色谱固定相;单分散树脂;L-异亮氨酸;DL-氨基酸;对映体分离     

单分散树脂键合手性配体交换色谱固定相拆分DL-氨基酸

以单分散交联聚甲基丙烯酸环氧丙酯-甲基丙烯酸乙二醇双酯(PGMA/EDMA)树脂为基质合成了L-脯氨酸键合手性配体交换固定相,并用于DL-氨基酸的直接光学拆分,考察了流动相pH值、金属离子浓度、流速及温度等因素对DL-氨基酸对映体拆分的影响。结果表明,该固定相在配体交换色谱模式下可对多对DL-氨基酸进行良好的拆分。     

α-羟基酸在不同的手性配体交换色谱固定相上分离性能的考察

合成了L-羟基脯氨酸，L-脯氨酸，L-苯丙氨酸3种硅胶链合手性配体交换色谱固定相，并用于α-羟基酸的直接光学分离，取得了较为满意的结果。对不同的手性配体交换色谱固定相的分离性能进行了比较，并详细考察了流动相pH值、金属离子浓度、柱温等因素对分离效果的影响，从而进一步优化了色谱分离条件。     

用丙烯酸类手性配位体交换树脂拆分DL-氨基酸的研究

本文利用以铜络合的手性L-脯氨酸聚丙烯酸类交换树脂为柱色谱的固定相,对DL-苯丙氨酸、DL-苯丝氯酸、DL-酪氨酸、DL-色氨酸、DL-组氨酸等芳香氨基酸的拆分进行了研究。实验结果表明,除了组氨酸之外,其它氨基酸均能完全拆开,且D型先于L型流出柱子。通过测定L-Pro-PGMA-Cu(Ⅱ)的红外光谱,提出了它在配位体交换过程中的配位结构模型。     

Resolution of the Optical Isomers of Underivatisized Amino Acids on Chemically Bonded Chiral Phases by Ligand Exchange Chromatography

Abstract

A method for the direct separation of racemates by HPLC is described. A chiral stationary phase is synthesized, suitable for ligand exchange chromatography. L-proline is chemically bonded to silica gel via 3-glycidoxypropyltrimethoxysilane. The bonded support is loaded with Cu(II) ions as a complexing agent. Complete resolution of amino acid racemates can be obtained in less than ten minutes. α-values up to 3.5 are observed.     

Enantioselective Recognition of Aspartic Acids by Chiral Ligand Exchange Potentiometry

Enantioselective resolution is realized by combining potentiometry with ligand exchange (CE) in a new method called chiral ligand exchange potentiometry (CLEP). A chiral selector, N‐carbobenzoxy‐L ‐aspartic acid (N‐CBZ‐L‐Asp), preferentially recognizes D ‐aspartic acid (D‐Asp) and undergoes ligand exchange with the enantiomeric labile coordination complexes of [Cu(II)(D‐Asp)₂] or [Cu(II)(L‐Asp)₂] to form a diastereoisomeric complex [(D‐Asp)Cu(II)(N‐CBZ‐L‐Asp)] (a) or [(L‐Asp)Cu(II)(N‐CBZ‐L‐Asp)] (b). Considerable stereoselectivity occurs in the formation of these diastereoisomeric complexes, and their net charges were ?2 (a) and 0 (b), respectively, resulting in different Nernst factor (electrode slope), thus enabling chiral D‐Asp to be distinguished by potentiometry without any pre‐ or postseparation processes.     

对映体选择性配体交换膜的制备和DL-氨基酸的拆分

制备了一种新型光学分离膜,即带有Ｌ－脯氨酸手性选择子的交联聚乙烯醇膜,考察了ＤＬ－酪氨酸,ＤＬ－苯丙氨酸和ＤＬ－色氨酸通过膜的对映体选择性渗透性能。发现Ｌ－氨基酸优先透过膜,消旋氨基酸透过膜的对映体拆分机理类似于手性配体交换色谱方法拆分消旋氨基酸的机理,在ＤＬ－氨基酸的对映体选择性膜透过中,对映体选择性吸附着重要的作用。     

新型L-羟脯氨酸聚合物键合手性固定相的制备及对手性化合物的拆分

以单分散亲水性交联聚甲基丙烯酸环氧丙酯-甲基丙烯酸乙二醇双酯(PGMA/EDMA)树脂为载体,制备新型L-羟脯氨酸聚合物键合高效手性配体交换固定相。该固定相在配体交换分离模式下,以0.2mol/LNaAc和0.1mmol/LCu(Ac)2水溶液(pH5.2)为流动相,柱温为30℃～50℃,对衍生和非衍生的D,L-氨基酸和α-羟基酸等9种手性化合物进行了高效液相色谱拆分。详细考察了流动相pH值、温度、流速和进样量对手性分离的影响,选择了合适的色谱分离条件。结果表明,所拆分的9种手性化合物,有5种手性化合物能得到基线分离,最好的分离因子α=2.32。     

α-氨基酸在L-脯氨酸手性配体交换色谱固定相上的分离

合成了L-脯氨酸硅胶键合手性配体交换色谱固定相，并用于α-氨基酸的直接光学分离，详细考察了流动相pH值、金属离子浓度、流速、柱温以及进样量等因素对分离效果的影响，从而进一步优化了色谱分离条件。     

手性配体交换色谱的研究进展

手性配体交换色谱技术将配体交换原理与色谱技术相结合,拓宽了液相色谱、电泳以及逆流色谱的应用层面,为部分难分离手性物质提供了有效的分离与检测方法。该文参考了近年来国内外的相关文献,综述了手性配体交换技术在液相色谱、电泳与逆流色谱等领域中的应用进展;总结了手性配体交换色谱技术的基本原理、影响因素、优缺点等,并对手性配体交换色谱技术的趋势进行了展望。     

Chiral Recognition and Resolution Based on Helical Polymers

Helical polymers have attracted a great deal of attention and been extensively investigated due to their various applications.One of the most important applications of helical polymers is chiral recognition and resolution of enantiomers for the reason that a pair of enantiomers is commonly with different physiological and toxicological behaviors in biological systems.Helical polymers usually present unexpected high chiral recognition ability to a variety of racemic compounds.What's more,the chiral recognition and resolution abilities of the system are dependent on the highly ordered helical structures of the helical polymers.This mini review mainly focuses on the recent progress in chiral recognition and resolution based on helical polymers.The synthetic methodology for helical polymers is firstly discussed briefly.Then recent advances of chiral recognition and resolution systems based on helical polymers,especially polyacetylenes and polyisocyanides,are described.We hope this mini review will inspire more interest in developing helical polymers and encourage further advances in chiral-related disciplines.     

主链光学活性聚合物与手性催化剂

自从 50年代早期发现 Ziegler- Natta催化剂以来 [1] ,立体有规聚合研究迅速发展 .80年代初 ,Kaminsky等 [2 ] 以手性配体锆化合物为催化剂 ,得到了高度等规的聚丙烯及聚 1 -丁烯 ,为 Ziegler-Natta催化剂均相化开拓了全新局面 .其后 Ziegler-Natta催化剂的一些链引发、链模板增长及终止机理 ,在均相条件下得以充分的研究 [3～ 5] .最近几年 ,又出现了用手性催化剂使无光学活性的单体聚合而成主链光学活性聚合物的研究 [6～ 8] ,并迅速成为金属有机化学家和高分子化学家关注的热点 .合成手性聚合物的研究 ,主要集中在模仿天然聚合物 ,阐…     

硅胶键合手性配体交换固定相键合量对α-氨基酸拆分的影响

 合成了两种不同键合量的L 脯氨酸硅胶键合手性配体交换固定相 ,装柱后利用配体交换法分离了一系列的α 氨基酸。实验结果表明键合量不同的固定相对α 氨基酸的拆分能力差别较大。     

Direct Resolution of Enantiomers of DL-Amino Acids by Thin-Layer Chromatography with Vancomycin as Impregnating Agent

JPC – Journal of Planar Chromatography – Modern TLC -     

Polydopamine-Assisted Rapid One-Step Immobilization of L-Arginine in Capillary as Immobilized Chiral Ligands for Enantioseparation of Dansyl Amino Acids by Chiral Ligand Exchange Capillary Electrochromatography

Herein, a novel L-arginine (L-Arg)-modified polydopamine (PDA)-coated capillary (PDA/L-Arg@capillary) was firstly fabricated via the basic amino-acid-induced PDA co-deposition strategy and employed to constitute a new chiral ligand exchange capillary electrochromatography (CLE-CEC) method for the high-performance enantioseparation of D,L-amino acids (D,L-AAs) with L-Arg as the immobilized chiral ligand coordinating with the central metal ion Zn(II) as running buffer. Assisted by hydrothermal treatment, the robust immobilization of L-Arg on the capillary inner wall could be facilely achieved within 1 h, prominently improving the synthesis efficiency and simplifying the preparation procedure. The successful preparation of PDA/L-Arg coatings in the capillary was systematically characterized and confirmed using several methods. In comparison with bare and PDA-functionalized capillaries, the enantioseparation capability of the presented CLE-CEC system was significantly enhanced. Eight D,L-AAs were completely separated and three pairs were partially separated under the optimal conditions. The prepared PDA/L-Arg@capillary showed good repeatability and stability. The potential mechanism of the greatly enhanced enantioseparation performance obtained by PDA/L-Arg@capillary was also explored. Moreover, the proposed method was further utilized for studying the enzyme kinetics of L-glutamic dehydrogenase, exhibiting its promising prospects in enzyme assays and other related applications.     

基于手性配体交换反应立体选择性萃取分离氧氟沙星对映体

基于配体交换反应,研究了氧氟沙星对映体在含有Cu²⁺和N-n-十二烷基-L-脯氨酸手性配体(L)两相体系中的分配平衡.在不同pH条件下,考察了Cu²⁺在含有N-n-十二烷基-L-脯氨酸两相中的分布;研究了pH,Cu²⁺浓度,手性配体浓度等因素对氧氟沙星对映体在两相中的分配系数(K)和分离因子(α)的影响.实验结果表明,N-n-十二烷基-L-脯氨酸对R-氧氟沙星对映体萃取能力大于对S-对映体的萃取能力;pH对K和α的影响很大,在pH值小于3.5时,L₂Cu二元配合物的生成在热力学上看是不适宜的,萃取时pH宜大于3.5;手性配体和Cu²⁺摩尔比为2:1,K和α最佳;使用2×1中空纤维膜对氧氟沙星对映体进行萃取分离,出口水相氧氟沙星对映体浓度比值(S/R)约为1.72.     

L-苯丙氨酸键合手性配体交换色谱固定相的制备及手性拆分

合成了L-苯丙氨酸键合手性配体交换固定相，用元素分析和红外光谱对固定相进行了表征；该固定相在反相条件下对DL-氨基酸对映体有良好的拆分能力。