A novel chiral ligand exchange capillary electrophoresis for diols and polyols using borate anion as a central ion of the chiral selector

在手性配体交换毛细管电泳法中，氨基酸及其衍生物与铜(II)的络合物作为手性选择剂被广泛应用于氨基酸及其衍生物和α-羟基酸的手性拆分。另一方面，硼酸根与顺式-1，2-和顺式-1，3-二醇相互作用形成单环和螺环络合物，它们在水溶液中共存。最近，我们发现天然的DL-泛酸(DL-PTA)以硼酸盐为中心离子，(S)-3-氨基-1，2-丙二醇(SAP)为手性选择剂，用化学发光法进行了拆分。在这项研究中，我们研究了(1)在二元醇-硼酸盐体系中，DL-PTA的对映体分离机理和(2)在其他二元醇和多元醇对映体分离中的应用。(3)为了将所提出的共价修饰…应用于实际样品，我们还研究了共价修饰DNA(1)用~(13)&gt；C和~(11)&lt；11&gt；B核磁共振谱证实了二元和三元配合物在三元体系中平衡共存。变温热力学实验表明，三元配合物[B(SAP)(D-PTA)]^-比[B(SAP)(L-PTA)]^-更稳定。三元络合物可能有两个几何异构体，分子轨道计算表明：(5)D^-和L-对苯二甲酸三元络合物更有可能是几何异构体。在优化的(S)-[B(SAP)(D-PTA)]^-水溶液中，SAP和D-PTA配体相反取向形成较线性的结构，而非对映异构体(5)-[B(SAP)(L-PTA)]^-则具有折叠结构。由于三元络合物溶剂化结构的这种差异可以在毛细管电泳法中提供不同的电泳速度，因此DL-PTA在CE中的对映体分离合理地归因于含有各自三元络合物的平衡三元体系观察到的电泳迁移率的不同。(2)我们发现三种具有1，2-二醇结构的化合物(1-苯基-1，2-乙二醇，3-苯氧基-1，2-丙二醇和3-苯氧基-1，2-丙二醇)在(1S，2S，3R，用8-氨基萘甲烯-1，3，6-三磺酸衍生的六种还原单糖(甘露糖、半乳糖、岩藻糖、葡萄糖、木糖和阿拉伯糖)，以硼酸盐为中心离子，SAP为手性选择剂，同时在未处理的熔融石英毛细管内壁引入磺化基团。较少的磺酸钠

In chiral ligand exchange capillary electrophoresis(CLECE), copper(II) complexes with amino acids or their derivatives have been widely used as chiral selectors for the enantioseparation of amino acids, their derivatives, and α-hydroxy acids, where the ternary copper(II) complexes are formed by the ligand-exchange reaction of the chiral selector with the racemate. On the other hand, borate anion interacts with cis-1, 2- and cis-1, 3-diols to form monocyclic complex, and spirocyclic complex, which coexist in aqueous solution. Recently, we have found that native DL-pantothenic acid(DL-PTA) was enantioseparated by CLECE using borate as a central ion and(S)-3-amino-1, 2-propanediol(SAP) as a chiral selector. In this study, we studied (1) the mechanism of enantioseparation of DL-PTA in CLECE using a diol-borate system and (2) the application of CLECE for the enantioseparation of other diols and polyols. (3) In order to apply the proposed CLECE to real samples, we also studied covalent modif … More ication procedures to obtain capillary that gives reproducibile migration times for CE.(1) Using ^<13>C and^<11>B NMR, it was confirmed that the binary complexes and the ternary complexes coexist at equilibrium in the ternary system. Thermodynamic experiments by variable temperature ^<11>B NMR revealed that the ternary complex, [B(SAP)(D-PTA)]^-, was entropically more stable than [B(SAP)(L-PTA)]^-. Two geometrical isomers are possible for the respective ternary complexes, senuempmcal molecular orbital calculations indicated that(5) isomer is more probable for the respective ternary complexes with D^- and L-PTA. In the optimized structure of(S)-[B(SAP)(D-PTA)]^- in water, the SAP and D-PTA ligands were oppositely oriented to form a rather linear structure, while the diastereomer, (5)-[B(SAP)(L-PTA)]^-, have a folded structure. Because such a difference in the solvated structure of the ternary complexes can give different electrophoretic velocity in capillary electrophoresis, the enantioseparation of DL-PTA in CE is reasonably attributed to a difference in the observed electrophoretic mobility for the equilibrated ternary systems containing the respective ternary complexes.(2) We found that three compounds having 1, 2-diol structure(1-phenyl-1, 2-ethanediol, 3-phenoxy-1, 2-propanediol and 3-benzyloxy-1, 2-propanediol) were enantioseparated by ligand exchange micellar electrokinetic chromatography using(1S, 2S, 3R, 5S)-pinanediol as a chiral selector and borate anion as a central ion together with sodium dodecyl sulfate and that six reducing monosaccharides(mannose, galactose, fucose, glucose, xylose, and arabinose), which were derivatized with 8-aminonaphtalene-1, 3, 6-trisufonate, were simultaneously enantioseparated by CLECE using borate as a central ion and SAP as a chiral selector.(3) Sulfonated groups were chemically introduced to an inner wall of untreated fused silica capillary with 2-(4-chlorosulfonylphenyl) ethyltrichlorosilane. The sulfona Less