Lin Ching-Erh, Cheng Hsu-Tun, Fang I-Ju, Liu Yu-Chih, Kuo Chia-Ming, Lin Wann-Yin, Lin Chen-Hsing
Department of Chemistry, National Taiwan University, Taipei, Taiwan.
Electrophoresis. 2006 Sep;27(17):3443-51. doi: 10.1002/elps.200500658.
Strategies for simultaneous enantioseparations of three catecholamines (DL-norepinephrine, DL-epinephrine, and DL-isoproterenol) and three structurally related compounds (DL-octopamine, DL-synephrine, and DL-norephedrine) by CZE using sulfated beta-CDs as chiral selectors were investigated. Four different separation modes were attempted: (I) using randomly sulfate-substituted beta-CD (MI-S-beta-CD) at relatively low concentrations in a high-concentration phosphate buffer at low pH in the normal polarity mode, (II) using MI-S-beta-CD at high concentrations at low pH in the reversed polarity mode, (III) using MI-S-beta-CD at moderately high concentrations in a phosphate buffer at neutral pH in the normal polarity mode, and (IV) using the single isomer heptakis(2,3-dihydroxy-6-O-sulfo)-beta-CD (SI-S-beta-CD) at low to moderately high concentrations in a high-concentration BGE at low pH in the normal polarity mode. Among them, enantioseparation of these cationic solutes was best achieved under the conditions of mode (II). In mode (II) and mode (III), temperature is an important factor affecting the enantioresolution of norepinephrine. In mode (I) and mode (IV), the use of a high-concentration BGE (150-200 mM) is crucial for effective enantioseparation of these cationic solutes with sulfated beta-CDs. Comparative studies of enantioseparations of these cationic solutes with MI-S-beta-CD and SI-S-beta-CD reveal that the sulfate substituents of MI-S-beta-CD located at the C(2)- position interact strongly with the diol moiety of catecholamines.
研究了以硫酸化β-环糊精为手性选择剂，通过毛细管区带电泳同时对三种儿茶酚胺（DL-去甲肾上腺素、DL-肾上腺素和DL-异丙肾上腺素）及三种结构相关化合物（DL-章鱼胺、DL-辛弗林和DL-去氧麻黄碱）进行对映体拆分的策略。尝试了四种不同的分离模式：（I）在低pH值的高浓度磷酸盐缓冲液中，以正常极性模式使用相对低浓度的随机硫酸化β-环糊精（MI-S-β-CD）；（II）在低pH值下以反相极性模式使用高浓度的MI-S-β-CD；（III）在中性pH值的磷酸盐缓冲液中，以正常极性模式使用中等高浓度的MI-S-β-CD；（IV）在低pH值的高浓度背景电解质中，以正常极性模式使用低至中等高浓度的单异构体七（2,3-二羟基-6-O-磺基）-β-环糊精（SI-S-β-CD）。其中，在模式（II）的条件下，这些阳离子溶质的对映体拆分效果最佳。在模式（II）和模式（III）中，温度是影响去甲肾上腺素对映体拆分的重要因素。在模式（I）和模式（IV）中，使用高浓度的背景电解质（150 - 200 mM）对于用硫酸化β-环糊精有效拆分这些阳离子溶质至关重要。用MI-S-β-CD和SI-S-β-CD对这些阳离子溶质进行对映体拆分的比较研究表明，MI-S-β-CD位于C(2)位置的硫酸酯取代基与儿茶酚胺的二醇部分强烈相互作用。
