Understanding nonlinear composition dependency of enantioselectivity in chiral separation using mixed micelle
Understanding nonlinear composition dependency of enantioselectivity in chiral separation using mixed micelle
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DOI：
10.1016/j.jcis.2022.07.086
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发表时间：
2022-07-22
影响因子：
9.9
通讯作者：
Suzuki，Nozomu
中科院分区：
文献类型：
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作者：
Suzuki，Nozomu
假设超分子的手性和非手性结构单元的混合物表现出有趣的合作现象，由手性性质的非线性组成依赖性表示。然而，混合胶束的对映选择性的非线性组成依赖性还没有得到很好的理解。据推测，深入了解，可以通过仔细调查的组成依赖性的property.ExperimentsIn这项工作中，非手性和chiralN-酰基氨基酸的混合胶束的胶束电动色谱（MEKC）的对映体选择性的非线性组成依赖性被发现。通过毛细管电泳、圆二色谱（CD）、表面张力测定和荧光光谱等方法对该体系的非线性机理进行了研究，发现引起该体系非线性的机理主要有四种：（i）表面活性剂之间的协同作用和拮抗作用，（ii）手性向非手性表面活性剂的手性转移，（iii）保留因子的差异，（iv）表面活性剂与非手性表面活性剂之间的相互作用，（iv）表面活性剂与非手性表面活性剂之间的相互作用。和（iv）手性和非手性表面活性剂的协同手性识别。临界胶束浓度（CMC）和摩尔圆二色性的组成依赖性的调查表明，（i）和（ii）的影响是微不足道的。新推导的方程（iii）和（iv）显示，（iii）和（iv）有一个主要或中等的非线性对映选择性的影响。
HypothesisMixtures of chiral and achiral building blocks of supramolecules exhibit interesting cooperative phenomena, indicated by the nonlinear composition dependence of the chiral properties. However, the nonlinear composition dependence of the enantioselectivity of mixed micelles is not well understood. It was hypothesized that in-depth understanding can be achieved by carefully investigating the composition dependence of the properties.ExperimentsIn this work, the nonlinear composition dependence of the enantioselectivity was found for the mixed micelle of achiral and chiralN-acyl amino acids by micellar electrokinetic chromatography (MEKC). Capillary electrophoresis, circular dichroism (CD) spectroscopy, surface tension measurement, and fluorescence spectroscopy were used to investigate the mechanisms.FindingsFour mechanisms that could be causing the nonlinearity were investigated: (i) synergistic and antagonistic interactions of the surfactants; (ii) the chiral transfer from chiral to achiral surfactant; (iii) differences in the retention factor; and (iv) cooperative chiral recognition of the chiral and achiral surfactant. The investigation of the composition dependency of critical micelle concentration (CMC) and molar circular dichroism revealed that the effect of (i) and (ii) was negligibly small. The newly derived equations for (iii) and (iv) revealed that (iii) and (iv) have a major or medium effect on the nonlinear enantioselectivity.