【作者】 叶燕；

【导师】 施介华；

【作者基本信息】 浙江工业大学 ， 药物分析， 2010， 硕士

【摘要】 采用气相色谱法在全甲基β环糊精手性色谱柱(PMBCD)和(2,3二O甲基6 O叔丁基二甲基硅基)β环糊精(MeTBDMSβCD)上考察了溶质结构、柱温及固定相结构等对羧酸仲丁酯对映体分离的影响;结果表明,随着羧酸仲丁酯中羧基基团的增大,羧酸仲丁酯对映体的分离因子(α)和分离度(Rs)先增大后减小,乙酸仲丁酯对映体分离效果最好。而且,羧酸仲丁酯对映体的容量因子(k′)和分离因子(α)的对数与羧基中烷基基团参数π和Es间具有良好的线性关系。随着柱温升高,羧酸仲丁酯对映体的容量因子(k′)、分离因子(α)和分离度(R)也随之减小。对映体在全甲基β环糊精手性色谱柱的分离效果好于在(2,3二O甲基6 O叔丁基二甲基硅基)β环糊精手性色谱柱上。通过对对映体分离过程中的热力学参数的计算,探讨光学异构体分离过程的驱动力;结果表明羧酸仲丁酯对映体在β环糊精衍生物手性色谱柱(CyclodexB和CycloSilB)上的分离过程是一个焓驱动过程并存在着焓熵补偿关系。运用量子力学PM3方法模拟乙酸仲丁酯((R/S) BAA)与全甲基β环糊(PMBCD)的主客相互作用,探讨(R/S) BAA在PMBCD上的手性识别机理。量子化学PM3方法模拟和热力学参数计算结果表明,客体(R/S) BAA对映体与主体PMBCD形成的最稳定结合物的几何结构明显不同,(R/S) BAA分子中手性碳(C*)接近葡萄糖甙单元中2 ,3位手性碳,(R) BAA与PMBCD结合比(S) BAA与PMBCD结合更紧密,(R) BAA PMBCD结合能小于(S) BAA PMBCD,前者比后者更稳定。这种模拟结果与气相色谱对映选择性结果完全一致。包结前后主体和客体分子的某些结构和性质,如主体腔体大小及形状、客体分子形变能发生了较为明显的变化,说明在环糊精与(R/S) BAA对映体的结合过程中,范德华作用对主客体包结物的稳定性及结构性质存在重要的影响。运用量子力学PM3方法模拟乙酸仲丁酯((R/S) BAA)与(2,3二O甲基6 O叔丁基二甲基硅基)β环糊精(MeTBDMSβCD)的主客相互作用,探讨(R/S) BAA在MeTBDMSβCD上的手性识别机理。量子化学PM3方法模拟和热力学参数计算结果表明,客体(R/S) BAA对映体与主体MeTBDMSβCD形成的最稳定结合物的几何结构明显不同,其中(R) BAA MeTBDMSβCD包结物中,客体分子整体相对垂直环糊精糖苷氧所成平面,(S) BAA MeTBDMSβCD包结物中,客体分子明显倾斜,与环糊精糖苷氧所成平面约成30°角。(R/S) BAA MeTBDMSβCD中,客体分子完全被包结在MeTBDMSβCD空腔内,且亲水基团均朝向环糊精窄口端, (R) BAA MeTBDMSβCD结合能小于(S) BAA MeTBDMSβCD,前者比后者更稳定。更多还原

【Abstract】 The separation of enantiomers of sec butyl carboxylicates on theβcyclodextrin derivatives chiral column had been studied by gas chromatography. The effect of sec butyl carboxylicates structure and column temperature on the separation of enantiomers of sec butyl carboxylicates had been investigated. On the other hand, the thermodynamic parameters in the process of separation of enantiomers on theβcyclodextrin derivatives chiral column (Cyclodex B and CycloSil B) were determined in order to discuss driven power in the process of separation of optical isomers. Chiral recognization mechanism of (R/S) BAA enantiomers on PMBCD was investigated. The experiment results showed that the separation factor (α) and separation degree (Rs) of sec butyl carboxylicates decreased when the chain size of carboxyl group increase. The separation degree of enatiomers of sec butyl acecate was best. There is excellent linear relationship between the logarithms of capacity factor (k′) and separation factor (α) of enantiomers of sec butyl carboxylicates and alkyl group parameters on the carboxyl group such asπand Es. And, the capacity factor (k′), the separation factor (α) and separation degree (Rs) of the enatiomers of sec butyl carboxylicates decreased with the increasing of the column temperature. It was demonstrated that the separation of enatiomers of sec butyl carboxylicates on theβcyclodextrin derivatives chiral column (Cyclodex B and CycloSil B) was enthalpy driven process and there was enthalpy entropy compensation.Host guest complexation of permethlatedβcyclodextrin (PMBCD) and with enantiomers of sec butyl acecates ((R/S) BAA) was simulated by Quantum Mechanics PM3 method. The Modeling results showed the stabilization complexation structures which formed with (R/S) BAA enantiomers and PMBCD were different. The stabilization energy of (R) BAA PMBCD complex was less than that of (S) BAA PMBCD. The chiral carbon in BAA for (R/S) BAA PMBCD complexes was closed to C(2) and C(3) in glucose unit. The former is stabler than the latter. The results correspond to the experimental findings from enantioselective gas chromatography.The structures and properties of the houst and the guest before and after inclusion,such as the size and shape of the houst cavity, the deformation energe of the guest molecular can be more significant changes, indicating that in the process of inclusion with CDs and (R/S) BAA enantiomers, the Van der Waals interaction plays an important role on the host guest inclusion process.更多还原