共查询到19条相似文献,搜索用时 578 毫秒
1.
β-环糊精聚合物膜拆分氨基酸对映体 总被引:25,自引:2,他引:23
环糊精(CD)具有亲水的外围及憎水的内腔,在溶液中可与许多有机物形成包合物,并对其形状、体积与极性呈现选择性^[1]。通过化学修饰引入新的识别基团,可使CD具有更高的结合选择性,即多重分子识别^[2]。CD及其衍生物可用作气相色谱固定相、液相色谱固定相和流动相手性添加剂、毛细管电泳溶剂介质分离各种光学异构体,但作为膜分离材料来拆分手性化合物的有关报道却很少^[3]。本文将氨基取代的环糊精子分子共价键合于聚乙烯醇上,制得带有环糊精基团的聚合物膜,并用此膜拆分了某些消旋氨基酸。 相似文献
2.
新手性源5-(l-孟氧基)-3-溴-2(5H)-呋喃酮的合成和结构 总被引:7,自引:0,他引:7
文中深入研究了5-(l-孟氧基)-3-溴-2(5H)-呋喃酮新手性源(5a)的合成方法及其不对称合成反应。5a不仅制备方法简便,光学纯度单一,而且它作为稳定的Michael受体,可与碳、氧、氮、硫等不同的亲核试剂发生串联的Michael加成/分子内亲核取代反应,制备得到含有多个手性中心的双环[3.3.0^3^,^7]-5-辛烯类化合物、双环[3.1.0^3^,^5]-己烷类化合物和螺-环丙烷类化合物。本文报道了该手性呋喃酮5a的合成和构型测定。 相似文献
3.
针对国际上对金属配合物同DNA间作用机量的争议,采用分子模拟手段在MM2力场下,搭建并优化了手性金属配合物△,Λ-[Co(phen)2tpphz]^3+与B-DNA[d(GTCGATCGAC)2]的模型,继而对其相互作用进行了模拟,得出的结论是:对所采用的B-DNA片断,该金属配合物有明显的立体选择性△型配合物从小沟插入占明显优势,而且,总体来看,从AT区插入更易进行。 相似文献
4.
针对国际上对金属配合物同DNA间作用机量的争议,采用分子模拟手段在MM2力场下,搭建并优化了手性金属配合物△,Λ-[Co(phen)2tpphz]^3+与B-DNA[d(GTCGATCGAC)2]的模型,继而对其相互作用进行了模拟,得出的结论是:对所采用的B-DNA片断,该金属配合物有明显的立体选择性△型配合物从小沟插入占明显优势,而且,总体来看,从AT区插入更易进行。 相似文献
5.
6.
手性3-溴-2(5H)-呋喃酮的合成及其串联的不对称Michael加成 反应的研究 总被引:2,自引:0,他引:2
研究了新的手性试剂,5-(l-孟氧基)-3-溴-呋喃酮(5a)的合成及其与亲核性醇发生的串联不对称双Michael加成/分子内亲取代反应。通过此反应,一举生成了四个新的手性中心,得到了一般方法难以合成的含有多个手性中心的丁内酯并螺-环丙烷类化合物8a~8d。详细报道了8a~8d的合成方法以及它们的[α]、IR、UV、^1^HNMR、^13^CNMR、MS、元素分析等结构分析数据。此不对称双Michael加成/分子内亲核取代反应可以为某些新的光学活性螺-环内丙烷类化合物以及某些复杂结构的分子提供合成策略。 相似文献
7.
三唑烯醇手性识别的分子力学研究 总被引:2,自引:0,他引:2
近十几年来 ,解决不同类型手性化合物的分离是手性色谱发展的前沿领域 [1~ 3] ,对手性识别机理的研究也逐渐引起重视 [4 ,5] ,但由于缺乏手性固定相和手性化合物分子复合体的单晶数据 ,有关手性分离机理的通用定量解释方法很不完善 .采用分子模型设计和理论计算方法 ,研究 CSPs与手性化合物复合体的三维结构性质 ,不仅易于获得 CSPs与 R-体、S-体之间能量的差值 ,而且能直观地得出手性识别发生的位置、作用力的性质及其大小 ,这对于新型 CSPs的设计 ,药物动力学研究和药物分子设计具有十分重要的意义 .本文利用分子力学方法研究了手性… 相似文献
8.
9.
10.
环糊精超分子体系的手性识别研究──D,L-色氨酸对映体的手性识别荧光分析法 总被引:1,自引:0,他引:1
超分子体系的分子识别,甚至手性识别特征对从分子水平上模拟生物功能,研究生物体内各种信息的传递及酶与底物相结合过程等具有重要的理论和实际意义,它的应用也为发展特异性、专一性、选择性高的分析方法提供了广阔的前景[1,2].环糊精是不同个数的吡哺型葡萄糖单元通过a-1,4糖音键联接而成的筒状低聚糖,其手性内腔早已引起人们的注意,并成功地应用在对映体化合物的色谱手性拆分、模拟酶反应和选择性催化反应等领域[3].本文研究首次发现D,L-色氨酸对映体在外环糊精存在下呈现显著不同的手性包络差异,这种差异与酸度和温度密切… 相似文献
11.
分子烙印手性固定相分离过程热力学研究 总被引:8,自引:0,他引:8
考察了温度对分子烙印固定相手性分离的影响,计算了手性分离过程中的热力学参数.结果表明,分子烙印手性固定相的分离过程为焓控制过程.随着温度的升高,样品的容量因子降低,手性选择因子α减小.样品与分子烙印固定相的作用力包括非特异作用力和特异作用力,只有特异作用力的差值才是手性分离的本质.分子烙印产生的空穴对热力学参数有较大的影响,烙印分子与烙印空穴的匹配性最好,烙印空穴对烙印分子的结合在能量和构型上都是有利的. 相似文献
12.
Shabi Abbas Zaidi Seung Mi Lee Zeid A. AL Othman Abdullah M. AL Majid Won Jo Cheong 《Chromatographia》2011,73(5-6):517-525
Some acidic chiral templates were used to prepare open tubular (OT) molecule imprinted polymer (MIP) capillary columns to explore the effects of molecular structures of templates on chiral recognition capabilities and to verify the feasibility of the general MIP preparation protocol introduced in the previous study. The templates are phenyl carboxylic acids and their derivatives. Optimization was carried out for chiral separation of template enantiomers for each MIP column through varying pH and composition of eluent. It was found that the preparation protocol can be successfully applied for the appropriate templates with functional groups fulfilling the three-points interaction rule. The chiral separation performances were quite satisfactory for MIPs of such templates although they are yet inferior to the separation performances of the MIP columns fabricated with the templates of profen drugs (2-arylpropionic acids with a large substituent on the phenyl ring). Subtle variations of the template molecular structures have been found to be critical to enhance chiral recognition ability of the resultant MIP column. 相似文献
13.
Zhang G Hong Z Chai Y Zhu Z Song Y Liu C Ji S Yin X Wu Y 《Chemical & pharmaceutical bulletin》2007,55(2):324-327
The purpose of this paper was to study the chiral recognition mechanism of enantioseparation of adrenaline and its analogues using capillary electrophoresis. The enantiomeric separation of adrenaline and its analogues has been developed using beta-cyclodextrins as the chiral selectors. All the tested compounds were separated under the same experimental conditions to study the chiral recognition mechanisms, using a low-pH buffer (50 mM Tris buffer at pH 2.5). By means of molecular docking the inclusion course between beta-cyclodextrins and enantiomers was investigated and thus the interaction energy was obtained by molecular mechanics calculations. The results suggest that the difference in interaction energy for the side chain part is most likely responsible for enantiomeric separation. 相似文献
14.
Liangzhao Cai Mengyao Xue Jia Lun Shuang Li Jia Yu Xingjie Guo 《Electrophoresis》2020,41(24):2092-2101
The enantioseparation of eight psychoactive drugs has been firstly performed on a coated cellulose-based chiral stationary phase (Chiralcel OJ-H). To obtain optimum separation conditions, the influences of alcohol modifiers and basic/acidic additives have been studied. As a result, except for the partial separation of oxybutynin enantiomers, the other seven drug enantiomers, including mirtazapine, sulpiride, promethazine, citalopram, oxazepam, donepezil, and cyamemazine, have been completely separated. Additionally, for gaining a better insight into the chiral recognition mechanisms, molecular docking was carried out using the Autodock software. Herein, binding energy and conformations of the chiral stationary phase complexes were provided, and it was found that the distinction in enantiomeric conformation determined the number and strength of intermolecular interactions between analytes and chiral stationary phase which resulted in the difference in binding energies of two enantiomers, and ultimately led to the different migration. These modeling results were in accordance with the observed enantioseparation results in high performance liquid chromatography experiments. At last, chiral separation mechanisms have been discussed in detail, and it has been confirmed that hydrogen bond, π–π, hydrophobic interactions, and some special interactions synergistically contributed to the enantioseparation of psychoactive drugs. 相似文献
15.
16.
Tadashi Ema 《Journal of inclusion phenomena and macrocyclic chemistry》2012,74(1-4):41-55
Chiral synthetic macrocyclic receptors that can achieve chiral discrimination by NMR spectroscopy and/or chiral separation by HPLC are overviewed. Synthetic macrocycles introduced here include crown ethers, calixarenes/calixresorcinarenes/calixpyrroles, macrocyclic amides/amines, and porphyrins. These macrocyclic frameworks are advantageous because intermolecular interactions can take place effectively, such as the ion–dipole interactions in crown ethers, the CH/π and π–π interactions in calixarenes, hydrogen bonding and salt formation in macrocyclic amides and amines, and π–π stacking and metal coordination in porphyrins. Additional functional groups on the periphery of the macrocyclic platforms not only make the whole molecule chiral but also act as the interaction sites. Chiral macrocyclic receptors can show a high degree of chiral recognition/discrimination by using the peripheral functional groups as well as the macrocyclic skeletons (preorganization). Both hosts and guests are shown in the figures to quickly overview the molecular recognition scope of synthetic macrocyclic receptors in chiral analysis and separation. 相似文献
17.
手性药物通过与生物体内生物大分子之间的手性匹配与分子识别来发挥药理作用。两个对映体与体内手性环境相互作用的不同导致每个对映体表现出不同的药理活性、代谢过程、代谢速率及毒性等药代动力学特征。因此发展手性药物的拆分方法,对于手性药物的开发和生产过程的质量监控具有重要意义。分子印迹聚合物(MIPs)是以目标分子作为模板而制备的高分子聚合物,它具有特定的空间分子结构和官能团,对目标分子具有高度的特异性识别能力。基于该特点,MIPs非常适合于手性药物的拆分和纯化。毛细管电色谱(CEC)可同时基于毛细管电泳和液相色谱的分离机理对目标物进行分离,因此具有高分离效率和高选择性的特点。将MIPs材料作为CEC的固定相,可将这两种技术的优势结合,从而实现对手性药物的高效拆分。MIPs材料在1994年首次应用于CEC手性拆分,此后该研究领域开始获得关注和发展。MIPs材料主要通过4种模式在CEC中实现手性拆分,分别是作为开管柱、填充柱和整体柱的固定相以及分离介质中的准固定相。该综述以这4种模式作为分类基准,根据MIPs制备所需的材料和分离对象对其在CEC手性拆分中的应用进行了总结,揭示了MIPs在CEC手性拆分中的潜力,同时评述了这4种模式各自的优势与不足,并对将来MIPs在CEC手性拆分中的发展进行了展望。 相似文献
18.
正相条件下温度和流速对衍生化环糊精键合手性高效液相色谱固定相立体异构体选择性的影响 总被引:5,自引:0,他引:5
合成了苯基氨基甲酸酯衍生化的β-环糊精键合固定相,9个α-氨基膦酸酯类化合物首次在环糊精类固定相上进行了有效拆分,研究了温度和流速对异构体选择性的影响,讨论了可能的手性识别机理. 相似文献
19.
Recently, molecular imprinting technology has fleetly developed for applications in different fields. It shows great potential in sensor design, drug delivery, chromatography separation, catalysis, chiral synthesis, and especially in the molecular recognition field. In this work, a cubic model of a hydrogel network was developed and an infinite hydrogel backbone network was constructed for molecular dynamics simulation. The water structure and water-polymer interaction was investigated from the radial distribution function and the viewpoint of the hydrogen-bonding system. It is found that the hydrogen bonds between polymer and water strongly depress the diffusion of water molecules and enhance the structure of water in the system. The greater the network mesh size of the polymer, the weaker the structure of the water. The decreasing of the density of hydrogen bonds between polymer and water is the major factor that leads to the weakening of water structure. 相似文献