β-环糊精及其衍生物与TNS超分子包络物研究

环糊精(Cyclodextrin,简称CD)又名沙丁格糊精(Schardinger dextrin),它们是由环糊精葡萄糖基转移酶(CGT)作用于淀粉所产生的一组以α-1,4糖苷键结合的环状低聚糖.其中最常用的是β-CD.作为有序介质的一种,其显著结构特征是存在一个筒状立体手性疏水空腔[1].     

杀鼠剂溴敌隆和环糊精的超分子作用及分析应用

利用光谱法研究了β-环糊精(β-CD)与杀鼠剂溴敌隆(BRD)的超分子作用, 结果发现二者可形成1∶1的超分子包络物, 室温下包络常数为357.7 L/mol. 通过相关数据和对4-羟基香豆素的对比试验初步探索了溴敌隆和β-环糊精的包络模式, 应该是溴敌隆结构中的疏水基团4-羟基香豆素母环或者溴代联苯基进入了β-环糊精的疏水空腔之中从而形成超分子包络物. 实验还观察到这种包络作用可以大大增敏溴敌隆的荧光. 据此, 建立了水溶液中测定溴敌隆的荧光光度法并考察了影响二者包络作用的因素. 在优化的条件下, 线性范围为8.0×10-8～1.0×10-5 mol/L, 检出限2.5×10-8 mol/L. 该方法用于渠水中微量溴敌隆的测定, 回收率为92.2%～109.4%.     

荧光各向异性法研究环糊精包络物

推导了用荧光各向异性法测定环糊精包络物平衡结合常数的方程式,并用于测定芘-β-环糊精包络物的结合常数,获得了满意的结果,依据推得的方程式并结合各向异性～环糊精浓度曲线讨论了环糊精包络物存在形式及主-客体作用方式,预计了以蔡衍生物为配体的金属离子分析方法应用β-环糊精的可能性。     

荧光光谱法测定环糊精包络物的形成常数

环糊精(Cyclodextrin,简写为CD)是由淀粉经酶促水解而形成的一种筒形低聚葡萄糖,单体间以α-1,4糖甙键相联。常见的有α-,β-和γ-CD三种,其中葡萄糖单体数分别     

超分子中主体热分解行为的多样性分析——残存态环糊精的热分解

指出了只有在主-客体超分子化学中才能出现的主体热分解行为多样性现象, 提出了所谓的残存态主体(survived host)的概念. 残存态主体意指主-客体超分子失去客体后的产物, 它是由分子间弱相互作用所引起的主-客体包合现象的有力佐证. 以残存态环糊精(survived CD)为着眼点, 仔细比较了游离态CD、CD包合物即包结态CD与残存态CD的热分解行为差异性, 据此指出了有关文献在进行包结态CD热分解动力学计算时, 将残存态CD当成包结态CD来处理的一个概念错误.     

β-CD与Triton X-100超分子包络物的研究

通过荧光光谱法和^1HNMR研究了水溶液中β-环糊精（β-CD）与TritonX-100形成的超分子包络物．结果表明,在溶液中β-CD与TritonX-100形成了1：1二元包络物．25℃时超分子包络物的表观稳定常数为（3．04±0．22）×10^4L／mol．TritonX-100疏水性端包结在β-CD空腔内．     

电化学方法研究环糊精-硝基氯苯包络物

在KCl水溶液介质中，以单扫示波极谱及循环伏安法研究了硝基氯苯及其与各种环糊精包络物的电化学行为。硝基氯苯与β-环糊精、羟乙基-氨基-6去氧-β-环糊精、羟丙基-β-环糊精、羟乙基-β-环糊精的包络比均为1：1。测定了不同温度下各包络物的包络常数。通过测量溶液的热力学参数ΔH、ΔS、ΔG，讨论了包络现象。     

环糊精及其包络物的分子力学研究

本文用分子力学方法研究了环糊精及其包络物的性质, 探讨了包络过程及其驱动力, 与电化学实验结果对比获得一致性结伦。     

环糊精超分子组装体的研究进展

环糊精是由若干个D-吡喃葡萄糖单元通过α-1,4-糖苷键连接而成的环状低聚糖,具有一个亲水性的外表面和一个疏水性的空腔。利用主客体相互作用,环糊精及其衍生物能够选择性地与大小匹配的疏水性客体分子形成各种超分子包合物。本文概述了环糊精的结构与性质,并介绍了近年来国内外以环糊精为基础的纳米粒子、水凝胶等超分子组装体的设计原理、作用机制、刺激响应及应用特点,并对环糊精超分子组装体的前景进行了展望。     

环糊精-聚合物超分子材料的研究进展

环糊精是由若干D-吡喃葡萄糖单元环状排列而成的圆锥状筒形分子,具有中空内孔结构.研究表明:当长链高分子的分子尺寸与环糊精内径相匹配时,高分子可作为客体分子串入环糊精的中空内孔中自聚集成为一种独特的超分子包结物.本文从环糊精的结构性质、环糊精-聚合物超分子的复合机理、客体聚合物的种类、以及复合物的应用领域四个方面全面综述了近年来有关环糊精和高聚物包结物的相关研究现状.并在最后展望了环糊精-聚合物超分子未来的发展方向.     

水溶液中环糊精包结物的包结常数的测定方法

环糊精（CD）是由6，7，8个葡萄糖基构成的环状化合物，分别叫做α、β、γ-CD，它们具有“外亲水，内疏水”的独特性质，可以与多种物质形成包结物，而改变物质的特性，因而被广泛应用于各行各业中，在以往研究的基础上，总结了多种测定环糊精包结常数的方法，以便能更好地研究并开发利用具有极大潜力的环糊精。     

Formation of Inclusion Complexes between Cyclodextrins and Carbaryl and Characterization of the Complexes

The solubility of carbaryl increased with increasing concentrations of-CD, G₂--CD, and M--CD. The result suggests theformation of soluble inclusion complex. Solubility increase was highestin M--CD-carbaryl, being 18.4 fold higher than that of carbaryl when 100 mM M--CD was used. The apparent formation constant for the complex calculated from phase solubility diagram was 223.18 M^-1. The preparation of the complex in solid form for characterization was successful by kneading andfreeze-drying. The DSC curves for kneading and freeze-drying mixture didnot show the endothermic peak characteristic of carbaryl, but a small new endothermic peak was observed. FTIR analysis showed a shift of the major peak of carbonyl group in carbaryl molecule from 1717 to 1744 and 1734 cm^-1 in kneading and freeze-dried mixtures, respectively. M--CD-carbaryl complex demonstrated higher dissolution rate, higher thermal and UV stability but lower toxicity than its parent carbaryl compound.     

Spectroscopic Study of the Inclusion Complexes of Phenylbutazone and Oxyphenbutazone with Cyclodextrins in Polar Reaction Media

The formation of inclusion complexes of -, -, hydroxypropyl-- (HP--) and -cyclodextrins with phenylbutazone and oxyphenbutazone has been studied in aqueous buffer solution (pH 7.5 and 0.1 mol dm^-3 NaCl), dimethylsulfoxide, and 25, 50 and 75% dimethylsulfoxide/water mixtures. These complexation reactions have been followed by UV electronic absorption spectroscopy. In addition, 1D and 2D ¹H NMR spectra were recorded to obtain structural information about the inclusion complexes formed in solution; 136 binding constant values were determined at five different temperatures (288, 293, 298, 303 and 310 K) from the electronic absorption data and, from these H_binding and S_binding values were obtained. At the studied cyclodextrin and guest concentration ranges, 1 : 1 inclusion complexes were detected. Only in three cases were 1 : 2 complexes detected, those of phenylbutazone and oxyphenbutazone with -cyclodextrin in aqueous, and oxyphenbutazone with hydroxypropyl--cyclodextrin in 75% dimethylsulfoxide/water solutions.     

Synthesis of Supramolecular Nanocapsules Based on Threading of Multiple Cyclodextrins over Polymers on Gold Nanoparticles

The CD ' s stuck : Poly(ethylene glycol) chains anchored onto gold nanoparticles (AuNPs) are threaded by multiple α‐cyclodextrin (α‐CD) rings to form a supramolecular outer layer composed of pseudopolyrotaxane columns perpendicular to the nanoparticle surface. Capping the polymer ends confines α‐CD on the nanoparticle surface, cross‐linking the α‐CD rings and then removing the AuNP cores produces supramolecular nanocapsules.

     

环糊精及其衍生物的超分子晶体结构研究进展

本文对近年来有关环糊精、环糊精衍生物以及它们与各类客体组装成的超分子包合物的晶体结构研究进行的简要概述。     

气相中环糊精与甘氨酰-苯丙氨酰-苯丙氨酸和甘氨酸三肽非共价复合物的质谱研究

为了探索环糊精和寡肽的非共价相互作用, 一定化学计量比的α-, β-, γ-环糊精(CD)分别和甘氨酸三肽(GGG)、甘氨酰-苯丙氨酰-苯丙氨酸三肽(GFF)在室温下反应达到平衡并用正离子模式质谱检测. 实验结果显示GGG, GFF均可以和α-, β-, γ-CD生成1:1配合比的非共价复合物. 碰撞诱导解离实验进一步验证了α-, β-, γ-CD与GGG, GFF非共价复合物的形成. 质谱滴定法测得的结合常数结果表明环糊精和两种三肽形成非共价复合物的结合强度均按照γ-, β-, γ-CD的次序逐渐增大. GGG和α-, β-, γ-CD复合物的结合常数分别为2799.96, 2528.73, 1697.11 L·mol^-1, GFF和α-, β-, γ-CD复合物的结合常数分别为2773.94, 2134.03, 1330.68 L·mol^-1. 对于α-, β-或γ-CD, 含有苯基的GFF+CD复合物的结合强度要小于相应的脂肪族的GGG+CD复合物, 表明虽然在气相GFF+CD复合物的构象与溶液中的构象有所变化, 但是苯基仍然参与和环糊精疏水腔体的键合作用.     

Kinetic Studies on the Thermal Dissociation of β-Cyclodextrin·Ethyl Benzoate Inclusion Complexes

The stability of β-cyclodextrin·ethyl benzoate·6H₂O(β-CD·C₆H₅COOC₂H₅·6H₂O) was investigated by TG and DSC. The mass loss takes place in three stages: the dehydration occurs at 50-120°C; the dissociation of β-CD·C₆H₅COOC₂H₅occurs at 200-260°C; the decomposition of β-CD begins at 280°C. The kinetics of the dissociation of β-CD·C₆H₅COOC₂H₅in a dry nitrogen flow was studied by means of thermogravimetry both at constant temperature and linearly increasing temperature. The results show that the dissociation of β-CD·C₆H₅COOC₂H₅is dominated by a three-dimensional diffusion process (D₃). The activation energy E is 116.19 kJ mol^-1and the pre-exponential factor A 6.5358·10⁹min^-1. Cyclodextrin is able to form inclusion complexes with a great variety of guest molecules, and the studies focus on the energy of binding between cyclodextrin and the guest molecule. In this paper, the β-cyclodextrin·ethyl benzoate inclusion complex was studied by fluorescence spectrophotometry and infrared absorption spectroscopy, and the results show that the stable energy of inclusion complexes of β-CD with weakly polar guest molecules consists mainly of van der Waals interaction. This revised version was published online in July 2006 with corrections to the Cover Date.     

Fluorescent Vesicular Particles Assembled by Inclusion Complexes Between Cyclodextrins and BPB

Vesicular particles based on inclusion complexes between BPB and γ-HB-β-CDs were prepared and characterized for the first time. The morphologies and sizes were confirmed by transmission electron microscopy (TEM), scanning electron microscope (SEM), and dynamic light scattering (DLS). Particularly, these vesicular particles exhibiting clearly fluorescent dots observed by laser confocal scanning microscopy (LCSM) could be alternative candidates as fluorescent probes and labels being applied to cellular staining, labeling, bio-mimicking and drug delivery. The ultraviolet, fluorescence, and nuclear magnetic resonance (NMR) measurements confirmed the existence of stable 1:1 BPB-γ-HB-β-CD complexes in the system. The vesicular particles were assumed to be constructed by orderly self-aggregates of these inclusion complexes.     

过渡金属膦配合物在硅氢化反应中的应用研究

过渡金属膦配合物在有机合成和催化反应中的应用非常广泛, 大量含膦杂原子配体被设计合成, 利用其特定的配位能力, 和过渡金属配位成过渡金属膦配合物, 并测试其对特定有机化学反应的催化性能. 硅氢加成反应是有机硅化学中的重要反应, 多种过渡金属包括铂、钯、铑、钌等的膦配合物对于硅氢加成反应均有催化活性. 综述了近几年来过渡金属膦配合物在硅氢加成反应中的应用进展.     

基于环糊精包结络合作用的大分子自组装

本文综述了基于环糊精包结络合作用的大分子自组装的研究进展,包括：（1) 线型、梳型、多臂星型或超支化聚合物与环糊精或其二聚体自组装形成多聚轮烷（分子项链）、多聚准轮烷、双多聚（准）轮烷、分子管、双分子管、超分子凝胶及其应用;（2）桥联环糊精与桥联客体分子自组装制备线型或超支化超分子聚合物;（3）温度、pH值、光及客体分子刺激响应智能体系; （4) 通过亲水性的环糊精线型均聚物与含金刚烷的疏水性聚合物之间的包结络合作用来制备高分子胶束及其空心球等。