共查询到20条相似文献,搜索用时 156 毫秒
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采用紫外分光光度法研究了两种壳层悬挂β-环糊精单元的两亲性超支化聚合物在缓冲溶液(25 ℃, pH=11)中的分子包合与识别行为. 结果表明, 两种聚合物具有来自环糊精单元和两亲性超支化聚合物的双重包合能力, 可分别与水溶性染料分子酚酞(PP)、甲基橙(MO)、有机小分子对硝基苯酚(p-NP)等3种客体分子发生单客体包合效应, 而且其包合能力强于单一的环糊精或两亲性超支化聚合物; 通过客体分子PP和MO证实了这两种聚合物还具有双重识别能力, 可以与PP和MO发生双客体包合效应. 相似文献
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超分子聚合物通常以非共价键作为构筑驱动力,其结构具有动态可逆的特点,在新型响应性聚合物材料中具有突出优势。环糊精可通过主客体识别作用与客体分子如二茂铁、偶氮苯、金刚烷、苯环等形成包合,以此构筑的超分子组装体展现出丰富的自组装-解组装特性、刺激响应性、较低的细胞毒性和较好的生物相容性,有望在药物/基因载体领域得到应用。本文从环糊精超分子聚合物的生物医用出发,着重对近年来环糊精超分子聚合物载体在药物控制释放、基因转染以及药物/基因共递送三方面的研究进展进行了总结和评述,并在此基础上展望了环糊精超分子聚合物的研究方向和发展趋势。 相似文献
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含有重金属离子和有机化合物分子的污水具有产生量大、难处理等特点,对生态环境和人类健康均有潜在危害。环糊精聚合物(CDPs)既保留了环糊精自身的空腔及空腔外多羟基结构特征,同时也结合了聚合物的结构稳定性、基团多样性等优势,在污染物处理方面得到了广泛应用与关注。本文详细介绍了CDPs作为吸附剂的两种经典制备方法——交联法和固载法,阐述了其近年来在吸附染料分子、重金属离子、酚类物质以及药物分子方面的应用,分析了其作为吸附剂对不同污染物的吸附机理,并对CDPs研究与应用的发展趋势进行展望。 相似文献
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合成了 8-羟基喹啉与β-环糊精的包合物, 通过X射线单晶衍射研究了它的晶体结构. 结果显示其不对称单元包含2个β-环糊精、1个8-羟基喹啉, 2个乙醇和30个水分子. 其中两个β-环糊精分子通过仲羟基间氢键以头对头的方式形成二聚体, 客体8-羟基喹啉被包合在此二聚体的中间区域, 分子平面与环糊精的大环平面平行, 形成了一个具有三明治夹心结构的包合物. 两个环糊精空腔各包合一个乙醇分子, 30个水分子分散在β-环糊精二聚体之间. 研究表明, β-环糊精二聚体的三明治区域是疏水的, 对于某些大小合适且具有平面构型的客体分子, 如8-羟基喹啉, 此三明治区域比β-环糊精空腔具有更强的包合能力, 这种新颖的包合方式是乙醇与8-羟基喹啉竞争包合的结果. 相似文献
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布洛芬与环糊精的主-客体相互作用 总被引:1,自引:0,他引:1
在298.15K下,用滴定式微量热法研究了布洛芬分别与α-、β、γ-环糊精在Tris-HCl缓冲溶液(pH=7.0)中的包合作用.实验测得了布洛芬.环糊精包合物的实验稳定常数、形成过程的标准焓变、标准吉布斯自由能变及标准熵变等热力学参数.结果表明:布洛芬与α-、β-肛环糊精的包合过程是焓、熵协同驱动的过程,而γ-环糊精与该药物包合则是熵驱动的.此外,B3LYP/6-31G*//PM3方法用来模拟布洛芬与环糊精的包合过程,计算结果表明布洛芬分子的憎水部分更易于从大口进入环糊精分子的空腔. 相似文献
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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。 相似文献
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Elizabeth Stubbs Moira Brown Anna Steele Cheng Song Todd Emrick 《Journal of polymer science. Part A, Polymer chemistry》2019,57(16):1765-1770
AB2 monomers present opportunities to conduct one‐pot syntheses of highly branched or “hyperbranched” polymers, which are known for their distinct physical and chemical properties relative to linear polymers. This paper describes the synthesis of a deoxybenzoin‐containing AB2 monomer and its use in step‐growth polymerization to prepare branched aromatic polyesters. Highly soluble deoxybenzoin polymers were obtained with degrees of branching reaching 0.36 and estimated molecular weights approaching 20 kDa. The phenolic chain ends of the polymer allowed for post‐polymerization modification by silylation and esterification chemistry. TGA and microscale combustion calorimetry revealed these novel aromatic polyesters to possess the critically important characteristics of flame‐retardant polymers, such as high char yield and low heat release. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1765–1770 相似文献
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超支化聚合物研究进展 总被引:26,自引:3,他引:23
超支化聚合物由于具有高度文化三维球状结构以及众多的端基,因此显示出与相应线型分子截然不同的性质,如低粘度、无链缠结和良好的溶解性.本文讨论了超支化聚合物的特性与表征,对合成超支化聚合物所用单体以及产物作了详细介绍,旨在引起对该领域的兴趣. 相似文献
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C.C. Rusa M. Rusa J. Peet T. Uyar J. Fox M.A. Hunt X. Wang C.M. Balik A.E. Tonelli 《Journal of inclusion phenomena and macrocyclic chemistry》2006,55(1-2):185-192
When guest polymers are threaded by host cyclodextrins (CDs) to form crystalline inclusion compounds (ICs), the included polymer chains are highly extended and separated from neighboring chains. This is a consequence of the stacking of the cyclic oligosaccharides, α-, β-, or γ-CD containing 6, 7, or 8 glucose units, respectively, which produces continuous narrow channels (~0.5–1.0 nm diameters), where the guest polymers are included and confined. Observations that illuminate several important aspects of the nano-threading of polymers to form polymer-CD-ICs are described. These include (i) the competitive CD threading of polymers with different chemical structures and molecular weights from their solutions containing suspended solid or dissolved CDs, (ii) the threading and insertion of undiluted liquid polymers into solid CDs, and (iii) suspension of polymer A or B-CD-IC crystals in a solution of polymer B or A and observation of the transfer of polymer B or A from solution to displace polymer A or B and form polymer B or A-CD-ICs, without dissolution of the CD-ICs. In addition, we report observations of polyolefins adsorbed on zeolites, where we believe the adsorbed polyolefin chains are actually threaded and absorbed into the interiors of the zeolite nano-pores, rather than adsorbed on the zeolite surfaces. All of the above observations were made to assist in answering the question “Why do randomly-coiling polymer chains in solution or the melt become threaded or thread into the nano-pores of dissolved or solid CDs and solid zeolites, where they are highly extended and segregated from other polymer chains?” Though still not fully able to answer this question, we are able to assess the importance of several factors that have been previously suggested to be important in the formation of CD-ICs with both polymer and small-molecule guests and to the nano-threading of polymers in general. In particular, the value in observations of the inclusion of guest polymers, as well as small-molecule guests, into solid CDs suspended in their solutions and in neat guest liquids were made apparent, because interactions between host CDs, between CDs and solvents, and between quests and solvents, which complicate and make understanding the formation of polymer-CD-ICs difficult, are either eliminated or can be independently varied in these experiments. 相似文献
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This account describes our research progress in recent years in the areas of the molecular recognition studies on modified cyclodextrins, including positively charged cyclodextrins, cyclodextrin derivatives with hydrophobic substituent, and dimeric cyclodextrins. Calorimetric titration and various spectrometric techniques were employed to determine the complex stability constants, as well as the thermodynamic parameters, for their inclusion complexation with diverse guest molecules. The results obtained have been discussed from the viewpoint of size/shape‐matching, induced‐fit, geometric compensation, and multiple recognition. Thermodynamically, the compensatory relationship between ΔH and TΔS was found to be exhibited in the inclusion complexation of modified cyclodextrin. 相似文献
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Isamu Uemasu Satoshi Kushiyama 《Journal of inclusion phenomena and macrocyclic chemistry》1994,17(2):177-185
The inclusion complexation of five volatile chlorinated hydrocarbons, i.e., chloroform, carbon tetrachloride, trichloroethylene, tetrachloroethylene, and monochlorobenzene, with branched cyclodextrins (CDs) such as monoglucosyl--CD and monomaltosyl--CD in aqueous solutions was examined. Their inclusion complexes were found to be very water soluble and the solubilities of the chlorinated hydrocarbons in aqueous solutions increased almost linearly or gradually with increasing concentration of the branched CDs. The amounts of the chlorinated hydrocarbons included in the branched CDs were well related to their molecular size and shape. In addition, the viability of application to pollution prevention is discussed. 相似文献
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The preparation of novel cationic β‐cyclodextrin polymers (CPβCDs) and its complexes with butylparaben and triclosan were reported in this paper. FT‐IR and two‐dimensional (2D) 1H–1H gradient correlated spectroscopy (gCOSY) NMR spectra confirmed that the antibiotics could be included inside the lipophilic cavities of CPβCDs. The water solubility of the antibiotics was improved significantly after inclusion with CPβCDs. The results also suggest that it was easier for butylparaben, which had relatively small molecular size, to form the complexes with CPβCDs than triclosan. Due to the targeting effect after the inclusion with cationic CPβCDs, the anti‐microbial activity of butylparaben was also enhanced substantially. However, similar improvement was not obvious for triclosan.
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Synthesis of Cyclic Glycerol Ether Cyclodextrin Derivatives and Investigation of their Binding Properties with Drugs 总被引:1,自引:0,他引:1
Már Másson Josef Pitha Thorsteinn Loftsson 《Journal of inclusion phenomena and macrocyclic chemistry》1999,33(4):459-467
Epichlorohydrin was reacted with cyclodextrins to form the non-cyclic and cyclic glycerol ethers of - and -cyclodextrin (abbreviated as glyc-CD). Cyclic substitution extends the cyclodextrin cavity in a way that is as rigid and non-polar as the cavity of the parent cyclodextrin. Derivatives with extended cavities should better accommodate large or odd shaped molecules. The binding of drugs to the new cyclodextrin derivatives was investigated, through degradation rate studies and solubilization studies, and compared to that of -cyclodextrin, -cyclodextrin and hydroxypropyl--cyclodextrin. The inclusion binding of small molecules such as acetazolamide, ethoxyzolamide and chlorambucil, in the glyc-CDs was either increased or decreased compared to the other cyclodextrins. However, larger molecules, such as indomethacin and hydrocortisone, always bound better to the glyc-CDs with up to 180% increase in the stability constant. The degradation rate within the cyclodextrin cavity was not affected by the above derivation. 相似文献
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Data on the binding mode and thermodynamics of complex formation for various cyclodextrins (CDs) with flavines are summarized. It is shown that the governing factors of complexation are the size, degree of hydration, and hydrophobicity of the guest molecule. It is found that the presence of small hydrophobic substituents in a flavine’s structure increases their affinity toward cyclodextrin cavities, raising the stability of a complex. In contrast, the presence of bulky and polar side groups in a flavine’s structure prevents its inclusion in a macrocyclic cavity and weakens complexation. The size of a CD cavity plays a minor role in the interaction between CDs and flavines, since the inclusion of a guest molecule is only partial. 相似文献