Cyclodextrin supramolecular systems

Wang XP, Pan JH, Yang XD, Niu CD, Zhang Y, Shuang SM. Porphyrin binding to DNA investigated by cyclodextrin supramolecular system. Anal Bioanal Chem 2002 374 445-50. 

The transition state of concerted Diels-Alder reactions has stringent regio- and stereochemical requirements and can assume settled configurations if the reaction is carried out in a molecular cavity. Cyclodextrins, porphyrin derivatives and cyclophanes are the supramolecular systems that have been most investigated. 

Supramolecular systems, 167, 168 cyclodextrins (CD), study of binding dynamics of guests to, 204-216 DNA, study of binding dynamics of guests to, 186-204... 

This paper is not a review covering the entire field of carbohydrate-recognition in any organized system. Many excellent papers have already been devoted to supramolecular systems such as cyclodextrins, podands, coronands or cryptants able to entrap carbohydrate molecules [1]. This article only deals with the molecular recognition of mono and oligosaccharides in organized self-assemblies of amphiphilic carbohydrates (possibly blended with other lipids) in aqueous medium i.e. in assemblies mimicking the cell membrane. 

In polar solvents amphiphilic molecules, that is molecules with a polar head and hydrophobic tail , tend to form various aggregates. The structure of micelles is usually much more complicated than that schematically shown in Figure 1.4 (see the pertaining discussion in Section 2.3). Nevertheless, in water they can include nonpolar molecules into their voids acting like surfactants applied in toiletry [15]. Similarly to cyclodextrins such as 11 [6, 16] and liquid crystals [7] discussed in Section 2.6, surfactants are examples of few supramolecular systems which have found numerous practical applications. 

Liu, Y. Li, L. and Chen, Y. (2002) Molecular Recognition Studies on Supramolecular Systems. Part 38. Inclusion Complexation of Organic Dyes by Organoselenium Bridged Bis-(/f-cyclodextrin)s with a Short linker,/. Incl. Phenom. 42, 151-155. 

Keywords Supramolecular system Block copolymer Self-assembled system Inclusion complexes Cyclodextrin Air-water interface Non-covalent interaction Auto-organization... 

In the supramolecular systems as the complexes of polymers and copolymers with cyclic molecules as cyclodextrins, the surface properties and the molecular motion must change when the polymer is free that when the polymer is included inside of a cyclic molecule. The polymer in the complexed form cannot have the same situation when it is in uncomplexed state. 

Asymmetric photoisomerization of cyclo-octene was also investigated in supramolecular systems such as native [153] and modified cyclodextrins [154,155], chirally-modified zeolite [156], and DNA grooves [157]. 

Lun W, Li Z, She S, et al. Direct fluorimetric determination of ascorbic acid by the supramolecular system of AA with P-cyclodextrin derivative. Acta A Mol Biomol Spectrosc 2005 11-12 2737-40. 

The modular NESI-chip system was used (i) to qualitatively as well as quantitatively study two well-known supramolecular systems, i.e. the Zn-porphyrin complexation with nitrogen-containing ligands in acetonitrile and the inclusion of small organic molecules into the cavity of (5-cyclodextrin in water,41 and (ii) to study the kinetics of the reaction of 4-nitro-7-piperazino-2,l,3-benzoxadiazole (NBDPZ) with isocyanates as a model system.42... 

This chapter covered the use of excited states as probes for dynamic studies involving supramolecular stmctures. It was shown that excited singlet and triplet states provide complementary capabilities for these studies. Micelles are the best characterized structures, and most of the methodology currently in use was developed when studying these supramolecular systems. Other self-assemblies, such as vesicles and bile salt aggregates, have been studied to some extent, but the dynamics of guest complexation has not been fully described and will undoubtedly be explored in the future. Cyclodextrins are widely employed as... 

Supramolecular chemistry typically involves the complexes based on molecular recognition, which include crown ethers, catenates, rotaxanes, etc. Azobenzene derivatives are often used as structural elements in such supramolecular assembly. Already in 1980 (Shinkai et ah, 1980), azobenzene moiety had been introduced into crown ether. Other recent examples include azobenzene-cyclodextrin complexes (Callari et ah, 2006), azobenzene-attached nanotube-cyclodextrin complexes (Descalzo et al., 2006), and molecular recognition complexes with DNA (Haruta et al., 2008). Numerous examples of photoswitch-able azobenzene supramolecular systems in solutions can be found (Yagai et al., 2005 Balzani et al., 2002). But there are no investigations in these systems concerning photoorientation and mass transport. 

Liu. Y. Han, B.H. Qi, A.D. Chen, R.T. Molecular recognition study of a supramolecular system. 11. Chiial recognition of aliphatic amino acids by natural and modified a-cyclodextrins in acidic aqueous solution. Bioorg. Chem. 1997. 25 (3), 155-162. 

It was demonstrated that the induced-fit concept of the interaction between an enzyme and a substrate was introduced from biological processes to supramolecular systems for explaining the molecular-binding behavior of artificial receptors, including crown ethers, cyclodextrins. calixarenes, porphyrins, etc. The induced-fit mechanism was utilized to explore the binding behavior of ions and molecules, and was adopted to accurately describe... 

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