Cyclodextrin-Einschlußverbindungen in Forschung und Industrie

Saenger, Wolfram

doi:10.1002/ange.19800920505

Cited by 272 publications

(76 citation statements)

References 244 publications

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“…Der Ladungstransport bei der Ausbildung der partiell oxidierten DTB-Stapel und der Polyiodid-Ketten erfolgt wohl nicht wie bei den a-Cyclodextrin/ Iod-Verbindungen über Iod/Wasserstoff-Brücken [18], sondern eher über Iod/Schwefel-Wechselwirkungen. Dies ergibt aus einem Vergleich der Abstän-de zwischen den Iodkanälen und den nächstliegen-den Wasserstoff-bzw.…”

Section: Darstellungsvorschriftunclassified

Selbststapelnde Systeme, I 4,4′,5,5′-Tetramethoxy-2,2′-dithiobiphenyl-Iod (6/7), eine Verbindung mit Radikalkationen und Polyiodidketten / Selfstacking Systems, I 4,4′5,5′-Tetramethoxy-2,2′-dithiobiphenyl-Iodine (6/7), a Compound with Radical Cations and Polyiodide Chains

Hinrichs

Kopf

Stender

et al. 1985

Zeitschrift Für Naturforschung B

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The title compound can be isolated from concentrated solutions of 4,4′,5,5′-tetramethoxy-2,2′- dithiobiphenyl (DTB, 2) and iodine as blue needles with brass-coloured luster. The crystal structure consists of stacks of (partially oxidized) DTB units with alternating orientations and of disordered polyiodide chains in channels between these stacks. The DTB molecule is not planar; the dihedral angle between the two phenyl rings is 25.1°, the dithio bridge is inclined by 41.7° to the longitudinal axis. The bond distances and angles of the disulfide group are in the normal range, the dihedral angles (CArSS′CAr′ = 55.6°, CArCArSS′ = 41.3°) differ from the ideal values of ca. 90° as a consequence of the cyclic structure

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Section: Darstellungsvorschriftunclassified

Selbststapelnde Systeme, I 4,4′,5,5′-Tetramethoxy-2,2′-dithiobiphenyl-Iod (6/7), eine Verbindung mit Radikalkationen und Polyiodidketten / Selfstacking Systems, I 4,4′5,5′-Tetramethoxy-2,2′-dithiobiphenyl-Iodine (6/7), a Compound with Radical Cations and Polyiodide Chains

Hinrichs

Kopf

Stender

et al. 1985

Zeitschrift Für Naturforschung B

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“…Secondly, selfquenching is still observed as a result of the self-aggregation of the fluorophore moieties. Thirdly, the dyads or triads are usually hydrophobic, which limits their applications in hydrophilic environments; in addition, they lack the necessary biocompatibility for applications in the fields of biotechnology.It is well known that cyclodextrin (CD) can form supramolecular inclusion complexes with small-molecule chromophore compounds that fit into its 5-8 cavity; [11][12][13] in this way, the fluorescence intensity, biocompatibility, and photostability of the guest chromophore compounds can be enhanced. [14,15] Herein, we synthesized photosensitive cyclodextrin (CDSP) by covalently attaching spiropyran moieties onto b-CD.…”

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confidence: 99%

Photoreversible Fluorescence Modulation of a Rhodamine Dye by Supramolecular Complexation with Photosensitive Cyclodextrin

Wu¹,

Luo²,

Zeng³

et al. 2007

Angew Chem Int Ed

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Materials with properties that can be optically modulated are of high interest in many scientific areas, including biotechnology and optics.[1] Photosensitive-in particular photochromic-compounds can be used to achieve this purpose, as they can be converted reversibly by light between two states with different spectroscopic properties. [2][3][4][5] This attribute can then be used to modulate or switch various functions at the molecular or supramolecular level by using light as a trigger. Spiropyran, a promising photochromic compound, undergoes reversible structural transformations in response to external inputs, such as light. [4,6,7] This special property of the spiropyran molecules was used to construct complex, optically controlled integrated logic gates and molecular switches composed of dyad or triad molecules with spiropyran as one of their units. [8][9][10] In this dyad or triad method, the modulation of various photonic or optoelectronic processes was usually realized by fluorescence quenching through energy transfer. In this approach to a light-controlled molecular switch or logic gate, several issues still need to be addressed: Firstly, the specific fluorophore must be covalently linked to the spiropyran molecule (or linked to it through a spacer) to form the dyad or the triad; hence, in this approach, only one dyad or triad can be used for a specific application. Secondly, selfquenching is still observed as a result of the self-aggregation of the fluorophore moieties. Thirdly, the dyads or triads are usually hydrophobic, which limits their applications in hydrophilic environments; in addition, they lack the necessary biocompatibility for applications in the fields of biotechnology.It is well known that cyclodextrin (CD) can form supramolecular inclusion complexes with small-molecule chromophore compounds that fit into its 5-8 cavity; [11][12][13] in this way, the fluorescence intensity, biocompatibility, and photostability of the guest chromophore compounds can be enhanced. [14,15] Herein, we synthesized photosensitive cyclodextrin (CDSP) by covalently attaching spiropyran moieties onto b-CD. Rhodamine B [16][17][18] (RhB) was used as a model fluorophore to form a supramolecular complex with the CDSP, and photoreversible fluorescence modulation was thus realized. This strategy is easily achievable, and the guest rhodamine molecules can be readily replaced by other chromophore compounds. In addition, the self-quenching of RhB can be decreased by supramolecular complexation. The strategy could provide a facile method for reversible fluorescence modulation, controlled by light, for a wide range of chromophores, which is essential in applications such as reversible bioimaging. At the same time, the chromophore complexes will have the necessary biocompatibility and hydrophilicity for applications in the field of biotechnology because of the presence of the oligosaccharide cyclodextrin.Photosensitive b-cyclodextrin was synthesized and based on mass spectrometry (MS), high-performance liquid chromatography (H...

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“…Cyclodextrins (CyDs) are cyclic oligosaccharides composed of 6 (a-CyD), 7 (b-CyD), and 8 (g-CyD) glucopyranose units and can form inclusion complexes with various organic and inorganic compounds. 4) Harada et al first reported the supramolecular assemblies of PEG and a-CyD, in which a number of the cyclic molecule are spontaneously threaded onto the polymer chain. 5,6) These complexes are called polypseudorotaxanes, because the CyD can be dethreaded from the polymer chain when dissolved in water.…”

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confidence: 99%

Polypseudorotaxane Formation of Randomly-Pegylated Insulin with Cyclodextrins: Slow Release and Resistance to Enzymatic Degradation

Higashi

Hirayama

Misumi

et al. 2009

CHEMICAL & PHARMACEUTICAL BULLETIN

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NotesPegylation technology is one of the useful methods for sustained release systems, because when poly(ethylene glycol) (PEG) is covalently attached to a protein, it transfers many of the polymer's favorable characteristics to the resulting conjugate, i.e. a number of benefits such as increased circulating half-life, enhanced proteolytic resistance, reduced antigenicity and immunogenicity, reduced aggregation, and improved bioavailability, etc. There are many examples of protein conjugates that are mono-or randomly-substituted with PEG, such as adenosine deamidase, insulin, interferona2, b-lactoglobulin, a-chymotrypsin, lipase, bovine liver catalase, asparaginase, and superoxide dismutase, etc. of which the first three conjugates are on the market.1-3) Most of commercially available pegylated drugs are randomly-substituted derivatives, because of synthetic difficulty of the mono-pegylation.Supramolecular assemblies have attracted a great amount of attention, due to its intriguing topologies and its application in various fields such as nanodevices, sensors, molecular switches, and drug delivery systems, etc. Cyclodextrins (CyDs) are cyclic oligosaccharides composed of 6 (a-CyD), 7 (b-CyD), and 8 (g-CyD) glucopyranose units and can form inclusion complexes with various organic and inorganic compounds.4) Harada et al. first reported the supramolecular assemblies of PEG and a-CyD, in which a number of the cyclic molecule are spontaneously threaded onto the polymer chain.5,6) These complexes are called polypseudorotaxanes, because the CyD can be dethreaded from the polymer chain when dissolved in water. Recently, many studies on CyD polypseudorotaxanes with various polymers were reported, e.g. blanched PEG, poly(ethylene imine) and poly(lactic acid), etc. [7][8][9] In addition, a number of applications of polypseudorotaxanes as a biomaterial were reported, e.g. gene delivery carrier, 10-13) biodegradable hydrogel 11,[14][15][16][17] and galectin binding material. 18) In previous studies, 19,20) we found that the mono-substituted pegylated insulin forms polypseudorotaxanes with a-and g-CyDs in a similar manner as PEG does. However, there are no evidences if randomly-or multiply-pegylated proteins form polypseudorotaxanes with CyDs. In this study, therefore, we prepared randomly-substituted pegylated insulin and its CyD polypseudorotaxanes and evaluated it as a sustained release system. Further, proteolytic behavior of insulin in the polypseudorotaxane was investigated. ExperimentalMaterials Bovine Zn-insulin (27.5 IU/mg, approximately 0.5% Zn) was obtained from Sigma Chemicals (St. Louis, MO, U.S.A.). a-Succinimidyloxysuccinyl-w-methoxy-polyoxyethylene (MW about 2300) was obtained from NOF Co. (Tokyo, Japan). CyDs were donated by Nihon Shokuhin Kako (Tokyo, Japan). All other materials were of reagent grade, and deionized double distilled water was used.Preparation of Randomly-Pegylated Insulin Randomly-pegylated insulin was synthesized according to the modified method of Hinds et al. 3,21) Briefly, insulin (MW 5734...

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Cyclodextrin-Einschlußverbindungen in Forschung und Industrie

Cited by 272 publications

References 244 publications

Selbststapelnde Systeme, I 4,4′,5,5′-Tetramethoxy-2,2′-dithiobiphenyl-Iod (6/7), eine Verbindung mit Radikalkationen und Polyiodidketten / Selfstacking Systems, I 4,4′5,5′-Tetramethoxy-2,2′-dithiobiphenyl-Iodine (6/7), a Compound with Radical Cations and Polyiodide Chains

Selbststapelnde Systeme, I 4,4′,5,5′-Tetramethoxy-2,2′-dithiobiphenyl-Iod (6/7), eine Verbindung mit Radikalkationen und Polyiodidketten / Selfstacking Systems, I 4,4′5,5′-Tetramethoxy-2,2′-dithiobiphenyl-Iodine (6/7), a Compound with Radical Cations and Polyiodide Chains

Photoreversible Fluorescence Modulation of a Rhodamine Dye by Supramolecular Complexation with Photosensitive Cyclodextrin

Polypseudorotaxane Formation of Randomly-Pegylated Insulin with Cyclodextrins: Slow Release and Resistance to Enzymatic Degradation

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