- Synthesis of new water soluble β-cyclodextrin@curcumin conjugates and in vitro safety evaluation in primary cultures of rat cortical neurons
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Self-aggregation of Curcumin (Cur) in aqueous biological environment decreases its bioavailability and in vivo therapeutic efficacy, which hampers its clinical use as candidate for reducing risk of neurodegenerative diseases. Here, we focused on the design of new Cur-β-Cyclodextrin nanoconjugates to improve the solubility and reduce cell toxicity of Cur. In this study, we described the synthesis, structural characterization, photophysical properties and neuron cell toxicity of two new water soluble β-CD/Cur nanoconjugates as new strategy for reducing risks of neurodegenerative diseases. Cur was coupled to one or two β-CD molecules via triazole rings using CuAAC click chemistry strategy to yield β-CD@Cur and (β-CD)2 @Cur nanoconjugates, respectively. The synthesized nanoconjugates were found to be able to self-assemble in aqueous condition and form nano-aggregates of an average diameter size of around 35 and 120 nm for β-CD@Cur and (β-CD)2 @Cur, respectively. The photophysical properties, water solubility and cell toxicity on rat embryonic cortical neurons of the designed nanoconjugates were investigated and compared to that of Cur alone. The findings revealed that both new nanoconjugates displayed better water solubility and in vitro biocompatibility than Cur alone, thus making it possible to envisage their use as future nano-systems for the prevention or risk reduction of neurodegenerative diseases.
- Mihoub, Amina Ben,Acherar, Samir,Frochot, Céline,Malaplate, Catherine,Yen, Frances T.,Arab-Tehrany, Elmira
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- Optical-controlled antibacterial agent composed of linear-chain cation oligopeptides and multi-arm beta-cyclodextrin
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The invention discloses an optical-controlled antibacterial agent which is composed of linear-chain cation oligopeptides and multi-arm beta-cyclodextrin and utilizes illumination for regulating antibacterial activity, and belongs to the technical field of antibacterial materials. According to the optical-controlled antibacterial agent composed of the photo-responsive linear-chain cation oligopeptides and the multi-arm beta-cyclodextrin, the azobenzene-containing linear-chain cation oligopeptides and the multi-arm beta-cyclodextrin form a cross-linked aggregate through "subject-object" recognition. The linear-chain cation oligopeptides and the multi-arm beta-cyclodextrin have obviously different antibacterial activity in aggregation and disaggregation states. According to the optical-controlled antibacterial agent, a photo-isomerization characteristic of azobenzene conformations of the linear-chain cation oligopeptides is utilized for adjusting aggregation and disaggregation of "subject-object" recognition between azobenzene and the cyclodextrin to control formation and disintegration of the cross-linked aggregate, and thus the purpose of utilizing illumination for adjusting the antibacterial activity of the linear-chain cation oligopeptides is achieved; and that is to say, the optical-controlled antibacterial agent can change antibacterial activity under light irradiation, andthe antibacterial property of the optical-controlled antibacterial agent can be manually intervened in the aspects of time and space.
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Paragraph 0048-0050
(2020/03/05)
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- Improved Synthesis of C2 and C6 Monoderivatives of α- And β-Cyclodextrin via the Click Chemistry Approach
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An efficient multigram-scale azide-alkyne coupling of cyclodextrin derivatives mono-6-azido-6-deoxy-β-cyclodextrin, mono-2-O-propargyl-β-cyclodextrin, and mono-2-O-propargyl-α-cyclodextrin with terminal alkynyl aryl ethers or azides, mediated by copper(I) is reported. This process uses a stoichiometric ratio of substrates and 5 mol% of the copper catalyst to give the products with full conversion; thus, no chromatographic purification is necessary. The yields of both α- and β-cyclodextrin derivatives are in the range of 80 to 99%.
- Chmurski, Kazimierz,Stepniak, Pawel,Jurczak, Janusz
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p. 1838 - 1843
(2015/06/30)
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- Preparation of POSS-poly(ε-caprolactone)-β-cyclodextrin/Fe3O4hybrid magnetic micelles for removal of bisphenol A from water
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A novel amphiphilic star-shaped inorganic-organic hybrid copolymer polyhedral oligomeric silsesquioxane-poly(ε-caprolactone)-β-cyclodextrin (POSS-PCL-β-CD) was synthesized by ring-opening polymerization (ROP) and click chemistry. The amphiphilic copolymer can self-assemble into hybrid micelles with hydrophobic POSS-PCL chain encapsulating Fe3O4nanoparticles as the core and β-CD as the shell after mixing with Fe3O4nanoparticles in solvent and dialysis against water. The chemical structure of POSS-PCL-β-CD was characterized by 1H NMR and the morphology of the magnetic hybrid micelles was characterized by TEM and DLS. Due to the host-guest interaction of β-CD with bisphenol A (BPA), POSS-PCL-β-CD/Fe3O4hybrid micelles present good adsorption capacity in removal of BPA from aqueous solution. Magnetic measurement reveals that POSS-PCL-β-CD/Fe3O4hybrid micelles still exhibit magnetism for separation by an external magnetic field, indicating that these magnetic hybrid micelles may have potential application in the field of environmental protection.
- Yuan, Weizhong,Shen, Jin,Li, Lulin,Liu, Xu,Zou, Hui
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p. 353 - 361
(2015/02/19)
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- Nucleic acid complexes
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The invention relates to nucleic acid complexes, methods of preparation thereof, and uses thereof for delivering a nucleic acid into a cell.
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Page/Page column
(2015/01/07)
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- A mild one-step selective conversion of primary hydroxyl groups into azides in mono- and oligo-saccharides
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The direct azidation reaction of several monosaccharide methyl glycopyranosides, sucrose, α,α-trehalose, cyclomaltohexaose and cyclomaltoheptaose with sodium azide in the presence of triphenylphosphine-carbon tetrabromide is reported. The optimal reaction conditions require pre-formation of the reactive species before addition of the sugar substrate. Formation of the primary azidodeoxy compound is accompanied by simultaneous formation of the corresponding primary bromodeoxy and 3,6-anhydro derivatives in the glycopyranoside series, the former being transformed in situ into the azide by quenching of the reaction mixture with methanol before increasing the temperature. Interestingly, good selectivity towards the primary C-6 position of the glucopyranosyl moiety as compared to the fructofuranosyl one was observed in the case of sucrose, advantage of which has been taken in an improved preparation of 2,3,4,1',3',4',6'-hepta-O-acetyl-6-azido-6-deoxysucrose (45% yield from sucrose). Sodium or lithium azide reagents were found equally effective. The azide functionality could be reduced without previous purification and the resulting amino sugar isolated by cation-exchange column chromatography, as illustrated for the preparation of 6(I)-amino-6(I)-deoxycyclomaltoheptaose.
- Jimenez Blanco, Jose Luis,Garcia Fernandez, Jose Manuel,Gadelle, Andree,Defaye, Jacques
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p. 367 - 372
(2007/10/03)
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- The synthesis of functionalized cyclodextrins as scaffolds and templates for molecular diversity, catalysis, and inclusion phenomena
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α-, β-, and γ-cyclodextrins were chemically modified to selectively introduce functionality on the primary and secondary faces. Azido and substituted alkenyl groups were selectively introduced on the primary hydroxy groups to give monosubstituted derivatives. The secondary C-2 hydroxy group was selectively functionalized with allyl, 1-hexenyl, carboxymethyl, and ω-azidoalkyl groups (n: 3, 4, 5) as ethers. The chemically modified cyclodextrins are versatile molecules for use as scaffolds and templates in conjunction with chemical diversity, catalysis, and inclusion phenomena.
- Hanessian,Benalil,Laferriere
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p. 4786 - 4797
(2007/10/02)
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- Cooperative binding by aggregated mono-6-(alkylamino)-β-cyclodextrins
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Mono-6-(hexadecylamino)-β-cyclodextrin (5) and mono-6-(octylamino)-β-cyclodextrin (4) have been titrated against organic guests (4-nitrophenol, 4-hydroxybenzoic acid, cyclohexanecarboxylic acid, etc.) in aqueous solution to give sigmoidal binding isotherms. Replotting of these data according to the Hill equation gives Hill coefficients > 1.0 (2.2 in the case of 5 and 4-nitrophenol). In contrast, both β-cyclodextrin (β-CD) and mono-6-amino-β-cyclodextrin (3) both exhibit hyperbolic binding isotherms, leading to Hill coefficients close to unity. Hill coefficients greater than one are the experimental hallmark of cooperativity, in which initial binding events render subsequent binding events more favorable. The degree of cooperativity is sensitive to the concentration of the hosts (4 and 5) and the solvent (cooperativity is suppressed in DMSO). These results are discussed in terms of the aggregation properties of the amphipathic hosts (cmc = 200 and 1.4 μM, for 4 and 5, respectively), which were studied by conductivity, dynamic light scattering, and NMR. Two possible mechanisms to account for the observed cooperativity are presented and discussed.
- Petter, Russell C.,Salek, Jeffrey S.,Sikorski, Christopher T.,Kumaravel,Lin, Fu-Tyan
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p. 3860 - 3868
(2007/10/02)
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