Articles de revues : « Y-Cyclodextrin »

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ZHEKOVA, BORIANA Y., et VESELIN S. STANCHEV. « Reaction Conditions for Maximal Cyclodextrin Production by Cyclodextrin Glucanotransferase from Bacillus megaterium ». Polish Journal of Microbiology 60, n^o 2 (2011) : 113–18. http://dx.doi.org/10.33073/pjm-2011-015.

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The effect of the reaction conditions (substrate concentration, enzyme dosage, and pH) on cyclodextrin production by cyclodextrin glucanotransferase from Bacillus megaterium was investigated by applying mathematical modeling methods. Adequate models were developed and they were used for determination of the optimal conditions for maximal formation of beta-cyclodextrins at minimal concentrations of a- and gamma-cydclodextrins. The main factor affecting the ratio of the products was pH of the reaction mixture. At pH 9 the enzyme formed mainly beta- and y-cyclodextrins and the ratio a:beta:gamma was 2.6:83.5:13.9; at pH 5 the ratio changed to 8.6:84.6:6.8. Mathematical models were used for determination of the conditions for maximal conversion of the substrate into cyclodextrins. 45.88% conversion of starch was achieved at 5% substrate concentration, 3.5 U/g enzyme dosage, and pH 7.4.

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Viola, Luis, et Rita H. de Rossi. « Effect of cyclodextrin on elimination reactions ». Canadian Journal of Chemistry 77, n^o 5-6 (1 juin 1999) : 860–67. http://dx.doi.org/10.1139/v99-085.

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The reaction of 1-bromo-2-X-2-(Y-phenyl) ethane derivatives (1: X = Y = H; 2: X = Ph, Y = H; 3: X = H, Y = 4-Ac; 4: X = H, Y = 3-NO2; 5: X = H, Y = 4-NO2; 6: X = H, Y = 3-Me; 7: X = H, Y = 4-Me) in basic solution was studied, and in most cases, only the elimination product is formed. Only (2-bromo-1-phenylethyl)benzene, 2, yielded significant substitution product, and this yield decreased with the concentration of HO-. Addition of cyclodextrin (β-CD) diminished (about half for 0.02 M cyclodextrin concentration) the reaction rate of all substrates but 4 and 5. In the latter two cases, the rate rises. The observed rate-constant value at 0.5 M NaOH is 6.78 × 10-4 s-1 (at 40°C) and 1.80 × 10-3 s-1 (at 25°C) for 4 and 5, respectively. Under the same reaction conditions but with 0.01 M β-CD, the corresponding rates were 7.70 × 10-4 s-1 and 5.20 × 10-3 s-1. The elimination yield for 2 increased from 64 to 98% when the β-CD changed from zero to 0.02 M at 0.5 M NaHO. Also, there was an increase in the relative elimination products of 20-40% for compounds 6 and 7. The Hammet ρ values were 1.3 and 2.3 for the reaction in pure solvent and in the presence of β-cyclodextrin, indicating an increase in the negative character of the transition state for the reactions in the latter conditions. The results are interpreted in terms of the formation of an inclusion complex whose structure depends on the substrate.Key words: cyclodextrin, elimination reactions, inhibition, catalysis.

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Ngo, Huy T., Philip Clements, Christopher J. Easton, Duc-Truc Pham et Stephen F. Lincoln. « Supramolecular Chemistry of Pyronines B and Y, β-Cyclodextrin and Linked β-Cyclodextrin Dimers ». Australian Journal of Chemistry 63, n^o 4 (2010) : 687. http://dx.doi.org/10.1071/ch09467.

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The complexation of cationic pyronine B (PB+) and pyronine Y (PY+) by β-cyclodextrin (βCD) and two linked βCD dimers, N,N′-bis((2AS,3AS)-3A-deoxy-β-cyclodextrin-3A-yl)succinamide, 33βCD2suc, and N,N′-bis(6A-deoxy-β-cyclodextrin-6A-yl)succinamide, 66βCD2suc, in aqueous solution has been studied by UV-vis, fluorescence, and 1H NMR spectroscopy. The complexation constants for the 1:1 complexes: βCD.PB+, 33βCD2suc.PB+, 66βCD2suc.PB+, and the analogous PY+ complexes are reported as are the dimerization constants for PB+ and PY+. The modes of complexation, dimerization, and fluorescence quenching are discussed.

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Benkovics, Gábor, Damien Afonso, András Darcsi, Szabolcs Béni, Sabrina Conoci, Éva Fenyvesi, Lajos Szente, Milo Malanga et Salvatore Sortino. « Novel β-cyclodextrin–eosin conjugates ». Beilstein Journal of Organic Chemistry 13 (15 mars 2017) : 543–51. http://dx.doi.org/10.3762/bjoc.13.52.

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Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin–EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin–EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

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Duan, Zhengyang, Mingyao Song, Tianguo Li, Shuli Liu, Xiaojun Xu, Ronggao Qin, Changhua He, Yao Wang, Longqian Xu et Mengjiao Zhang. « Characterization and adsorption properties of cross-linked yeast/β-cyclodextrin polymers for Pb(ii) and Cd(ii) adsorption ». RSC Advances 8, n^o 55 (2018) : 31542–54. http://dx.doi.org/10.1039/c8ra06171h.

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IBRAKOVA, Nurgiza F., Galiya G. KUTLUGILDINA et Yuriy S. ZIMIN. « COMPLEXATION OF PRAZIQUANTEL WITH α-, β- AND y-CYCLODEXTRINS IN AQUEOUS-ALCOHOLIC SOLUTIONS ». Periódico Tchê Química 17, n^o 36 (20 décembre 2020) : 302–14. http://dx.doi.org/10.52571/ptq.v17.n36.2020.317_periodico36_pgs_302_314.pdf.

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Currently, the percentage of infections with invasive (parasitic) diseases is quite large; therefore, the treatment of helminthiases is an urgent problem in veterinary medicine. Parasitic worms inflict significant damage on animal husbandry, leading to the death of animals, shortage of meat, dairy products, and wool. The most common active ingredient in antihelmintics is praziquantel, which is well known as an effective broad-spectrum anthelmintic. At the same time, praziquantel has low solubility in water and a pronounced bitter taste, which represents a significant obstacle in developing liquid forms of drugs that are convenient for administration to animals. One way to solve these problems is the complexation of medicinal substances with various (natural and synthetic) compounds. In this regard, this paper aims to study the complexation of praziquantel with α-, β-, and -cyclodextrins in aqueous-alcoholic solutions. The studies were carried out by the method of ultraviolet spectroscopy. It was found that the addition of cyclodextrins to aqueous-alcoholic solutions of praziquantel leads to spectral changes indicating the presence of intermolecular interactions and complexation. The isomolar series method showed that in dilute solutions, praziquantel forms complex compounds with cyclodextrins 1:1, that is, one molecule of praziquantel falls on one molecule of α-, β- or y-cyclodextrin. The stability constants of the resulting complexes were calculated using the molar ratio method. It is shown that in the range of 296-316 K, the composition of complex compounds remains unchanged (1:1), and their stability decreases with increasing temperature. The study of the temperature dependences of the stability constants made it possible to determine the standard values of changes in the Gibbs energy, enthalpy, and complexation entropy.

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Wang, Yan, Yuyang Liu, Jianghu Liang et Minhao Zou. « A cyclodextrin-core star copolymer with Y-shaped ABC miktoarms and its unimolecular micelles ». RSC Advances 7, n^o 19 (2017) : 11691–700. http://dx.doi.org/10.1039/c6ra28456f.

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A β-cyclodextrin-core star copolymer with Y-shaped ABC miktoarms was designed which exhibits unimolecular micelles in aqueous solution. It is a good platform for unimolecular container encapsulating hydrophobic molecules with release of the payload exhibiting pH-sensitivity.

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Yao, Hao, Wei Tian, Yuezhou Liu, Yang Bai, Dizheng Liu, Tingting Liu, Miao Qi, Min Wang et Yuyang Liu. « Cyclodextrin-tunable reversible self-assembly of a thermoresponsive Y-shaped polymer ». RSC Advances 5, n^o 44 (2015) : 34557–65. http://dx.doi.org/10.1039/c5ra03064a.

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Chekroud, Hassina, Fayçal Djazi, Bouhadiba Abd alaziz, Karima Horchani-Naifer, Zeghdoudi Rachida et Remache Malika. « Modeling and Optimisation of Comlexity by the β-Cyclodextrin of an Organic Pollutant Model : m-Methyl Red ». Chemistry & ; Chemical Technology 16, n^o 2 (15 juin 2022) : 195–202. http://dx.doi.org/10.23939/chcht16.02.195.

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Studies of cyclodextrin chemistry using quantum chemical methods are mainly adopted to investigate the formation of the inclusion complex causing changes in the physicochemical properties of the cyclodextrin guest. In this paper, we conducted a computational modeling study of the inclusion complexes of β-cyclodextrin (β-CD) with m-Methyl Red (m-MR) by using parametric method 6 (PM6), the semi empirical molecular orbital calculations and the natural bond orbital method (NBO). The inclusion process is carried out by maintaining the coordinates of the β-CD fixed and by displacing the guest molecule. The different relative positions between m-MR and β-CD are measured with respect to the distance between the reference atom (N) in the guest molecule and the origin of the coordinates from the equatorial plane of β-CD. The m-MR/β-CD (B) inclusion complex has a lower negative value of ΔG compared to another m-MR/β-CD (A) complex, highlighting the spontaneous behavior of the inclusion process. In addition, during the process of inclusion, the complexation energy is negative, which allows us to affirm that the complexation of m-MR in the β-CD is thermodynamically favorable. Among two directions A and B, the minimum energy generated from the PM6 was obtained in the orientation B and the guest molecule is partially encapsulated in the cavity of β-CD. In the NBO analysis, the stabilization energy is also usually used to characterize the hydrogen bond interaction between a lone pair (LP(Y)) of an atom Y and an anti-bonding orbital (BD٭(X-H)).

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Delrivo, Alicia, Gladys Granero et Marcela Longhi. « Studies of ternary systems of sulfadiazine with β-cyclodextrin and aminoacids ». Ars Pharmaceutica (Internet) 57, n^o 4 (20 décembre 2016) : 167–76. http://dx.doi.org/10.30827/ars.v57i4.5561.

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Introduction: Cyclodextrins (CD), are known to form inclusion complexes with a variety of guest molecules both in solution and in the solid state. This can lead to the alteration of properties of guest molecules. Unfortunately, the complexation efficiency of CD is rather low, and can be enhanced by formation of ternary complexes using aminoacids (AA). Sulfadiazine (SDZ) is an antibiotic with extremely low water solubility which limits its therapeutic applications and bioavailability. Objetives: The aim of this work was to increase the aqueous solubility of SDZ by preparing ternary complexes of this drug with β-cyclodextrin (βCD) and an AA as a third auxiliary substance. Materials y Methods: Complex formation was studied by phase solubility analysis (PSA), nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and scanning electron microscopy (SEM). Results: The apparent stability constants (KC) of the multicomponent complexes were calculated from the solubility diagrams. By the analysis of the NMR spectra, it could be said that the shifts of some protons evidenced the important role of the AA in the formation of multicomponent complexes. Among the AA, Arginine (ARG) proved to have better solubilizing properties for SDZ, reaching an improvement up to 70 times. The use of DSC, TG and SEM suggested the formation of new solid phases between SDZ:βCD:AA. Conclusions: As a result of this research, it was determined that ternary products were more effective in improving drug solubility than the corresponding SDZ:βCD binary system.

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Ferrarelli, Leslie K. « Papers of note in Science Translational Medicine ». Science Signaling 9, n^o 423 (12 avril 2016) : ec88-ec88. http://dx.doi.org/10.1126/scisignal.aaf8382.

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CANCERA winning combinationAndrogen receptor antagonists compromise the T cell response against prostate cancer, leading to early tumor relapse.Y. Pu, M. Xu, Y. Liang, K. Yang, Y. Guo, X. Yang, Y.-X. Fu, Androgen receptor antagonists compromise T cell response against prostate cancer leading to early tumor relapse. Sci. Transl. Med.8, 333ra47 (2016). [Abstract]NEUROTOXICITYInsights into neuronal cell deathA method to culture human cortical neurons that yielded a balanced network of excitatory and inhibitory neurons revealed that these cells die in a PARP-dependent manner after neurotoxic insult.J.-C. Xu, J. Fan, X. Wang, S. M. Eacker, T.-I. Kam, L. Chen, X. Yin, J. Zhu, Z. Chi, H. Jiang, R. Chen, T. M. Dawson, V. L. Dawson, Cultured networks of excitatory projection neurons and inhibitory interneurons for studying human cortical neurotoxicity. Sci. Transl. Med.8, 333ra48 (2016). [Abstract]ATHEROSCLEROSISDissolving away cholesterolThe cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin facilitates atheroprotective mechanisms through oxysterol-mediated reprogramming of macrophages.S. Zimmer, A. Grebe, S. S. Bakke, N. Bode, B. Halvorsen, T. Ulas, M. Skjelland, D. De Nardo, L. I. Labzin, A. Kerksiek, C. Hempel, M. T. Heneka, V. Hawxhurst, M. L. Fitzgerald, J. Trebicka, I. Björkhem, J.-Å. Gustafsson, M. Westerterp, A. R. Tall, S. D. Wright, T. Espevik, J. L. Schultze, G. Nickenig, D. Lütjohann, E. Latz, Cyclodextrin promotes atherosclerosis regression via macrophage reprogramming. Sci. Transl. Med. 8, 333ra50 (2016). [Abstract]

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Shirao, Satoshi, Hiroshi Yoneda, Mizuya Shinoyama, Kazutaka Sugimoto, Hiroyasu Koizumi, Hideyuki Ishihara, Fumiaki Oka et al. « A Novel Trigger for Cholesterol-Dependent Smooth Muscle Contraction Mediated by the Sphingosylphosphorylcholine-Rho-Kinase Pathway in the Rat Basilar Artery : A Mechanistic Role for Lipid Rafts ». Journal of Cerebral Blood Flow & ; Metabolism 35, n^o 5 (21 janvier 2015) : 835–42. http://dx.doi.org/10.1038/jcbfm.2014.260.

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Hyperlipidemia is a risk factor for abnormal cerebrovascular events. Rafts are cholesterol-enriched membrane microdomains that influence signal transduction. We previously showed that Rho-kinase-mediated Ca2+ sensitization of vascular smooth muscle (VSM) induced by sphingosylphosphorylcholine (SPC) has a pivotal role in cerebral vasospasm. The goals of the study were to show SPC-Rho-kinase-mediated VSM contraction in vivo and to link this effect to cholesterol and rafts. The SPC-induced VSM contraction measured using a cranial window model was reversed by Y-27632, a Rho-kinase inhibitor, in rats fed a control diet. The extent of SPC-induced contraction correlated with serum total cholesterol. Total cholesterol levels in the internal carotid artery (ICA) were significantly higher in rats fed a cholesterol diet compared with a control diet or a β-cyclodextrin diet, which depletes VSM cholesterol. Western blotting and real-time PCR revealed increases in flotillin-1, a raft marker, and flotillin-1 mRNA in the ICA in rats fed a cholesterol diet, but not in rats fed the β-cyclodextrin diet. Depletion of cholesterol decreased rafts in VSM cells, and prevention of an increase in cholesterol by β-cyclodextrin inhibited SPC-induced contraction in a cranial window model. These results indicate that cholesterol potentiates SPC-Rho-kinase-mediated contractions of importance in cerebral vasospasm and are compatible with a role for rafts in this process.

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Jansook, Phatsawee, Garnpimol C. Ritthidej, Haruhisa Ueda, Einar Stefánsson et Thorsteinn Loftsson. « yCD/HPyCD Mixtures as Solubilizer : Solid-State Characterization and Sample Dexamethasone Eye Drop Suspension ». Journal of Pharmacy & ; Pharmaceutical Sciences 13, n^o 3 (6 septembre 2010) : 336. http://dx.doi.org/10.18433/j3m88b.

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Purpose. Study the complexation of dexamethasone in combinations of y-cyclodextrin (yCD) and 2-hydroxypropyl-y-cyclodextrin (HPyCD) with emphasis on solid characterization and development of aqueous dexamethasone eye drop suspension for drug delivery through sclera. Methods. Dexamethasone/cyclodextrin (dexamethasone/CD) solid complex systems were prepared and characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), X-ray diffractometry (XRD), and by in vitro drug dissolution testing. Sample eye drop suspensions were prepared applying solubilizer/suspender consisting of yCD/HPyCD mixtures, poloxamer 407 (P407) and polyvinylpyrrolidone. The eye drop suspension was characterized by its physicochemical properties. Results. The solid characterization techniques applied suggested that solid complexes were being formed. The results indicated that dexamethasone formed non-inclusion or micelle-like aggregates with HPyCD and the yCD/HPyCD mixture. The dissolution and dexamethasone release from the solid dexamethasone/yCD/HPyCD complexes was much faster than from the solid dexamethasone/yCD and dexamethasone/HPyCD complexes. The diameter of the solid particles in the dexamethasone eye drop suspension formulations were in all cases less than 10 μm with a mean diameter from 2.5 to 5.8 μm. The particle size decreased with increasing amount of P407. Permeation studies through semi-permeable membrane and porcine sclera showed that increasing the amount HPyCD could enhance drug transport through the membrane barriers and this was related to enhanced drug solubility. The permeation rates were, however, decreased compared to formulation containing yCD alone due to larger hydrodynamic diameter of dexamethasone/yCD/HPyCD complex aggregates. All formulations were both chemically stable for at least 8 months at 25oC and 40oC. Conclusions. Combination of yCD and HPyCD, i.e., formation of dexamethasone/yCD/HPyCD complexes, resulted in synergistic effect. That is the mixture had greater solubilizing effect than the individual CD, resulted in enhanced dissolution and drug delivery through membranes. Furthermore, it is possible to control the drug release rate by adjusting the yCD:HPyCD ratio in the solid dexamethasone/yCD/HPyCD complexes.

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Reija, Belén, Wajih Al-Soufi, Mercedes Novo et José Vázquez Tato. « Specific Interactions in the Inclusion Complexes of Pyronines Y and B with β-Cyclodextrin ». Journal of Physical Chemistry B 109, n^o 4 (février 2005) : 1364–70. http://dx.doi.org/10.1021/jp046587b.

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Schiller, Robert L., Stephen F. Lincoln et John H. Coates. « The inclusion of pyronine Y by β- and γ-cyclodextrin. A Kinetic and equilibrium study ». Journal of the Chemical Society, Faraday Transactions 1 : Physical Chemistry in Condensed Phases 83, n^o 11 (1987) : 3237. http://dx.doi.org/10.1039/f19878303237.

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Hamada, Hiroki, Kohji Ishihara, Kei Shimoda, Atsuhito Kuboki, Yuya Kiriake et Ryusuke Hosoda. « Enzymatic Synthesis of Memantine (Memary) Oligosaccharides (Gluco-oligosaccharides) and their application as anti-dementia drugs that cross the Blood-Brain Barrier (BBB) ». International Journal of Current Microbiology and Applied Sciences 12, n^o 8 (10 août 2023) : 1–6. http://dx.doi.org/10.20546/ijcmas.2023.1208.001.

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Memantine (memary) oligosaccharides (gluco-oligosaccharides) were synthesized by enzymatic glycosylation, using cyclodextrin glucanotransferase as a biocatalyst. Although memantine hardly crosses the blood–brain barrier (BBB) in the mouse brain, memantine oligosaccharides crossed the BBB of mouse brain and were incorporated into the mouse brain tissue. Our investigations indicated that memantine modified with oligosaccharides might have gained a BBB-crossing ability. Furthermore, during the Y-maze test using senescence-accelerated mouse prone 8, our study revealed that the time spent in the novel Y-maze arm by the memantine-oligosaccharides-treated mouse was longer than that spent in the novel arm by the memantine-treated-mouse. Therefore, this study established that since memantine oligosaccharides could penetrate the BBB of mouse brain and be incorporated into the mouse’s brain tissue, they could also enhance spatial learning.

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Hamada, Hiroki, Kohji Ishihara, Kei Shimoda, Atsuhito Kuboki, Yuya Kiriake, Ryusuke Hosoda et Noriyuki Uchida. « Enzymatic Synthesis of Resveratrol Oligosaccharides (Gluco-oligosaccharides) and their Enhanced Application as Antidementia Drugs that Cross the Blood-brain Barrier (BBB) ». International Journal of Current Microbiology and Applied Sciences 11, n^o 7 (10 juillet 2022) : 260–66. http://dx.doi.org/10.20546/ijcmas.2022.1107.031.

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This study synthesized resveratrol oligosaccharides (gluco oligosaccharides) by two-step enzymatic glycosylation, using glucosyltransferase from Phytolacca americana and cyclodextrin glucanotransferase. Although resveratrol hardly crosses the blood–brain barrier (BBB) in the mouse brain, the synthesized resveratrol oligosaccharides incorporated into the mouse brain tissue crossed the BBB. Our study indicated that resveratrol modified with oligosaccharides might have gained a BBB-crossing ability. Furthermore, during the Y-maze test using senescence-accelerated mouse prone 8, our investigations revealed that the time spent in the novel Y-maze arm by the resveratrol-oligosaccharides-treated mice was longer than that spent in the novel arm by the resveratrol-treated-mice. Therefore, this study established that since resveratrol oligosaccharides could penetrate the BBB of mouse brain samples and be incorporated into the mouse’s brain tissue, they could also enhance spatial learning.

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Barbosa, Jéssica S., Karyna Lysenko, Filipe A. Almeida Paz et Susana Santos Braga. « Inclusion of Montelukast in y-Cyclodextrin : Presenting a Mechanochemical Route to Improve Drug Stability and Solubility ». Proceedings 78, n^o 1 (1 décembre 2020) : 18. http://dx.doi.org/10.3390/iecp2020-08717.

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Montelukast sodium (MLK) is a worldwide antiasthmatic drug. Commercial formulations still have some issues with solubility and instability to light and humidity. To overcome them, the present work reports inclusion compounds of MLK and γ-cyclodextrin (γ-CD). As a molecular capsule, CDs have the ability to protect the inclusion guest from degradation, enhance its solubility and alter the pharmacokinetic parameters. MLKγ-CD inclusion compounds were prepared by mechanochemistry. Without using any solvent, γ-CD was pre-milled and then co-milled with an equimolar quantity of MLK in a ball mill at 600 cycles·min−1. After 120 min of milling, the formation of MLK·γ-CD inclusion compounds was confirmed by powder X-ray diffraction and scanning electron microscopy. Additional studies, performed under pharmacopeia guidelines, showed that the prepared MLKγ-CD inclusion compounds can indeed increase the dissolution of MLK when in ultrapure water or simulated intestinal fluid (without pancreatin). This way, the MLKγ-CD inclusion compounds that are presented in this work are a promising solution for improving the therapeutic effectiveness of MLK.

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Paramanick, Debashish, Kagithala Naga Rani, Vijay Kumar Singh, Parakh Basist, Rahmuddin Khan, Jameel H. Al-Tamimi, Omar M. Noman, Mansour N. Ibrahim et Abdulsalam Alhalmi. « Enhancement of Cognitive Function by Andrographolide-Loaded Lactose β-Cyclodextrin Nanoparticles : Synthesis, Optimization, and Behavioural Assessment ». Pharmaceuticals 17, n^o 7 (21 juillet 2024) : 966. http://dx.doi.org/10.3390/ph17070966.

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This study investigates whether Andrographolide-loaded Lactose β-Cyclodextrin (ALN-βCD) nanoparticles enhance cognitive function, particularly spatial learning and memory. The successful conjugation of lactose to β-cyclodextrin was confirmed via 1H NMR spectroscopy, facilitating neuronal cell entry. The solvent evaporation method was used to create the nanoparticles, which were characterised for particle size, PDI, zeta potential, and drug release. The nanoparticles exhibited a size of 247.9 ± 3.2 nm, a PDI of 0.5 ± 0.02, and a zeta potential of 26.8 ± 2.5 mV. FTIR and TEM analyses, along with in vitro drug release and BBB permeability studies, confirmed their stability and efficacy. Behavioural tests, including the Elevated Plus Maze, Y-Maze, Object Recognition, and Locomotor Activity tests, demonstrated significant improvements in memory, motor coordination, and exploration time in the nanoparticle-treated groups. The group treated with ALN-βCD at a dose of 100 mg/kg/p.o. showed superior cognitive performance compared to the group receiving free andrographolides (AG). Biochemical assays indicated a significant reduction in acetylcholinesterase activity and lipid peroxidation, suggesting increased acetylcholine levels and reduced oxidative stress. Histopathological examination showed improved neuronal function without toxicity. The results showed significant improvements (p < 0.001) in memory and cognitive abilities in experimental animals, highlighting the potential of ALN-βCD nanoparticles as a non-invasive treatment for memory loss. These promising findings warrant further exploration through clinical trials.

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Desai, Drashti, et Pravin Shende. « Monodispersed cyclodextrin-based nanocomplex of neuropeptide Y for targeting MCF-7 cells using a central composite design ». Journal of Drug Delivery Science and Technology 65 (octobre 2021) : 102692. http://dx.doi.org/10.1016/j.jddst.2021.102692.

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Bordello, Jorge, Belén Reija, Wajih Al-Soufi et Mercedes Novo. « Host-Assisted Guest Self-Assembly : Enhancement of the Dimerization of Pyronines Y and B by γ-Cyclodextrin ». ChemPhysChem 10, n^o 6 (14 avril 2009) : 931–39. http://dx.doi.org/10.1002/cphc.200800776.

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Peixoto, Carine Mascena, Sheila Lorena de Araújo Coelho et Marcia Luciana Cazetta. « Byproducts from cassava industry : alternative substrates for cyclodextrin glycosyltransferase production by alkalophilic Bacillus trypoxylicola SM–02 ». Anales de Biología, n^o 42 (31 mars 2020) : 37–46. http://dx.doi.org/10.6018/analesbio.42.05.

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Bioproductos de la industria de la yuca: sustratos alternativos para la producción de ciclodextrina glucosiltransferasa por alcalófilo Bacillus trypoxylicola SM-02 En el presente trabajo estudiamos el uso licor de maíz fermentado (LMF), harina de cáscara de yuca (HCY) y aguas residuales de yuca para la producción de ciclodextina glicosiltransferasa (CGTase) por un nuevo aislado alcalófilo de Bacillus trypoxylicola SM-02 en fermentación sumergida. Los experimentos se realizaron por Diseño Central Compuesto Rotativo 22 totalizando 11 ensayos. La mayor actividad enzimática de 352.53 U/mL se obtuvo con 1.5 g de HCY y 0.6 g de LMF. La temperatura y el pH óptimos fueron 55 ºC y pH 8.0, respectivamente. CGTase mostró una actividad relativa superior al 50% durante 120 min. a la temperatura óptima. Solo el CaCl2 mostró actividad positiva para CGTasa. Los resultados apuntaron a un buen potencial de B. trypoxylicola SM-02 para la producción de CGTasa usando substratos residuales. In the present work was studied the use of cassava peel flour (CPF), corn steep liquor (CSL), and cassava wastewater as substrates to produce cyclodextrin glycosyltransferase (CGTase) from a new alkalophilic isolate of Bacillus trypoxylicola SM-02 by submerged fermentation. The experiments were performed as a Central Composite Design 22, totalizing 11 assays. An enzymatic activity of 352.53 U/mL was obtained using 1.5 g of CPF and 0.6 g of CSL. The optimum temperature and pH of CGTase was 55 °C and 8.0, respectively. The CGTase depicted a relative activity of more than 50% for 120 min at the optimum temperature. The only salt that positively influenced the CGTase activity was CaCl2. The results are indicative of a potential role of B. trypoxylicola SM-02 in the production of CGTase using residual substrates.

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Song, Yun, Yong Chen et Yu Liu. « Switchable fluorescence behaviors of pyronine Y at different pH values upon complexation with biquinolino-bridged bis(β-cyclodextrin) ». Journal of Photochemistry and Photobiology A : Chemistry 173, n^o 3 (juillet 2005) : 328–33. http://dx.doi.org/10.1016/j.jphotochem.2005.04.012.

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Huang, Yi-Chang, Jau-Tsuen Kao et Keh-Sung Tsai. « Evaluation of two homogeneous methods for measuring high-density lipoprotein cholesterol ». Clinical Chemistry 43, n^o 6 (1 juin 1997) : 1048–55. http://dx.doi.org/10.1093/clinchem/43.6.1048.

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Abstract We evaluated the performance of two homogeneous assays for quantifying HDL cholesterol (HDL-C) and compared them with the phosphotungstic acid (PTA)/MgCl2 assay. Both homogeneous HDL-C assays were precise, having a within-run CV of <1.20% and a between-run CV of <4.07%. The HDL-C values (y) measured by the two homogeneous methods correlated well with those by the PTA/MgCl2 method (x): y = 1.00x + 64.98 mg/L, r = 0.987, Sy|x = 27.99 mg/L (n = 152) for the polyethylene glycol-modified enzymes/α-cyclodextrin sulfate (PEGME) assay (Kyowa), and y = 0.84x + 106.51 mg/L, r = 0.984, Sy|x = 26.10 mg/L (n = 152) for the polyanion–polymer/detergent (PPD) assay (Daiichi). The specificity of the PEGME method seemed better than that of the PPD method, as the PPD method was markedly interfered with by supplemental LDL-C. Addition of 20 g/L triglycerides produced a negative error of ∼18% in both homogeneous assays. Bilirubin and hemoglobin had little influence on the PEGME method; hemoglobin had little effect on the PPD method. Bilirubin, however, markedly decreased the readings by the PPD method. We found the PEGME assay superior to the PPD assay for routine HDL-C testing, because the PPD assay is relatively inaccurate and not specific.

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Kudryashov, S. Yu, K. A. Kopytin, M. Yu Pavlov, L. A. Onuchak et Yu G. Kuraeva. « Adsorption of organic vapors on the Carbopack Y carbon adsorbent modified with heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin ». Russian Journal of Physical Chemistry A 84, n^o 3 (janvier 2010) : 495–502. http://dx.doi.org/10.1134/s003602441003026x.

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Al Azzam, Khaldun M. « Binding Constants Determination of Ofloxacin and Ornidazole Enantiomers with Sulfated β-Cyclodextrin as Single Ligand by Capillary Electrophoresis using Three Different Linear Plotting Methods ». Asian Journal of Chemistry 33, n^o 7 (2021) : 1663–70. http://dx.doi.org/10.14233/ajchem.2021.23286.

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The aim of this research is to use capillary electrophoresis to establish/determine the binding constants for ofloxacin and ornidazole enantiomers with the negatively charged chiral selector sulfated-β-cyclodextrin (S-β-CD). Using electrophoretic mobility values of ofloxacin and ornidazole enantiomers at various concentrations of S-β-CD used in the context of background electrolyte (BGE), binding constants were calculated using three separate linearization plots, namely double-reciprocal, X-reciprocal and Y-reciprocal. The R-ofloxacin enantiomer-S-β-CD complex had the highest inclusion affinity of the ofloxacin and ornidazole enantiomers, which matched with previously reported estimation. Every enantiomer-S-β-CD complex’s binding constants, as well as thermodynamic binding parameters, were calculated at different temperatures. The host-guest binding constants using double reciprocal fit showed greater linearity (R2 > 0.99) at all temperature ranges measured (15-30 ºC) as compared to the other two fit approaches. The thermodynamic complexation parameters were found to be dependent on the temperature of the enantiomers, as seen by the linear van’t Hoff (15-30 ºC) plot.

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Simões-Silva, M. R., A. S. G. Nefertiti, J. S. De Araújo, M. M. Batista, P. B. Da Silva, M. T. Bahia, R. S. Menna-Barreto et al. « Phenotypic ScreeningIn Vitroof Novel Aromatic Amidines against Trypanosoma cruzi ». Antimicrobial Agents and Chemotherapy 60, n^o 8 (23 mai 2016) : 4701–7. http://dx.doi.org/10.1128/aac.01788-15.

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ABSTRACTThe current treatment of Chagas disease (CD), based on nifurtimox and benznidazole (Bz), is unsatisfactory. In this context, we performed the phenotypicin vitroscreening of novel mono- and diamidines and drug interaction assays with selected compounds. Ten novel amidines were tested for their activities against bloodstream trypomastigote (BT) and amastigote forms ofTrypanosoma cruzi(Y and Tulahuen strains) and their toxicities for mammalian host cells (L929 cells and cardiac cells). Seven of 10 molecules were more active than Bz against BT, with the most active compound being the diamidine DB2267 (50% effective concentration [EC50] = 0.23 μM; selectivity index = 417), which was 28-fold more active and about 3 times more selective than the standard drug. Five of the six monoamidines were also more active than Bz. The combination of DB2267 and DB2236 in fixed-ratio proportions showed an additive effect (sum of fractional inhibitory concentrations < 4) on BT. Interestingly, when intracellular forms were exposed to DB2267, its activity was dependent on the parasite strain, being effective (EC50= 0.87 ± 0.05 μM) against a discrete typing unit (DTU) II strain (strain Y) but not against a representative DTU VI strain (strain Tulahuen) even when different vehicles (β-cyclodextrin and dimethyl sulfoxide) were used. The intrinsic fluorescence of several diamidines allowed their uptake to be studied. Testing of the uptake of DB2236 (inactive) and DB2267 (active) by amastigotes of the Y strain showed that the two compounds were localized intracellularly in different compartments: DB2236 in the cytoplasm and DB2267 in the nucleus. Our present data encourage further studies regarding the activities of amidines and provide information which will help with the identification of novel agents for the treatment of CD.

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Yuca, Neslihan, Emre Guney, Omer Suat Taskin, Ilknur Kalafat et Büşra Çetin. « (Invited) Autonomous Self-Healable Silicon Anode for Next Generation Lithium-Ion Batteries ». ECS Meeting Abstracts MA2023-02, n^o 6 (22 décembre 2023) : 898. http://dx.doi.org/10.1149/ma2023-026898mtgabs.

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Self-healing is a measure of material's ability to repair damage. Physical and chemical processes have been used to obtain self-healing polymers for various applications. Different approaches are involved for these systems, such as shape-memory effects, covalent-bond reform, heterogeneous systems, diffusion and flow, and the dynamics of supramolecular chemistry. Different approaches are used to achieve self-healing polymers, in particular, the role of the healing system in chemistry is highlighted, which enables thermal transients, damage repairing and reconnection. Moreover, self-healing systems and their energy storage applications are currently getting great importance. Inspired by the dynamic network structure of animal dermis, in which collagen fibril (rigid and strong) and elastin fibril (soft and elastic) crosslink through supramolecular interactions to form a sturdy and flexible material we hypothesized that the combination of a rigid conductive polymer with a soft hydrophilic polymer through proper supramolecular interactions would yield a strong and robust polymer binder. According to the literature, the external stimulus such as heat, light, pH and redox initiate the healing process. This process is known as non-autonomous self-healing when some additional external stimulus is needed. Considering the battery chemistry, it is the most functional method to choose self-healing structures and batteries with the help of hydrogen bonds in order to make the self-healing process occurs autonomously. In the literature, polymerized β-cyclodextrin (β-CD) has been used as an advanced binder for Si-nanoparticle anodes, and cracks in the electrode can be avoided with its reversible properties through supramolecular cyclodextrin or hydrogen bonding compounds[1]. Dynamic bonds such as hydrogen bonds between composites positively affect the durability of the Si anode performance. For example, the Si anode was coated by the researchers with hydrogen bond-oriented polymer binder layers based on polyimide polymer such as Upy, resulting in electrochemical performance ten times longer than conventional silicon anodes[2]. Horizon projects such as BAT4EVER and HIDDEN under Battery 2030+ initiative have been investigate the integration and optimization of self-healing polymers in Li-ion battery [3]. In the scope of the BAT4EVER project, supramolecular coupling of polyaniline and polyvinyl alcohol via dynamic boronate bond yields polyaniline-polyvinyl alcohol hydrogel with outstanding tensile strength and electrochemical performance. The self-healing chemistry in the Si anode prevents unbalanced volumetric changes and cracks on the electrode surface. Thus, electrochemical performance losses are decreased. The self-healing functionalized components of lithium-ion batteries, which focus on improving and optimizing properties such as high energy density, high voltage, long life, and cycle stability, are of great importance for next-generation batteries. References Jeong, Y.K., Kwon, T.W., Lee, I., Kim, T.S., Coskun, A., Choi, J.W.: Hyperbranched β-cyclodextrin polymer as an effective multidimensional binder for silicon anodes in lithium rechargeable batteries. Nano Lett. 14, 864–870 (2014). https://doi.org/10.1021/NL404237J/SUPPL_FILE/NL404237J_SI_001.PDF Yang, J., Zhang, L., Zhang, T., Wang, X., Gao, Y., Fang, Q.: Self-healing strategy for Si nanoparticles towards practical application as anode materials for Li-ion batteries. Electrochem commun. 87, 22–26 (2018). https://doi.org/10.1016/J.ELECOM.2017.12.023 https://battery2030.eu/ This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement 957225 (BAT4EVER).

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Ansa-Addo, Ephraim A., Igor dos Santos Cestari, Paras Pathak, Marcel I. Ramirez et Jameel M. Inal. « Monocytic THP-1 cells stimulated by normal human serum (NHS) release cytokine-bearing plasma membrane-derived vesicles (PMVs), and can be inhibited by methyl-beta-cyclodextrin, calpeptin and Rho-kinase inhibitor, Y-27632 (98.27) ». Journal of Immunology 182, n^o 1_Supplement (1 avril 2009) : 98.27. http://dx.doi.org/10.4049/jimmunol.182.supp.98.27.

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Abstract Stimulation of human acute monocytic cells with sublytic complement leads to an increase of intracellular calcium resulting in the release of two forms of microvesicles, one derived from the surface membrane (between 0.1-1 μm), which we term plasma membrane-derived vesicles (PMVs) and exosomes (50-100nm) released by exocytosis. Much work has been documented on the release of PMVs, using various stimuli, and the roles they play in disease, but comparatively little is available on inhibition of PMV release. Although upon stimulation cells release exosomes in addition to PMVs, little has been reported on ways of differentiating between these two microvesicle types. Our aim was therefore to identify inhibitors of PMV release and to effectively differentiate between PMVs and exosomes. Methyl-β -cyclodextrin, an inhibitor of lipid rafts, calpeptin, which inhibits calpain and Rho-kinase inhibitor, Y-27632 were found to inhibit effectively the release of PMVs. Exosomes separated from PMVs by sucrose gradient were confirmed by electron microscopy and compared to PMVs were found to express less phosphatidylserine, but more CD63. Of the various cytokines carried by PMVs and exosomes, macrophage migration inhibition factor was found at a four-fold higher level in PMVs. Source of Research Support: Royal Society, London.

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Cosnier, Serge, Paulo Henrique Buzzetti, Yannig Nedellec, Monica Brachi, Karine Gorgy, Chantal Gondran, Dan Shan et Redouane Borsali. « (Keynote) Bioelectrocatalytic Systems Based on Microcapsules, Glyconanoparticles and Microcavities ». ECS Meeting Abstracts MA2022-01, n^o 49 (7 juillet 2022) : 2079. http://dx.doi.org/10.1149/ma2022-01492079mtgabs.

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For four decades, the functionalization of electrodes by biomaterials based on electrogenerated polymers, carbon nanotubes and / or nano-objects, was widely used in the field of analytical chemistry and energy conversion. Recently, we redesigned enzymatic bioelectrodes in order to produce original objects. An innovative concept of reagentless biosensors based on enzymatic reduction of oxygen was developed by trapping and releasing the substrate of the enzyme (catechol) from the structure of the biosensor. A polyurethane support modified by two perforated microcapsules filled with catechol was easily transformed into a bioelectrode by the successive deposition of multiwalled carbon nanotubes and a mixture of laponite clay and tyrosinase enzyme [1]. On the other hand, the development of glyconanoparticles resulting from the self-assembly of block copolymers composed of polystyrene and cyclodextrin as an inclusion site will be reported. These glyconanoparticles, which are stable in suspension in aqueous media, have an outer layer composed of cyclodextrin [2]. The latter allows a post-functionalization of the nanoparticle by hydrophobic molecules through host-guest interactions. It appears that it is possible to modulate the site density of βCD at the surface of the shell of the hybrid glyconanoparticles while maintaining its inclusion properties. Moreover, the anchoring of glyconanoparticles to the surface of electrodes has been carried out by host-guest interactions with electrogenerated polymers. The efficient immobilization of the nanoparticles allows the anchoring of multilayers of biotinylated glucose oxidase. Finally, a new generation of bioelectrodes for oxygen reduction and electrical energy production will be described. This approach is based on the design of flat electrodes made of permeable and conductive materials defining a very thin microcavity with a large surface area containing, in a microvolume, enzymes in powder form. The concept has been demonstrated with bilirubin oxidase (BOD) for the electroenzymatic reduction of oxygen in water. Besides the influence of the amount of enzyme trapped in the microcavity on the performance of the bioelectrode, the functionalization of the electrodes by adsorption of redox mediators or compounds allowing an orientation of the BOD favorable to electron transfer was also explored. After 5 months of storage in an aqueous buffer, the bioelectrode exhibits 20% of its initial electro-enzymatic activity. Y. Nedellec, C. Gondran, K. Gorgy, S. MC Murtry, O. El Mazria, P. Agostini, S. Cosnier. Biosens. Bioelectron., 180, 113137-113141(2021). M. Carrière, P. H. M. Buzzetti, K. Gorgy, M. Mumtaz, C. Travelet, R. Borsali, S. Cosnier. Nanomaterials 11 (2021) 1162. doi.org/10.3390/nano11051162.

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Sommer, Bettina, Luis M. Montaño, Verónica Carbajal, Edgar Flores-Soto, Alicia Ortega, Ricardo Ramírez-Oseguera, Claudine Irles, Ahmed F. El-Yazbi, Woo Jung Cho et Edwin E. Daniel. « Extraction of membrane cholesterol disrupts caveolae and impairs serotonergic (5-HT2A) and histaminergic (H1) responses in bovine airway smooth muscle : role of Rho-kinase ». Canadian Journal of Physiology and Pharmacology 87, n^o 3 (mars 2009) : 180–95. http://dx.doi.org/10.1139/y08-114.

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Some receptors and signaling molecules, such as Rho-kinase (ROCK), localize in caveolae. We asked whether the function of histamine receptors (H1) and 5-hydroxytryptamine (serotonin) receptors (5-HT2A) in bovine tracheal smooth muscle are modified after caveolae disruption and if so, whether the altered ROCK activity plays a role in this modification. Methyl-β-cyclodextrin (MβCD), used to deplete membrane cholesterol, was shown to disrupt caveolae and diminish sustained contractions to histamine (∼80%), 5-HT (100%), α-methyl-5-HT (100%), and KCl (∼30%). Cholesterol-loaded MβCD (CL-MβCD) restored the responses to KCl and partially restored the responses to agonists. ROCK inhibition by Y-27632 diminished contractions to histamine (∼85%) and 5-HT (∼59%). 5-HT or histamine stimulation augmented ROCK activity. These increases were reduced by MβCD and partially reestablished by CL-MβCD. The increase in intracellular Ca2+ that was induced by both agonists was reduced by MβCD. The presence of caveolin-1 (Cav-1), H1, 5-HT2A, and ROCK1 was corroborated by immunoblotting of membrane fractions from sucrose gradients and by confocal microscopy. H1 receptors coimmunoprecipitated with Cav-1 in caveolar and noncaveolar membrane fractions, whereas 5-HT2A receptors appeared to be restricted to noncaveolar membrane fractions. We conclude that caveolar and cholesterol integrity are indispensable for the proper functionality of the H1 and 5-HT2A receptors through their Rho/ROCK signaling.

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Saksena, Seema, Sangeeta Tyagi, Sonia Goyal, Ravinder K. Gill, Waddah A. Alrefai, K. Ramaswamy et Pradeep K. Dudeja. « Stimulation of apical Cl−/HCO3−(OH−) exchanger, SLC26A3 by neuropeptide Y is lipid raft dependent ». American Journal of Physiology-Gastrointestinal and Liver Physiology 299, n^o 6 (décembre 2010) : G1334—G1343. http://dx.doi.org/10.1152/ajpgi.00039.2010.

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Neuropeptide Y (NPY), an important proabsorptive hormone of the gastrointestinal tract has been shown to inhibit chloride secretion and stimulate NaCl absorption. However, mechanisms underlying the proabsorptive effects of NPY are not fully understood. The present studies were designed to examine the direct effects of NPY on apical Cl−/HCO3−(OH−) exchange activity and the underlying mechanisms involved utilizing Caco2 cells. Our results showed that NPY (100 nM, 30 min) significantly increased Cl−/HCO3−(OH−) exchange activity (∼2-fold). Selective NPY/Y1 or Y2 receptor agonists mimicked the effects of NPY. NPY-mediated stimulation of Cl−/HCO3−(OH−) exchange activity involved the ERK1/2 MAP kinase-dependent pathway. Cell surface biotinylation studies showed that NPY does not alter DRA (apical Cl−/HCO3−(OH−) exchanger) surface expression, ruling out the involvement of membrane trafficking events. Interestingly, DRA was found to be predominantly expressed in the detergent-insoluble (DI) and low-density fractions (LDF) of human colonic apical membrane vesicles (AMVs) representing lipid rafts. Depletion of membrane cholesterol by methyl-β-cyclodextrin (MβCD, 10 mM, 1 h) remarkably decreased DRA expression in the DI fractions. Similar results were obtained in Triton-X 100-treated Caco2 plasma membranes. DRA association with lipid rafts in the DI and LDF fractions of Caco2 cells was significantly enhanced (∼45%) by NPY compared with control. MβCD significantly decreased Cl−/HCO3−(OH−) exchange activity in Caco2 cells as measured by DIDS- or niflumic acid-sensitive 36Cl− uptake (∼50%). Our results demonstrate that NPY modulates Cl−/HCO3−(OH−) exchange activity by enhancing the association of DRA with lipid rafts, thereby resulting in an increase in Cl−/HCO3−(OH−) exchange activity. Our findings suggest that the alteration in the association of DRA with lipid rafts may contribute to the proabsorptive effects of NPY in the human intestine.

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Bearden, Aaron A., Emily M. Stewart, Candace C. Casher, Meredith A. Shaddix, Amber C. Nobles et Robin J. Mockett. « Effects of Target of Rapamycin and Phosphatidylinositol 3-Kinase Inhibitors and Other Autophagy-Related Supplements on Life Span in y w Male Drosophila melanogaster ». International Journal of Molecular Sciences 25, n^o 21 (26 octobre 2024) : 11504. http://dx.doi.org/10.3390/ijms252111504.

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Various dietary supplements have been shown to extend the life span of Drosophila melanogaster, including several that promote autophagy, such as rapamycin and spermidine. The goal of the study presented here was to test numerous additional potential anti-aging supplements, primarily inhibitors of the target of rapamycin (TOR) and/or phosphatidylinositol 3-kinase (PI3K). Using a single, comparatively long-lived y w test strain, screening was performed in male flies supplemented either throughout adulthood or, in a few cases, beginning in middle or late adult life, with concentrations spanning 4–6 orders of magnitude in most cases. Supplementation with PP242 and deferiprone, an iron chelator, beginning in late adult life had no positive effect on life span. Lifelong supplementation with Ku-0063794, LY294002, PX-866-17OH, Torin2 and WYE-28 had no effect at any dose. Rapamycin, spermidine and wortmannin all had significant life-shortening effects at the highest doses tested. AZD8055, PI-103 hydrochloride and WYE-132 yielded slight beneficial effects at 1–2 doses, but only 100 nM AZD8055 was confirmed to have a minor (1.3%) effect in a replicate experiment, which was encompassed by other control groups within the same study. These compounds had no effect on fly fecundity (egg laying) or fertility (development of progeny to adulthood), but equivalent high doses of rapamycin abolished fertility. The solvent DMSO had no significant effect on life span at the concentrations used to solubilize most compounds in the fly medium, but it drastically curtailed both survival and fertility at higher concentrations. 2-Hydroxypropyl-β-cyclodextrin also failed to extend the life span when provided throughout adulthood or beginning in mid-adult life. Collectively, the results suggest that inhibition of the TOR/PI3K pathway and autophagy through dietary intervention is not a straightforward anti-aging strategy in Drosophila and that further extension of life is difficult in comparatively long-lived flies.

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Thi Lan, Pham, Pham Long Khanh, Nguyen Thi Ngoan, Le Hai Khoa, Vu Xuan Minh, Nguyen Anh Son et Tran Dai Lam. « Improved water solubility of quercetin by preparing complexation with cyclodextrins in binary solvent ». Vietnam Journal of Biotechnology 18, n^o 4 (24 mai 2021) : 701–8. http://dx.doi.org/10.15625/1811-4989/18/4/15115.

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The antioxidant capacity of polyphenols have been widely used in food and pharmaceutical industries. Quercetin (Quer) is a polyphenolic flavonoid that shows several biological effects such as antioxidant, antitumor, antibacterial and antiproliferative effects both in-vitro and in-vivo. However, the solubility of quercetin in water is poor. Thus, it is essential to improve solubility of quercetin in pharmaceuticals by making its complexation with other compounds. In this study, the synthesis of the 2-hydroxypropyl-β-cyclodextrin complex with quercetin (Quer-HPβCD) in the form of nanoparticles in water-ethanol solvents has been carried out. The results showed that the obtained yield of (Quer-HPβCD) complexation in binary solvent was greater than that in pure water. The highest Y value was 80% in a binary solvent with 20% v/v of ethanol. The composition, morphology, structural and thermodynamic properties of the nanoparticles Quer-HPβCD have been determined. This study demonstrated that using mixed water- ethanol solvent and lyophilization technique was able to produce quercetin nanoparticles with significantly smaller particle size. The nanoparticles have a spherical shape with an average size of about 40-60 nm. The results of the phase solubility diagram showed that in water the solubility of quercetin increased and linearly depended on the concentration of host’s molecule while Quer and HP-βCD obtained a 1:1 stoichiometric complex. The stability constant of (Quer-HPβCD) complex was found to be logK = 2.56. The Gibbs energy change of the complexation reaction was found to be -14.60 kJ/mol.

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Bhattacharya, Bishnupriya, et Polly Roy. « Bluetongue Virus Outer Capsid Protein VP5 Interacts with Membrane Lipid Rafts via a SNARE Domain ». Journal of Virology 82, n^o 21 (27 août 2008) : 10600–10612. http://dx.doi.org/10.1128/jvi.01274-08.

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ABSTRACT Bluetongue virus (BTV) is a nonenveloped double-stranded RNA virus belonging to the family Reoviridae. The two outer capsid proteins, VP2 and VP5, are responsible for virus entry. However, little is known about the roles of these two proteins, particularly VP5, in virus trafficking and assembly. In this study, we used density gradient fractionation and methyl beta cyclodextrin, a cholesterol-sequestering drug, to demonstrate not only that VP5 copurifies with lipid raft domains in both transfected and infected cells, but also that raft domain integrity is required for BTV assembly. Previously, we showed that BTV nonstructural protein 3 (NS3) interacts with VP2 and also with cellular exocytosis and ESCRT pathway proteins, indicating its involvement in virus egress (A. R. Beaton, J. Rodriguez, Y. K. Reddy, and P. Roy, Proc. Natl. Acad. Sci. USA 99:13154-13159, 2002; C. Wirblich, B. Bhattacharya, and P. Roy J. Virol. 80:460-473, 2006). Here, we show by pull-down and confocal analysis that NS3 also interacts with VP5. Further, a conserved membrane-docking domain similar to the motif in synaptotagmin, a protein belonging to the SNARE (soluble N-ethylmaleimide-sensitive fusion attachment protein receptor) family was identified in the VP5 sequence. By site-directed mutagenesis, followed by flotation and confocal analyses, we demonstrated that raft association of VP5 depends on this domain. Together, these results indicate that VP5 possesses an autonomous signal for its membrane targeting and that the interaction of VP5 with membrane-associated NS3 might play an important role in virus assembly.

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de la Rosa, Laura A., Gilberto Mercado-Mercado, Joaquín Rodrigo-García, Gustavo A. González-Aguilar et Emilio Alvarez-Parrilla. « Peach polyphenol oxidase inhibition by 𝛃-cyclodextrin and 4-hexylresorcinol is substrate dependent La inhibición de la polifenoloxidasa de durazno por 𝛃-ciclodextrina y 4-hexilresorcinol es dependiente del sustrato ». CyTA - Journal of Food 8, n^o 2 (août 2010) : 87–93. http://dx.doi.org/10.1080/19476330903146013.

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Zemlyanoy, R. A., K. T. Erimbetov, A. V. Fedorova, A. Ya Goncharova et E. V. Bondarenko. « Development of the active clatrate of 3- (2-phenylethyl) -2-thioxo-1,3 thiazolidin-4-one with β-cyclodextrin and study of its bioavailability. » International bulletin of Veterinary Medicine 3 (2020) : 58–64. http://dx.doi.org/10.17238/issn2072-2419.2020.3.58.

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At present, the class of rhodanine com-pounds containing 4-oxo-2-thioxo-1,3-thiazolidine residues is very promising in the development of medical and veterinary drugs. The purpose of the work is to develop a chemical compound 3- (2-phenylethyl) -2-thioxo-1,3 thiazolidin-4-one (XC-3-2-FE-2-TO-1,3T-4-OH) based on clathrate with β- cyclodextrin (CD) - a supramolecular com-pound (CMC) with improved biopharmaceu-tical properties (solubility and bioavailabil-ity). The lattice clathrates KhS-3-2-FE-2-TO-1,3T-4-OHa with CD were synthesized at the ratios of their masses 1: 5 and 1:10. CMC is a crystalline powder of white with a yellow tint with a particle size of less than 100 nm. For the first time, a method was developed for the quantitative determination of CHS-3-2-FE-2-TO-1,3T-4-OHa in the blood plasma of dogs by high performance liquid chromatography (HPLC). In the range of 0.2-4.0 μg / ml, the calibration curve is linear for ChS-3-2-FE-2-TO-1,3T-4-OH, while the regression equation is described by y = 3.977 + 30.343 × X, s the coefficient of accuracy of the approximation equal to R2 = 0.999. The lower limit of quantitative detec-tion is 10 ng / ml. The average maximum concentrations (Cmax) of ChC-3-2-FE-2-TO-1,3T-4-OHa in the blood plasma of dogs with it, as well as in the form of a clathrate single oral administration, respectively, were 0.66 ± 0, 25 and 3.03 ± 0.82 μg / ml (P≤0.05). The average values of the parame-ter AUC (0 → t) with the introduction of ChS-3-2-FE-2-TO-1,3T-4-On and its clath-rate with CD, respectively, were 4.07 ± 2.15 μg × h / ml and 24.58 ± 5.66 μg × h / ml (P≤0.05). According to a pharmacokinetic study, the best bioavailability (DB) is pos-sessed by the C-3-2-FE-2-TO-1,3T-4-OHa clathrate with CD in a ratio of 1: 5, the ob-tained DB value is 6.4 times higher than the same the value of the original compound. It was concluded that, in terms of biopharma-ceutical properties, the most promising agent for medical and veterinary use is the XC-3-2-FE-2-TO-1,3T-4-OHa clathrate with CD with a mass ratio of 1: 5 and an average par-ticle size of 40.5 nm

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Tân, Phạm Thị Hồng. « Tổng hợp nano artesunate ứng dụng trong y sinh học ». KỸ THUẬT VÀ CÔNG NGHỆ 14, n^o 1 (6 juin 2020) : 39–47. http://dx.doi.org/10.46223/hcmcoujs.tech.vi.14.1.446.2019.

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Trong bài báo này, hạt nano β-cyclodextrin–alginate–artesunate đã được tổng hợp với kích thước từ 20nm – 80nm, kích thước hạt khá đồng đều ứng dụng làm tăng khả năng dẫn truyền thuốc. Đặc điểm hình thái và cấu trúc của hạt nano được xác định bằng SEM và TEM. Bằng phương pháp sắc ký bản mỏng TLC, vị trí vết của mẫu chuẩn artesunate và mẫu thử nano β-cyclodextrin–alginate–artesunate ngang bằng nhau, chứng tỏ được sự có mặt của artesunate trong mẫu nano tổng hợp được.

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Ghanghoria, Raksha, Prashant Kesharwani, Hrushikesh Bharat Agashe et N. K. Jain. « Transdermal delivery of cyclodextrin-solubilized curcumin ». Drug Delivery and Translational Research 3, n^o 3 (28 novembre 2012) : 272–85. http://dx.doi.org/10.1007/s13346-012-0114-y.

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Vyas, Amber, Shailendra Saraf et Swarnlata Saraf. « Cyclodextrin based novel drug delivery systems ». Journal of Inclusion Phenomena and Macrocyclic Chemistry 62, n^o 1-2 (23 mai 2008) : 23–42. http://dx.doi.org/10.1007/s10847-008-9456-y.

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Jaimes, Nancy, Siham Salmen, Melisa Carolina Colmenares, Ana Esperanza Burgos, Lenka Tamayo, Rosa Virginia Mendoza et Astrid Cantor. « Cytotoxic effect of palladium (II) inclusion compounds in beta-cyclodextrin ». Biomédica 36, n^o 4 (1 décembre 2016) : 603. http://dx.doi.org/10.7705/biomedica.v36i4.2880.

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Introducción. Las tiosemicarbazonas y sus complejos de paladio (II) poseen actividad antineoplásica con pocos efectos secundarios, por lo cual se las considera como una nueva alternativa terapéutica. Sin embargo, existen diferencias en los rangos de la concentración inhibitoria media (CI50) asociada a la divergencia estructural y la solubilidad de los complejos, así como a la sensibilidad de los blancos celulares. La inclusión de fármacos en la beta-ciclodextrina con fines terapéuticos ha mejorado su solubilidad y estabilidad, pero los efectos de su combinación con los complejos de paladio (II) y las tiosemicarbazonas no se han comprobado aún.Objetivo. Estudiar el efecto citotóxico de los complejos de paladio en la beta-ciclodextrina.Materiales y métodos. La actividad citotóxica de los complejos de paladio en la beta-ciclodextrina se evaluó en la línea celular de cáncer de mama (MCF-7), empleando el método de la sulforodamina B.Resultados. Los ligandos MePhPzTSC y Ph2PzTSC, sus complejos de paladio (II) libres e incluidos en la beta-ciclodextrina y el cisplatino mostraron actividad citotóxica en la línea celular MCF-7; sin embargo, la citotoxicidad fue mayor con la inclusión en la beta-ciclodextrina ([Pd(MePhPzTSC)2]•ß-CD y [Pd(Ph2PzTSC)2]•ß-CD). La concentración inhibitoria media (CI50) para estos complejos se obtuvo en concentraciones de 0,14 y 0,49 μM, y con dosis hasta cinco veces inferiores comparadas con las concentraciones de los ligandos libres (1,4 y 2,9 μM), de los complejos de paladio (II) libres (0,57 y 1,24 μM) y del cisplatino (6,87 μM).Conclusiones. El uso de la beta-ciclodextrina mejoró significativamente la actividad citotóxica de las tiosemicarbazonas y sus complejos de paladio (II), lo cual probablemente está asociado al incremento de la solubilidad y biodisponibilidad del compuesto, estrategia que se puede sugerir para el diseño de futuros fármacos antineoplásicos.

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Deeble, David J., Eberhard Bothe, Heinz-Peter Schuchmann, Barry J. Parsons, Glyn O. Phillips et Clemens von Sonntag. « The Kinetics of Hydroxyl-Radical-Induced Strand Breakage of Hyaluronic Acid. A Pulse Radiolysis Study Using Conductometry and Laser-Light-Scattering ». Zeitschrift für Naturforschung C 45, n^o 9-10 (1 octobre 1990) : 1031–43. http://dx.doi.org/10.1515/znc-1990-9-1016.

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Abstract Hydroxyl radicals were generated radiolytically in N2O -and N2O / O2(4: 1)-saturated aqueous solutions of hyaluronic acid. The hydroxyl radicals react rapidly with hyaluronic acid mainly by abstracting carbon-bound H atom s. As a consequence of subsequent free-radical reactions, chain breakage occurs the kinetics of which has been followed using the pulse radio lysis technique. In the absence of oxygen, strand breakage was followed by the change in conductivity in duced by the release of cationic counterions condensed at the surface of hyaluronic acid which is a polyanion consisting of subunits of glucuronic acid alternating with N-acetyl-glucosamine. It appears that strand breakage is not due to one single first-order process, however, the con tributions of the different com ponents cannot be adequately resolved. At pH7 the overall half-life is 1.4 ms, in both acid and basic solutions the rate of free-radical induced strand breakage is accelerated (at pH 4.8, t1/2 = 0.6 ms; at pH 10, t1/2 = 0.18 ms). In the absence of oxygen there is no effect of dose rate on the kinetics of strand breakage. In the presence of oxygen in addition to conductom etric detection, strand breakage was also followed by changes in low-angle laser light-scattering. These two techniques are complementary in that in this system the conductometry requires high doses per pulse while the light-scat tering technique is best operated in the low -dose range. In the presence of oxygen a pro nounced dose-rate effect is observed, e.g. at pH 9.7 after a dose of 9.4 Gy the overall half-time is approx. 0.5 s, while after a dose of 6.6 Gy the half-time is approx. 0.23 s. Both the yield and the rate of strand breakage increase with increasing pH, e.g. at pH 7 G(strand breaks) = 0.7 × 10-7 mol J-1 and at pH 10.4, 4.8 × 10-7 mol J-7. The radiolytic yields of CO2, H2O2, organic hydroperoxides, O2·- and oxygen consum ption have been determined in y-irradiated N2O/ 0 2(4: 1)-saturated solutions of both hyaluronic acid and β-cyclodextrin.

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Thi, Thao Do, Koen Nauwelaerts, Luc Baudemprez, Michiel Speybroeck, Jan Vermant, Patrick Augustijns, Pieter Annaert, Johan Martens, Jan Humbeeck et Guy den Mooter. « Comparison between 2-hydroxypropyl-β-cyclodextrin and 2-hydroxypropyl-γ-cyclodextrin for inclusion complex formation with danazol ». Journal of Inclusion Phenomena and Macrocyclic Chemistry 71, n^o 1-2 (25 janvier 2011) : 137–47. http://dx.doi.org/10.1007/s10847-010-9917-y.

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Tomita, Kenji, Takaaki Tanaka, Yoshito Fujita et Kazuhiro Nakanishi. « Some factors affecting the formation of γ-cyclodextrin using cyclodextrin glycosyltransferase from Bacillus sp. AL-6 ». Journal of Fermentation and Bioengineering 70, n^o 3 (janvier 1990) : 190–92. http://dx.doi.org/10.1016/0922-338x(90)90185-y.

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Fenger, Thomas Hauch, et Mikael Bols. « Simple cyclodextrin aldehydes as excellent artificial oxidases ». Journal of Inclusion Phenomena and Macrocyclic Chemistry 69, n^o 3-4 (30 mars 2010) : 397–402. http://dx.doi.org/10.1007/s10847-010-9771-y.

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UEKAMA, KANETO, FUMITOSHI HIRAYAMA et HIDETOSHI ARIMA. « Recent Aspect of Cyclodextrin-Based Drug Delivery System ». Journal of Inclusion Phenomena and Macrocyclic Chemistry 56, n^o 1-2 (26 avril 2006) : 3–8. http://dx.doi.org/10.1007/s10847-006-9052-y.

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Pishtiyski, Ivan, Viara Popova et Boriana Zhekova. « Characterization of Cyclodextrin Glucanotransferase Produced by Bacillus megaterium ». Applied Biochemistry and Biotechnology 144, n^o 3 (7 août 2007) : 263–72. http://dx.doi.org/10.1007/s12010-007-8009-y.

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Yu, Yong, Jiguang Li, Yan Sun, Qianqing Liang, Xiaoming Peng, Yansheng Liu et Yufeng Hu. « Solubility of β-cyclodextrin in different mixed solvents ». Petroleum Science 5, n^o 3 (août 2008) : 263–68. http://dx.doi.org/10.1007/s12182-008-0044-y.

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Canipelle, M., D. Landy et S. Fourmentin. « Improved aqueous Cannizzaro reaction in presence of cyclodextrin ». Journal of Inclusion Phenomena and Macrocyclic Chemistry 69, n^o 3-4 (9 février 2010) : 349–53. http://dx.doi.org/10.1007/s10847-010-9747-y.

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Ammar, H. O., M. Ghorab, A. A. Mahmoud, T. S. Makram et S. H. Noshi. « Topical liquid crystalline gel containing lornoxicam/cyclodextrin complex ». Journal of Inclusion Phenomena and Macrocyclic Chemistry 73, n^o 1-4 (26 octobre 2011) : 161–75. http://dx.doi.org/10.1007/s10847-011-0039-y.

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