Krumkacheva O.A.,Novosibirsk State University |
Fedin M.V.,Russian Academy of Sciences |
Polovyanenko D.N.,RAS Institute of Organic Chemistry |
Jicsinszky L.,CycloLab Ltd |
And 2 more authors.
Journal of Physical Chemistry B | Year: 2013
Design of the new spin-labeled cyclodextrins can significantly extend the functionality of nitroxides. A series of new complexes based on fully methylated cyclodextrin (TRIMEB) covalently bound to the piperidine, pyrroline, pyrrolidine, and pH-sensitive imidazoline type nitroxides has been synthesized and studied using pulse and continuous wave electron paramagnetic resonance (EPR). The influence of the radical and linker properties on the structure of complexes formed has been investigated. Using the electron spin echo envelope modulation technique, we have analyzed quantitatively the accessibility of radicals to solvent molecules in studied complexes depending on the structure and length of the linkers. In all studied systems we observed different types of equilibria between conformations with radical fragment being outside the TRIMEB cavity and radical fragment capping the cavity of TRIMEB. The observed guest-induced shift of equilibrium toward the complex with radical capping TRIMEB cavity was explained by a change of macrocyclic configuration of TRIMEB. Complex with the -NH-CO- linker has been found most perspective for the applications requiring close location of nitroxide to the inclusion complex of TRIMEB. Using continuous wave EPR, we have shown that the pH-sensitive radical covalently bound to TRIMEB maintains its pH-sensitivity, but this complexation does not reduce radical reduction rate in the reaction with ascorbic acid. © 2013 American Chemical Society. Source
Horvath G.,University of Pecs |
Kemeny A.,University of Pecs |
Bartho L.,University of Pecs |
Molnar P.,University of Pecs |
And 8 more authors.
Journal of Molecular Neuroscience | Year: 2015
Mechanisms of the potent anti-inflammatory actions of carotenoids are unknown. Since carotenoids are incorporated into membranes, they might modulate transient receptor potential ankyrin 1 and vanilloid 1 (TRPA1 and TRPV1) activation predominantly on peptidergic sensory nerves. We therefore investigated the effects of three carotenoids (β-carotene, lutein and lycopene) on cutaneous neurogenic inflammation. Acute neurogenic edema and inflammatory cell recruitment were induced by smearing the TRPA1 agonist mustard oil (5 %) or the TRPV1 activator capsaicin (2.5 %) on the mouse ear. Ear thickness was then determined by micrometry, microcirculation by laser Doppler imaging and neutrophil accumulation by histopathology and spectrophotometric determination of myeloperoxidase activity. The effects of lutein on the stimulatory action of the TRPA1 agonist mustard oil were also tested on the guinea-pig small intestine, in isolated organ experiments. Mustard oil evoked 50–55 % ear edema and granulocyte influx, as shown by histology and myeloperoxidase activity. Swelling was significantly reduced between 2 and 4 h after administration of lutein or β-carotene (100 mg/kg subcutane three times during 24 h). Lutein also decreased neutrophil accumulation induced by TRPA1 activation, but did not affect mustard oil-evoked intestinal contraction. Lycopene had no effect on any of these parameters. None of the three carotenoids altered capsaicin-evoked inflammation. It is proposed that the dihydroxycarotenoid lutein selectively inhibits TRPA1 activation and consequent neurogenic inflammation, possibly by modulating lipid rafts. © 2015, Springer Science+Business Media New York. Source
Uccello-Barretta G.,University of Pisa |
Evangelisti C.,University of Pisa |
Balzano F.,University of Pisa |
Vanni L.,University of Pisa |
And 2 more authors.
Carbohydrate Research | Year: 2011
The complexation of heptakis(6-deoxy-6-thio)cyclomaltoheptaose to gold nanoparticles prepared by using the Metal Vapour Synthesis (MVS) led to water soluble gold nanoaggregates, thermally stable at 25 °C. The role of gold concentration in the MVS-derived starting solution as well as of the cyclodextrin to gold molar ratio on the size of cyclodextrin-capped gold nanoparticles were investigated. The ability of cyclodextrin bonded to gold nanoparticles to include deoxycytidine was also probed in comparison with that of 1-thio-β-d-glucose sodium salt. © 2011 Elsevier Ltd. All rights reserved. Source
Sohajda T.,Semmelweis University |
Hu W.H.,Chinese Academy of Sciences |
Zeng L.L.,Chinese Academy of Sciences |
Li H.,Chinese Academy of Sciences |
And 3 more authors.
Electrophoresis | Year: 2011
An aqueous capillary electrophoretic method was developed for chiral analysis of the novel anti-diabetic drug, sitagliptin. The acid-base profiling of the analyte was carried out using both capillary electrophoresis and nuclear magnetic resonance pH titrations. The apparent complex stability and chiral separation properties were investigated with 30 different cyclodextrins under acidic conditions. The effect of concentration and pH of the BGE, temperature of the capillary, and the type and concentration of the chiral selector on the enantiomer resolution were thoroughly investigated. The effects of dual cyclodextrin systems on separation were also extensively studied. Complete separation of racemic sitagliptin with good resolution (R S=2.24) was achieved within a short time (15min) with optimized parameters (10°C, pH=4.4, 40mM phosphate buffer) of a sulfobutylether-β-cyclodextrin (averaged degree of substitution ~4) and native β-cyclodextrin dual system. The averaged stoichiometry of the inclusion complex was determined using the Job plot method with both 1H and 19F NMR experiments and resulted in a 1:1 complex. The structure of the inclusion complex was elucidated using 2-D ROESY NMR experiments. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source
Daruhazi A.E.,Semmelweis University |
Kiss T.,Debrecen University |
Vecsernyes M.,Debrecen University |
Szente L.,CycloLab Ltd |
And 2 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2013
Isoflavonoids are widespread constituents in medical plants especially in legumes (Fabaceae), but occur in other different plant families as well (Rosaceae, Iridaceae, Amaranthaceae). Their antioxidant, estrogen-like, anti-inflammatory and analgesic effects make them promising compounds in therapy of important disorders especially in estrogen related diseases. Poor solubility in aqueous system of genistein and daidzein needs a solubility enhancement for pharmaceutical use. These compounds are suitable guest molecules for inclusion complex formation with cyclodextrins (CDs) considering matching their size and polarity.The molecular encapsulation with beta-cyclodextrin (β-CD), gamma-cyclodextrin (γ-CD), hydroxypropyl-beta-cyclodextrin (HP-β-CD) and random methyl-beta cyclodextrin (RAMEB-CD) results in a solid, molecularly dispersed form and in a significantly improved aqueous solubility of genistein and daidzein. Determining enhancement in solubility and bioavailability we investigated the transport of these inclusion complexes across Caco-2 cell line comparing that of the pure compounds and found significant improving effect of the different CD derivatives on membrane permeation of the two isoflavone aglycons. © 2013 Elsevier B.V. Source