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Synthesis and spectral investigation of Al(III) catechin/beta-cyclodextrin and Al(III) quercetin/beta-cyclodextrin inclusion compounds

DIAS, Karina; NIKOLAOU, Sofia; GIOVANI, Wagner F. De
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
ENG
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Al-catechin/beta-cyclodextrin and Al-quercetin/beta-cyclodextrin (beta-CD) inclusion compounds were synthesized and characterized by IR, UV-vis, H-1 and C-13 NMR and TG and DTA analyses. Because quercetin is sparingly soluble in water, the stability constants of the Al-quercetin/beta-CD and Al-catechin/beta-CD compounds were determined by phase solubility studies. The A(L)-type diagrams indicated the formation of 1:1 inclusion compounds and allowed calculation of the stability constants. The thermodynamic parameters were obtained from the dependence of the stability constants on temperature and results indicated that the formation of the inclusion compounds is an enthalpically driven process. The thermal decomposition of the solid Al-quercetin/beta-CD and Al-catcchin/beta-CD inclusion compounds took place at different stages, compared with the respective precursors, proving that an inclusion complexation process really occurred. (C) 2007 Published by Elsevier B.V.

Study of spectroscopic properties of Europium (III) Tris(beta-diketonate) complex and alpha-Cyclodextrin in aqueous medium

RIBEIRO, Anderson O.; SERRA, Osvaldo A.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
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The solubilization of an europium (III) beta-diketonate chelate in aqueous medium and the changes in its photophysical properties upon its inclusion into an alpha-cyclodextrin hydrophobic cavity are described. The complex [Eu(tta)(3)center dot(H(2)O)(2)] (tta = 4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3-dione) was synthesized, characterized, and incorporated into the hydrophobic cavity by stirring in an alpha-cyclodextrin aqueous solution. The inclusion was confirmed by (1)H NMR, and the stoichiometry of association was obtained by the Job method. The maximum in the excitation spectrum of the alpha-CD inclusion compound in aqueous solution was shifted 28 nm compared with the maximum of non alpha-CD complex. The emission spectrum of the association is similar to that of the free solid complex and displays the characteristic (5)D(0) -> (7)F(0-4) Eu(3+) transitions.; FAPESP; CAPES; CNPq

Desenvolvimento e caracterização físico-química de um sistema de liberação controlada da hialuronidase incluída em hidroxipropil--ciclodextrina; Development and physical-chemical characterization of a controlled delivery system of hyaluronidase included in hydroxypropyl- - cyclodextrin

Murakami, Victor Oliveira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 21/09/2012 PT
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A hialuronidase é uma enzima que vem sendo utilizada como adjuvante anestésico na oftalmologia há décadas para melhorar a eficácia anestésica, por aumentar a difusão do anestésico para o nervo. Na odontologia, quando foi injetada concomitantemente ao anestésico local em bloqueio pterigomandibular, reduziu a duração da anestesia e causou trismo, pois no momento inicial da anestesia ainda havia provavelmente muito anestésico no sítio da injeção, dispersando-o para tecidos adjacentes. Entretanto, em outro protocolo, a enzima foi injetada em outro momento, antes do término do efeito anestésico e, não induziu efeitos adversos e ainda aumentou a duração de ação, provavelmente, por difundir apenas o anestésico remanescente para o nervo. A fim de evitar uma nova puntura para injetar a hialuronidase, a enzima poderia ser incorporada a um carreador, que modularia a sua liberação tardiamente, simulando o protocolo anterior. O desenvolvimento desse sistema de liberação controlada da enzima, a ser futuramente associada aos anestésicos locais visa ainda diminuir a dose necessária para o bloqueio completo, diminuindo assim o risco de toxicidade sistêmica. Este estudo laboratorial teve por objetivo desenvolver o complexo de inclusão utilizando a como carreador da hialuronidase...

Análise funcional do bloqueio ciático em ratos com lidocaína associada à hialuronidase em complexação com hidroxipropil -  ß-ciclodextrina e citotoxicidade; Functional analysis of rat sciatic block with lidocaine associated to hyaluronidase in complexation with hydroxypropyl- ß-cyclodextrin and cytotoxicity

Carvalho, Carolina de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 13/03/2014 PT
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O uso da enzima hialuronidase como adjuvante do anestésico local está consagrado em oftalmologia, por melhorar a eficácia anestésica devido ao seu efeito difusor de fármacos, ocasionado pela quebra temporária do hialuronan (ácido hialurônico) que é o principal constituinte de tecidos conectivos. Em odontologia, a utilização da enzima como adjuvante no bloqueio do nervo alveolar inferior não apresentou vantagens quando injetada concomitante ao anestésico local, resultando em dor e trismo. Entretanto, com a utilização de um novo protocolo onde a aplicação da hialuronidase ocorria aos 30 min do início da anestesia, prolongou o efeito anestésico e sem ocorrência de efeitos adversos. Este protocolo oferecia a vantagem de evitar complementação anestésica reduzindo os riscos de toxicidade local e sistêmica, porém ainda havia a desvantagem da necessidade de uma nova puntura para aplicação da enzima. Surgiu a hipótese de se manter os benefícios desse protocolo com o uso da hialuronidase, de prolongar a duração da ação anestésica, injetando-a concomitantemente ao anestésico local, porém estando a enzima em um sistema de liberação lenta. Deste modo, a hialuronidase (75 UTR/ml) foi incorporada a uma nanopartícula...

Criopreservação do sêmen ovino com incorporação de colesterol por ciclodextrina; Criopreservation of ram semen with colesterol loaded cyclodextrin

Batissaco, Leonardo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 31/10/2014 PT
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A preocupação com a qualidade do sêmen ovino congelado tem sido motivo de muitas pesquisas, principalmente pela dificuldade da transposição cervical durante a inseminação artificial. Contudo, a inseminação intra-cervical é frequentemente usada em ovinos e resulta em redução da fertilidade com o uso do sêmen congelado. Neste sentido, esse estudo foi dividido em dois experimentos. No 1o experimento foi verificado o potencial da ciclodextrina pré-carregada com colesterol como aditivo ao diluidor na proteção da cinética espermática, integridade das membranas plasmática e acrossomal, função mitocondrial, capacitação espermática e produção de espécies reativas ao oxigênio (ROS) em espermatozoides criopreservados ovinos. Cinco ejaculados de seis carneiros (n = 30) foram divididos em três tratamentos: apenas diluidor (CON); diluidor + colesterol incorporado a ciclodextrina (CLC + CHO); e diluidor + ciclodextrina pura (CLCP). Após a diluição (50x106 espermatozóides/mL), o sêmen foi envasado em palhetas, identificado e criopreservado utilizando um sistema automatizado. Duas palhetas da mesma partida de cada tratamento foram descongeladas (a 37°C durante 30 segundos) e analisadas quanto motilidade (CASA), morfologia dos espermatozoides (DIC)...

Cyclodextrin Production by Bacillus lehensis Isolated from Cassava Starch: Characterisation of a Novel Enzyme

Blanco, Kate Cristina; Moraes, Flavio Faria de; Bernardi, Natalia Sozza; Braga Vettori, Mary Helen Palmuti; Monti, Rubens; Contiero, Jonas
Fonte: Czech Academy Agricultural Sciences Publicador: Czech Academy Agricultural Sciences
Tipo: Artigo de Revista Científica Formato: 48-53
ENG
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The properties of a previously unknown enzyme, denominated cyclodextrin glycosyltransferase, produced from Bacillus lehensis, were evaluated using affinity chromatography for protein purification. Enzyme characteristics (optimum pH and temperature; pH and temperature stability), the influence of substances on the enzyme activity, enzyme kinetics, and cyclodextrin production were analysed. Cyclodextrin glycosyltransferase was purified up to 320.74-fold by affinity chromatography using beta-cyclodextrin as the binder and it exhibited 8.71% activity recovery. This enzyme is a monomer with a molecular weight of 81.27 kDa, as estimated by SDS-PAGE. Optimum temperature and pH for cydodextrin glycosyltransferase were 55 degrees C and 8.0, respectively. The Michaelis-Menten constant was 8.62 g/l during maximum velocity of 0.858 g/l.h.

Cyclodextrin modulation of gallic acid in vitro antibacterial activity

Pinho, Eva; Soares, Graça M. B.; Henriques, Mariana
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2015 ENG
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The substitution of large spectrum antibiotics for natural bioactive molecules (especially polyphenolics) for the treatment of wound infections has come into prominence in the pharmaceutical industry. However, the use of such molecules depends on their stability during environmental stress and on their ability to reach the action site without losing biological properties. The application of cyclodextrins as a vehicle for polyphenolics protection has been documented and appears to enhance the properties of bioactive molecules. Therefore, the encapsulation of gallic acid, an antibacterial agent with low stability, by -cyclodextrin, (2-hydroxy) propyl--cyclodextrin and methyl--cyclodextrin, was investigated. Encapsulation by -cyclodextrin was confirmed for pH 3 and 5, with similar stability parameters. The (2-hydroxy) propyl--cyclodextrin and methyl--cyclodextrin interactions with gallic acid were only confirmed at pH 3. Among the three cyclodextrins, better gallic acid encapsulation were observed for (2-hydroxy) propyl--cyclodextrin, followed by -cyclodextrin and methyl--cyclodextrin. The effect of cyclodextrin encapsulation on the gallic acid antibacterial activity was also analysed. The antibacterial activity of the inclusion complexes was investigated here for the first time. According to the results...

Complexation of enalapril maleate with beta-cyclodextrin: NMR spectroscopic study in solution

Ali,Syed Mashhood; Maheshwari,Arti; Asmat,Fahmeena; Koketsu,Mamoru
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2006 PT
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A detailed NMR (¹H , COSY, ROESY) spectroscopic study of complexation of enalapril maleate with beta-cyclodextrin was carried out. The ¹H NMR spectrum of enalapril maleate confirmed the existence of cis-trans equilibrium in solution, possibly due to hindered rotation along the amide bond. The cis-trans ratio remained almost the same in the presence of beta-cyclodextrin but in one case it was found significantly different which suggests a catalytic role of beta-cyclodextrin in the isomerization. ¹H NMR titration studies confirmed the formation of an enalapril-beta-cyclodextrin inclusion complex as evidenced by chemical shift variations in the proton resonances of both the host and the guest. The stoichiometry of the complex was determined to be 2:1 (guest: host). The mode of penetration of the guest into the beta-cyclodextrin cavity as well as the structure of the complex were established using ROESY spectroscopy.

Evaluation of piroxicam-β-cyclodextrin as a preemptive analgesic in functional endoscopic sinus surgery

Keleş,G.T.; Topçu,I.; Ekici,Z.; Yentür,A.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2010 EN
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The preemptive analgesic efficacy and adverse effects of preoperatively administered piroxicam-β-cyclodextrin for post-endoscopic sinus surgery pain was determined in a prospective, double-blind, randomized, clinical study. Seventy-five American Society of Anesthesiologists status I-II patients, aged 18-65 years, were divided into three groups with similar demographic characteristics: group 1 received 20 mg piroxicam-β-cyclodextrin, group 2 received 40 mg piroxicam-β-cyclodextrin and group 3 received placebo orally before induction of general anesthesia. A blinded observer recorded the incidence and severity of pain at admission to the post-anesthesia care unit (PACU), at 15, 30, and 45 min in the PACU, and 1, 2, 4, 6, and 24 h postoperatively. All patients received patient-controlled morphine analgesia during the postoperative period and consumption was recorded for 24 h. During the PACU period, mean visual analogue scale values were significantly lower in groups 1 and 2 compared to group 3 (P < 0.05). During the postoperative period, morphine consumption was 3.03 ± 2.54, 2.7 ± 2.8, and 5.56 ± 3.12 mg for each group, respectively (P < 0.05). As a side effect, bleeding was observed in groups 1 and 3, nausea and vomiting in all groups...

Study of the BPP7a peptide and its β-cyclodextrin complex: physicochemical characterization and complete sequence specific NMR assignments

Lula,Ivana; Sousa,Frederico B. de; Denadai,Ângelo M. L; Ianzer,Danielle; Camargo,Antônio C. M. de; Santos,Robson A. S; Sinisterra,Rubén D
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2011 EN
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The BPP7a heptapeptide, p-Glu¹Asp²Gly³Pro4Ile5Pro6Pro7, forms an association complex with β-cyclodextrin in a 1:1 molar ratio. The peptide and its complex were characterized by circular dichroism (CD) and isothermal titration calorimetry (ITC), which showed a very weak interaction between the β-cyclodextrin and the peptide. Assignments of all hydrogen resonances of the peptide alone and as a complex were made using ¹H nuclear magnetic resonance (NMR) experiments at 400 and 600 MHz. High resolution diffusion ordered spectroscopy (HR-DOSY) experiments were carried out to establish the self-aggregation state of BPP7a. It was also shown that the β-cyclodextrin breaks the molecular clusters leading to complex formation. In addition, the anti-hypertensive activity of the BPP7a/β-cyclodextrin complex was evaluated in spontaneous hypertensive rats (SHR), showing increased activity compared to that of pure BPP7a.

Synthesis of C6A-to-C6A and C3A-to-C3A diamide linked γ-cyclodextrin dimers; Synthesis of C6A-to-C6A and C3A-to-C3A diamide linked gamma-cyclodextrin dimers

Pham, D.T.; Ngo, H.; Lincoln, S.; May, B.; Easton, C.
Fonte: Pergamon-Elsevier Science Ltd Publicador: Pergamon-Elsevier Science Ltd
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
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The syntheses of three new diamide-linked γ-cyclodextrin dimers joined by substitution at either a glucopyranose C6A or C3A carbon are reported. The syntheses involve the reaction of either C6A or C3A amino-substituted γ-cyclodextrin with bis(4-nitrophenyl)succinate to form succinamide linked γ-cyclodextrin dimers or reaction of C6A azide-substituted γ-cyclodextrin with carbon dioxide to form a urea linked γ-cyclodextrin dimer.; Duc-Truc Phama, Huy Tien Ngo, Stephen F. Lincoln, Bruce L. May and Christopher J. Easton

Beta-cyclodextrin modification and host-guest complexation.

Pham, Duc-Truc
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2008
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A series of five linked β-cyclodextrin (βCD) dimers N,N-bis(6 [superscript]A-deoxy-6[superscript]A-β-cyclodextrinyl)-succinamide, 66βCD₂su, N-((2[superscript]A S,3 [superscript]A S)-3 [superscript]A-deoxy-3 [superscript]A-β-cyclodextrinyl)-N’-(6 [superscript]A-deoxy-6 [superscript]A -β-cyclodextrinyl)-urea, 36βCD₂su, N,N-bis((2 [superscript]A S,3 [superscript]A S)-3 [superscript]A -deoxy-3 [superscript]A-β-cyclodextrinyl)-succinamide, 33βCD₂su, N,N-bis(6[superscript]A-deoxy-6[superscript]A-β-cyclodextrinyl)-urea, 66βCD₂ur, and N-((2 [superscript]A S,3 [superscript]A S)-3 [superscript]A-deoxy-3 [superscript]A-β-cyclodextrinyl)-N’-(6 [superscript]A -deoxy-6 [superscript]A -β-cyclodextrinyl)urea, 36βCD₂ur, has been prepared. The complexation of 6-(4’-(toluidinyl)naphthalene-2-sulphonate, TNS⁻, by βCD and the five linked βCD dimers was characterized by UV, fluorescence and 2D ¹H ROESY NMR spectroscopy. In aqueous phosphate buffer at pH 7.0, I = 0.10 mol dm⁻³ and 298.2 K, TNS⁻ forms host-guest complexes with βCD of stoichiometry βCD.TNS⁻ (K₁ = 3020 and 3320 dm³ mol⁻¹) and βCD₂.TNS⁻ (K₂ = 57 and 11 dm³ mol⁻¹) where the first and second values were determined in UV and fluorescence studies...

Supramolecular chemistry of beta- and gamma- cyclodextrin dimers.

Ngo, Huy Tien
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2010
Relevância na Pesquisa
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Native and modified cyclodextrins (CDs) act as robust hosts for a variety of guest species in water, and therefore are at the centre of supramolecular chemistry. Covalently linked CD dimers provide many advantages over native CDs in complexation of guest species in terms of their stability, selectivity or flexibility. The studies underpinning this thesis are based on the β-cyclodextrin dimers, N,N’-bis((2AS,3AS)-3A-deoxy-β-cyclodextrin-3A-yl) succinamide, 33βCD₂suc, and N,N′-bis(6A-deoxy-B-cyclodextrin-6A-yl) succinamide, 66βCD₂suc, and the γ-cyclodextrin dimers, N,N′-bis((2AS,3AS)-3A-deoxy-γ-cyclodextrin-3A-yl) succinamide, 33γCD2suc, and N,N′’-bis(6A-deoxy-γ-cyclodextrin-6A-yl) succinamide, 66γCD2suc, in which the two βCD or γCD cavities are joined together through either the C₃A or C₆A carbons of altropyranose or glucopyranose units, respectively. Often in supramolecular systems, several competing equilibria exist, as exemplified by host–guest complexation and guest aggregation. The complexation of dimerising cationic pyronines B and Y, PB⁺ and PY⁺, by βCD and the βCD dimers, 33βC₂suc and 66βCD₂suc, has been studied by UV–vis, fluorescence and ¹H NMR spectroscopy. The complexation constants for the 1:1 host–guest complexes are reported as are the dimerisation constants for PB⁺ and PY⁺. The modes of complexation...

The oligosaccharide α-cyclodextrin has modest effects to slow gastric emptying and modify the glycaemic response to sucrose in healthy older adults; The oligosaccharide alpha-cyclodextrin has modest effects to slow gastric emptying and modify the glycaemic response to sucrose in healthy older adults

Gentilcore, D.; Vanis, L.; Teng, J.; Wishart, J.; Buckley, J.; Rayner, C.; Horowitz, M.; Jones, K.
Fonte: C A B I Publishing Publicador: C A B I Publishing
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
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In healthy older subjects, the glycaemic response to carbohydrate-containing meals is dependent on gastric emptying and intestinal absorption; when the latter is slowed, the magnitude of the rise in glucose is attenuated. The oligosaccharide α-cyclodextrin has been reported to diminish the glycaemic response to starch in young adults; this effect has been attributed to the inhibition of pancreatic amylase. We examined the effects of α-cyclodextrin on gastric emptying of, and the glycaemic and insulinaemic responses to, oral sucrose in healthy older subjects; as sucrose is hydrolysed by intestinal disaccharides, any effect(s) of α-cyclodextrin would not be attributable to amylase inhibition. A total of ten subjects (seven males and three females, age 68–76 years) were studied on 2 d. Gastric emptying, blood glucose and serum insulin were measured after ingestion of a 300 ml drink containing 100 g sucrose, labelled with 99mTc-sulphur colloid, with or without 10 g α-cyclodextrin. Gastric emptying was slowed slightly by α-cyclodextrin; this effect was evident between 135 and 195 min and was associated with a slight increase (P < 0·05) in distal stomach retention. After α-cyclodextrin, blood glucose was slightly less (P < 0·05) at 60 min...

Herstellung und Charakterisierung eines b-Cyclodextrin / Kamillen-CO2-Extrakt-Komplexes als Wirkkomponente einer halbfesten Arzneiform; Preparation and characterisation of a camomile ointment containing a supercritical carbon dioxide camomile extract/b-cyclodextrin inclusion complex

Waleczek, Katharina Joanna
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
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Das Ziel dieser Arbeit ist die Entwicklung einer Kamillensalbe, welche eine feste Einschlussverbindung aus den Bestandteilen eines Kamillen-CO2-Extraktes in beta-Cyclodextrin enthält, um die Stabilität des Extraktes zu verbessern und den intensiven Kamillengeruch der Salbe zu reduzieren. Um die molekulare Zusammensetzung eines b-Cyclodextrin-Komplexes mit reinen Kamillenbestandteilen oder als Bestandteil des ätherischen Kamillenöls zu untersuchen, werden Phasen-Löslichkeits-Diagramme erstellt. Es resultiert ein Bs-Typ mit einer Stabilitätskonstante von 273 M-1 für reines (-)-a-Bisabolol und 304 M-1 für (-)-a-Bisabolol als Bestandteil des ätherischen Öls. Die Komplexe werden nach der Knetmethode hergestellte, wobei Konsistenz und Aussehen entsprechend dem Verhältnis von CO2-Extrakt zu b-Cyclodextrin variieren. Komplexe aus einem Teil CO2-Extrakt und 2 bis 5 Teilen b-Cyclodextrin führen zu pastösen Produkten, wohingegen aus 7 bis 10 Teilen b-Cyclodextrin und einem Teil CO2-Extrakt stabile Komplexe in Form von frei fließenden Pulvern resultieren. Die Wiederfindungsrate von b-Farnesen und (-)-a-Bisabolol in den Komplexen beträgt 90 - 99 Cis- und trans-En-In-Dicycloether (EID, syn. Spiroether) sind weniger stabil; unabhängig von der Komplexzusammensetzung werden 3 - 40 der Gastmoleküle beim Waschen mit n-Hexan entfernt. Der Stabilitätstest der Komplexe und der daraus hergestellten Salbe über 3 Monate zeigt...

Influence of beta-cyclodextrin on the properties of norfloxacin form A

Chierentin, Lucas; Garnero, Claudia; Chattah, Ana Karina; Delvadia, Poonam; Karnes, Thomas; Longhi, Marcela Raquel; Salgado, Herida Regina Nunes
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 683-691
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Processo FAPESP: 2010/13335-2; Cyclodextrins are able to form host-guest complexes with hydrophobic molecules to result in the formation of inclusion complexes. The complex formation between norfloxacin form A and beta-cyclodextrin was studied by exploring its structure affinity relationship in an aqueous solution and in the solid state. Kneading, freeze-drying, and physical mixture methods were employed to prepare solid complexes of norfloxacin and beta-cyclodextrin. The solubility of norfloxacin significantly increased upon complexation with beta-cyclodextrin as demonstrated by a solubility isotherm of the AL type along with the results of an intrinsic dissolution study. The complexes were also characterized in the solid stated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffractometry, scanning electron microscopy (SEM), and solid-state nuclear magnetic resonance (ssNMR) spectrometry. The thermal analysis showed that the thermal stability of the drug is enhanced in the presence of beta-cyclodextrin. Finally...

Diamide linked γ-cyclodextrin dimers as molecular-scale delivery systems for the medicinal pigment curcumin to prostate cancer cells; Diamide linked gamma-cyclodextrin dimers as molecular-scale delivery systems for the medicinal pigment curcumin to prostate cancer cells

Harada, T.; Giorgio, L.; Harris, T.; Pham, D.T.; Ngo, H.; Need, E.; Coventry, B.; Lincoln, S.; Easton, C.; Buchanan, G.; Kee, T.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
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Diamide linked γ-cyclodextrin (γ-CD) dimers are proposed as molecular-scale delivery agents for the anticancer agent curcumin. N,N'-Bis(6(A)-deoxy-γ-cyclodextrin-6(A)-yl)succinamide (66γCD2su) and N,N'-bis(6(A)-deoxy-γ-cyclodextrin-6(A)-yl)urea (66γCD2ur) markedly suppress the degradation of curcumin by forming a strong 1:1 cooperative binding complexes. The results presented in this study describe the potential efficacy of 66γCD2su and 66γCD2ur for intracellular curcumin delivery to cancer cells. Cellular viability assays demonstrated a dose-dependent antiproliferative effect of curcumin in human prostate cancer (PC-3) cells that was preserved by the curcumin-66γCD2su complex. In contrast, delivery of curcumin by 66γCD2ur significantly delayed the antiproliferative effect. We observed similar patterns of gene regulation in PC-3 cells for curcumin complexed with either 66γCD2su or 66γCD2ur in comparison to curcumin alone, although curcumin delivered by either 66γCD2su or 66γCD2ur induces a slightly higher up-regulation of heme oxygenase-1. Highlighting their nontoxic nature, neither 66γCD2su nor 66γCD2ur carriers alone had any measurable effect on cell proliferation or candidate gene expression in PC-3 cells. Finally...

Dimerisation and complexation of 6-(4'-t-butylphenylamino)naphthalene-2-sulphonate by β-cyclodextrin and linked β-cyclodextrin dimers; Dimerisation and complexation of 6-(4'-t-butylphenylamino)naphthalene-2-sulphonate by beta-cyclodextrin and linked beta-cyclodextrin dimers

Pham, D.T.; Clements, P.; Easton, C.; Papageorgiou, J.; Lincoln, S.; May, B.
Fonte: Gordon Breach Sci Publ Ltd Publicador: Gordon Breach Sci Publ Ltd
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
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37.39%
This study shows that stereochemical factors largely determine the extent to which 6-(4′-t-butylphenylamino)-naphthalene-2-sulphonate, BNS− and its dimer, (BNS− )2, are complexed by β-cyclodextrin, βCD, and a range of linked βCD dimers. Fluorescence and 1H NMR studies, respectively, show that BNS− and (BNS− )2 form host–guest complexes with βCD of the stoichiometry βCD.BNS− (10− 4 K 1 = 4.67 dm3 mol− 1) and βCD.BNS2 2 − (10− 2 K 2′ = 2.31 dm3 mol− 1), where the complexation constant K 1 = [βCD.BNS− ]/([βCD][BNS− ]) and K 2′ = [βCD. (BNS− )2]/([βCD.BNS− ][BNS− ]) in aqueous phosphate buffer at pH 7.0, I = 0.10 mol dm3 at 298.2 K. (The dimerisation of BNS− is characterised by 10− 2 K d = 2.65 dm3 mol− 1.) For N,N-bis((2AS,3AS)-3A-deoxy-3A-β-cyclodextrin)succinamide, 33βCD2su, N-((2AS,3AS)-3A-deoxy-3A-β-cyclodextrin)-N′-(6A-deoxy-6A-β-cyclodextrin)urea, 36βCD2su, N,N-bis(6A-deoxy-6A-β-cyclodextrin)succinamide, 66βCD2su, N-((2AS,3AS)-3A-deoxy-3A-β-cyclodextrin)-N′-(6A-deoxy-6A-β-cyclodextrin)urea, 36βCD2ur, and N,N-bis(6A-deoxy-6A-β-cyclodextrin)urea, 66βCD2ur, the analogous 10− 4 K 1 = 11.0, 101, 330, 29.6 and 435 dm3 mol− 1 and 10− 2 K 2′ = 2.56, 2.31, 2.59...

Cyclodextrin and modified cyclodextrin complexes of E -4- tert -butylphenyl-4-oxyazobenzene: UV-visible, 1 H NMR and ab initio studies

May, Bruce L; Gausia, K; Clements, Philip; Buntine, Mark; Brittain, David; Lincoln, Stephen F; Easton, Christopher
Fonte: Royal Society of Chemistry Publicador: Royal Society of Chemistry
Tipo: Artigo de Revista Científica
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α-Cyclodextrin, β-cyclodextrin, N-(6A-deoxy-α- cyclodextrin-6A-yl)-N′-(6A-deoxy-β- cyclodextrin-6A-yl)urea and N,N-bis(6A-deoxy-β- cyclodextrin-6A-yl)urea (αCD, βCD, l and 2) form inclusion complexes with E-4-tert-butylphenyl-4′-oxyazobenzene,

POLÍMEROS DE CICLODEXTRINA: CARACTERÍSTICAS, FORMAÇÃO DE COMPLEXOS DE INCLUSÃO E APLICAÇÕES INDUSTRIAIS; CYCLODEXTRIN POLYMERS: CHARACTERISTICS, INCLUSION COMPLEX FORMATION AND INDUSTRIAL APPLICATIONS

DRUNKLER, DEISY ALESSANDRA; Universidade Federal de Santa Catarina; FETT, ROSEANE; Universidade Federal de Santa Catarina; LUIZ, MARILDE T. BORDIGNON; Universidade Federal de Santa Catarina
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 01/04/2009 POR
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Apresenta revisão de literatura sobre características e aplicações da ciclodextrina. Discute estudos acerca de sua utilização como agente encapsulante de flavor, sua aplicação nas áreas de alimentos, farmacêutica e química, fornecendo dados a respeito de sua toxicidade.; It presents a literature review about features and application of cyclodextrin. It discusses studies related to cyclodextrin utilization as flavor-trap as well as its role in the food technology, medicine, and chemistry, bringing up data to the characteristics of toxicity.