Consulta: subjectFacets:"Cyclodextrins"
Registros recuperados: 5
Data/hora: 09/06/2024 18:17:30

A new low molecular mass alkaline cyclodextrin glucanotransferase from Amphibacillus sp. NRC-WN isolated from an Egyptian soda lake
Provedor de dados: 69
Autores: Al-Sharawi,Samar Z.R.; Ibrahim,Abdelnasser S.S.; El-Shatoury,Einas H; Gebreel,Hassan M; Eldiwany,Ahmad.
Background: Cyclodextrin glucanotransferase (CGTase) is one of the most industrially important enzymes used in the commercial production of cyclodextrins (CDs). Alkaliphilic bacteria have attracted much interest in the last few decades because of their ability to produce extracellular enzymes that are active and stable at high pH values. Here, we report the isolation of a new CGTase from alkaliphilic bacteria collected from Egyptian soda lakes and describe the purification and biochemical characterization of this CGTase. Results: Screening for CGTase-producing alkaliphilic bacteria from sediment and water samples collected from Egyptian soda lakes located in the Wadi Natrun valley resulted in the isolation of a potent CGTase-producing alkaliphilic...
Tipo: Journal article
Palavras-chave: Amphibacillus sp; Cyclodextrin glycosyltransferase; Cyclodextrins; Wadi Natrun soda lakes.
Ano: 2013
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582013000600003

Cyclodextrin glucanotransferase immobilization onto functionalized magnetic double mesoporous core-shell silica nanospheres
Provedor de dados: 69
Autores: Ibrahim,Abdelnasser S.S.; Al-Salamah,Ali A; El-Toni,Ahmed Mohamed; El-Tayeb,Mohamed A; Elbadawi,Yahya B.
Background Cyclodextrin glucanotransferase (CGTase) from Amphibacillus sp. NPST-10 was covalently immobilized onto amino-functionalized magnetic double mesoporous core-shell silica nanospheres (mag@d-SiO2@m-SiO2-NH2), and the properties of the immobilized enzyme were investigated. The synthesis process of the nanospheres included preparing core magnetic magnetite (Fe3O4) nanoparticles, coating the Fe3O4 with a dense silica layer, followed by further coating with functionalized or non-functionalized mesoporous silica shell. The structure of the synthesized nanospheres was characterized using TEM, XRD, and FT-IR analyses. CGTase was immobilized onto the functionalized and non-functionalized nanospheres by covalent attachment and physical adsorption. Results...
Tipo: Journal article
Palavras-chave: Amphibacillus sp; Cyclodextrin glucanotransferase; Cyclodextrins; Double mesoporous core-shell silica nanospheres; Immobilization.
Ano: 2014
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582014000200001

Colorimetric determination of alpha and beta-cyclodextrins and studies on optimization of CGTase production from B. firmus using factorial designs
Provedor de dados: 52
Autores: Higuti,Ilma Hiroko; Silva,Priscila Anunciação da; Papp,Juliana; Okiyama,Vivian Mayumi de Eiróz; Andrade,Edicléia Alves de; Marcondes,Aluizio de Abreu; Nascimento,Aguinaldo José do.
Cyclodextrin glycosyltransferase (EC 2.4.1.19, CGTase) production from B. firmus, isolated from soil of Curitiba, PR, was optimized in shake flask using an experimental design approach. The CGTase was produced when the carbon source was starch and beta-CD, but when simple sugars such as glucose, galactose, lactose, sucrose, and maltose were used, there was no enzyme production. CGTase production was the same with either organic nitrogen or inorganic nitrogen source. CGTase activity decreased 2-fold when incubation temperature was increased from 28 to 37 ° C, and decreased 2.1- fold when the initial pH was lowered from 10.3 to 7.4. The colorimetric determinations of alpha - and beta -CD were analyzed as a non-linear relationship and the equilibrium constant...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cyclodextrin glycosyltransferase; Bacillus firmus; Cyclodextrins.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132004000600001

Cyclodextrins and ternary complexes: technology to improve solubility of poorly soluble drugs
Provedor de dados: 60
Autores: Miranda,Janisse Crestani de; Martins,Tércio Elyan Azevedo; Veiga,Francisco; Ferraz,Humberto Gomes.
Cyclodextrins (CDs) are cyclic oligosaccharides composed of D-glucopyranoside units linked by glycosidic bonds. Their main property is the ability to modify the physicochemical and biological characteristics of low-soluble drugs through the formation of drug:CD inclusion complexes. Inclusion complexation requires that host molecules fit completely or partially within the CD cavity. This adjustment is directly related to the physicochemical properties of the guest and host molecules, easy accommodation of guest molecules within the CD cavity, stoichiometry, therapeutic dose, and toxicity. However, dosage forms may achieve a high volume, depending on the amount of CD required. Thus, it is necessary to increase solubilization efficiency in order to use...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cyclodextrins; Ternary complexes; Drugs/complexation; Water-soluble polymers/use; Drugs/solubility; Inclusion complexe.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502011000400003

Complexation and enhancement of temozolomide solubility with cyclodextrins
Provedor de dados: 60
Autores: Gürten,Berna; Yenigül,Elçin; Sezer,Ali Demir; Malta,Seyda.
ABSTRACT Temozolomide is a poorly soluble anti-cancer drug used in the treatment of some brain cancers. Following literature reports about the enhancement of solubility and stability for these kinds of drugs upon complexation with cyclodextrins, we aimed to form an inclusion complex between temozolomide and the different types of cyclodextrins (CDs) to enhance its solubility. In this study, three different cyclodextrins (β -CD, hydroxyl-β-CD and γ-CD) were used, and changes in solubility was measured by UV-Vis Spectroscopy and HPLC. Morphological changes upon complexation were shown by the Scanning Electron Microscope (SEM), and weight loss profiles with respect to temperatures which were unique to the compounds were shown by Thermogravimetric Analysis....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Temozolomide/solubility/complexation; Cyclodextrins; Chromatography; Calorimetry.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502018000200606