Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.21 (beta-glucosidase)
 3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chitosan (CH) was dissolved in aqueous solutions containing aspartic, glutamic, hydrochloric, lactic and citric acids to obtain different chitosan salts. Chitosan salts were collected from the solutions by spray-drying and the powders obtained were mixed with Sodium Diclofenac (SD), taken as a model anti-inflammatory drug. This study evaluated in vitro the influence of acid type on the release behaviour of SD from the physical mixture during gastrointestinal transit. The physical mixture of the chitosan salts with SD provided slower drug release than the pure drug both in acidic and alkaline pHs. In addition, the interaction with beta-glucosidase at pH 7.0 enhanced the release rate. Among the CH salts used, glutamic and aspartic salts provided the best control of release.
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PMID:Influence of different chitosan salts on the release of sodium diclofenac in colon-specific delivery. 1199 10

Removal of beta-glucosidase (BG) from cellulase is essential to the enzymatic production of cellobiose from cellulose because of the high reactivity of BG with cellobiose to form glucose. Chitosan is a reversibly soluble-insoluble polymer depending on pH, and it has an affinity with the other components, endo-beta-1,4-glucanase and cellobiohydrolase, or cellulase. The affinity precipitation technique using chitosan is an effective way to fractionate cellulase for the above purpose. Hydrolysis experiments of cellulose with the residual fractionated enzyme gave higher cellobiose contents in the soluble sugar products.
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PMID:Production of cellobiose by enzymatic hydrolysis: removal of beta-glucosidase from cellulase by affinity precipitation using chitosan. 1860 68

The influence of polyelectrolyte complexes composed of chitosan and pectin on the release behaviour of vancomycin has been investigated. Polyelectrolyte complexes between chitosan and pectin were prepared in various pH regions and at different molar ratios by mixing solutions of pectin and chitosan with the same ionic strength. The precipitates were collected by spray-drying and tablets were obtained with the different complexes and vancomycin. FT-IR spectra and TGA thermograms were analysed to study the degree of interactive strength between polyions. In vitro swelling, mucoadhesion and release tests were performed in order to investigate the chitosan/pectin complex ability in the delivery of vancomycin in the gastro-intestinal tract. The results confirmed the formation of polyelectrolyte complexes between pectin and chitosan at pH values in the vicinity of the pKa interval of the two polymers. Chitosan/pectin complexes showed a pH-sensitive swelling ability and drug release behaviour suggesting their possible use for colon-specific localization of vancomycin. Among the different complexes, chitosan/pectin complex prepared in molar ratio of 1:9 showed the highest mucoadhesive properties and a pH-dependent swelling sensitivity suitable for colon-delivery. Moreover, the particular composition of these complexes improved vancomycin availability at alkaline pH on the bases of an enzyme-dependent degradation as confirmed from release studies performed in presence of beta-glucosidase.
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PMID:Chitosan/pectin polyelectrolyte complexes: selection of suitable preparative conditions for colon-specific delivery of vancomycin. 1895 77

The aim of the study was to define in vitro and in vivo characteristics of chitosan/Kollicoat SR30D film-coated tablets of theophylline for colonic delivery. The tablet cores were coated to different film thicknesses with blends of Kollicoat SR30D and chitosan (2.5:1, 3.5:1, and 5:1, w/w). Swelling and drug release studies were carried out in simulated gastric fluid, simulated intestinal fluid and simulated colonic fluid, respectively. The mechanism of drug release was determined using the Korsmeyer-Peppas model. The in vivo degradation of the tablets was also studied in rats. The swelling behavior and drug release depended on the composition of the coating, as well as the ratio of Kollicoat SR30D to chitosan. The coating was susceptible to enzymatic action, and more accessible to bacterial enzymes than beta-glucosidase enzyme. The extent of swelling and digestion correlated with the amount of chitosan within the coating. The drug release data fit well into the Korsmeyer-Peppas equation, indicating that the drug release was controlled by polymer relaxation. The in vivo pharmacokinetic studies of the coated tablets showed delayed T(max), decreased C(max) and prolonged MRT. Chitosan/Kollicoat SR30D coated tablets could deliver the drug to the targeted site for local action.
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PMID:Studies of chitosan/Kollicoat SR 30D film-coated tablets for colonic drug delivery. 1945 27