- Sweet surfactants: Packing parameter-invariant amphiphiles as emulsifiers and capping agents for morphology control of inorganic particles
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Surfactants are not only pivotal constituents in any biological organism in the form of phospholipids, they are also essential for numerous applications benefiting from a large, internal surface, such as in detergents, for emulsification purposes, phase transfer catalysis or even nanoparticle stabilization. A particularly interesting, green class of surfactants contains glycoside head groups. Considering the variability of glycosides, a large number of surfactant isomers become accessible. According to established models in surfactant science such as the packing parameter or the hydrophilic lipophilic balance (HLB), they do not differ from each other and should, thus, have similar properties. Here, we present the preparation of a systematic set of glycoside surfactants and in particular isomers. We investigate to which extent they differ in several key features such as critical aggregation concentration, thermodynamic parameters, etc. Analytical methods like isothermal titration calorimetry (ITC), tensiometry, dynamic light scattering (DLS), small angle-X-ray scattering (SAXS), transmission electron microscopy (TEM) and others were applied. It was found that glycosurfactant isomers vary in their emulsification properties by up to two orders of magnitude. Finally, we have investigated the role of the surfactants in a microemulsion-based technique for the generation of zinc oxide (ZnO) nanoparticles. We found that the choice of the carbohydrate head has a marked effect on the shape of the formed inorganic nanocrystals.
- Voggel, Michael,Meinusch, Rebecca M.,Siewert, Vanessa,Kunkel, Marius,Wittmann, Valentin,Polarz, Sebastian
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p. 7214 - 7227
(2018/09/26)
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- Synthesis and Properties of Alkyl β-d-Galactopyranoside
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A series of alkyl β-d-galactopyranosides were prepared by the trichloroacetimidate method with d-galactose and alcohols with different chain lengths as raw materials. Their solubility, surface tension, emulsification, foaming, wettability, thermotropic liquid crystalline properties, and thermal stability were investigated. Alkyl β-d-galactopyranosides are soluble in water and ethanol, and the solubility decreases with increasing alkyl chain length. Decyl β-d-galactopyranoside was insoluble in water, but soluble in ethanol. Dissolution of alkyl β-d-galactopyranoside in water is an endothermic process with dissolution enthalpies greater than zero. Nonyl β-d-galactopyranoside had an excellent emulsifying?property, better foaming ability and the best foam stability. The CMC values of alkyl β-d-galactopyranosides decrease with increasing of alkyl chain length. Alkyl β-d-galactopyranosides are thermally stable up to 270?°C. Alkyl β-d-galactopyranosides show the distinctive optical texture of a thermotropic liquid crystal smectic A type phase. Decyl β-d-galactopyranoside showed the strongest wettability.
- Chen, Guoyong,Li, Zhencao,Chen, Langqiu,Ji, Shanwei,Shen, Wangzhen
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p. 1095 - 1105
(2016/10/18)
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- Synthesis of glycotriazololipids and observations on their self-assembly properties
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Abstract Various carbohydrate-anchored triazole-linked lipids prepared by solvent-free mechanochemical azide-alkyne click reaction, on analysis by TEM, have been found to spontaneously self-assemble in solvents leading to structures of interesting physicochemical attributes. Interestingly, analogous compounds based on different sugars (e.g., d-glucose, and d-galactose, as also d-lactose) assemble in patterns distinctly different from each other thus reiterating the fact that the structure of the sugar as well as that of the lipid are important factors that determine the size and shape of the supramolecular assembly formed. Besides, the molecular self-assembly was also found to be solvent-as well as temperature-dependent.
- Tyagi, Mohit,Kartha, K.P. Ravindranathan
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supporting information
p. 85 - 92
(2015/06/30)
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- Chemoenzymatic synthesis of β-D-glucosides using cellobiose phosphorylase from Clostridium thermocellum
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Abstract Over the past decade, disaccharide phosphorylases have been successfully applied for the synthesis of numerous α-glucosides. In contrast, much less research has been done with respect to the production of β-glucosides. Although cellobiose phosphorylase was already successfully used for the synthesis of various disaccharides and branched trisaccharides, its glycosylation potential towards small organic compounds has not been explored to date. Unfortunately, disaccharide phosphorylases typically have a very low affinity for non-carbohydrate acceptors, which urges the addition of solvents. The ionic liquid AMMOENGTM 101 and ethyl acetate were identified as the most promising solvents, allowing the synthesis of various β-glucosides. Next to hexyl, heptyl, octyl, nonyl, decyl and undecyl β-D-glucopyranosides, also the formation of vanillyl 4-O-β-D-glucopyranoside, 2-phenylethyl β-D-glucopyranoside, β-citronellyl β-D-glucopyranoside and 1-O-β-D-glucopyranosyl hydroquinone was confirmed by nuclear magnetic resonance spectroscopy and mass spectrometry. Moreover, the stability of cellobiose phosphorylase could be drastically improved by creating cross-linked enzyme aggregates, while the efficiency of the biocatalyst for the synthesis of octyl β-D-glucopyranoside was doubled by imprinting with octanol. The usefulness of the latter system was illustrated by performing three consecutive batch conversions with octanol imprinted cross-linked enzyme aggregates, yielding roughly 2 g of octyl β-D-glucopyranoside.
- De Winter, Karel,Van Renterghem, Lisa,Wuyts, Kathleen,Pelantová, Helena,K?en, Vladimír,Soetaert, Wim,Desmet, Tom
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p. 1961 - 1969
(2015/06/02)
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- Biphasic catalysis with disaccharide phosphorylases: Chemoenzymatic synthesis of α- D -glucosides using sucrose phosphorylase
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Thanks to its broad acceptor specificity, sucrose phosphorylase (SP) has been exploited for the transfer of glucose to a wide variety of acceptor molecules. Unfortunately, the low affinity (Km > 1 M) of SP towards these acceptors typically urges the addition of cosolvents, which often either fail to dissolve sufficient substrate or progressively give rise to enzyme inhibition and denaturation. In this work, a buffer/ethyl acetate ratio of 5:3 was identified to be the optimal solvent system, allowing the use of SP in biphasic systems. Careful optimization of the reaction conditions enabled the synthesis of a range of α-d-glucosides, such as cinnamyl α-d-glucopyranoside, geranyl α-d-glucopyranoside, 2-O-α-d-glucopyranosyl pyrogallol, and series of alkyl gallyl 4-O-α-d-glucopyranosides. The usefulness of biphasic catalysis was further illustrated by comparing the glucosylation of pyrogallol in a cosolvent and biphasic reaction system. The acceptor yield for the former reached only 17.4%, whereas roughly 60% of the initial pyrogallol was converted when using biphasic catalysis.
- De Winter, Karel,Desmet, Tom,Devlamynck, Tim,Van Renterghem, Lisa,Verhaeghe, Tom,Pelantova, Helena,Kren, Vladimir,Soetaert, Wim
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p. 781 - 787
(2014/07/08)
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- Preparation of two glycoside hydrolases for use in micro-aqueous media
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Enzymatic synthesis of alkyl glycosides using glycoside hydrolases is well studied, but has yet to reach industrial scale, primarily due to limited yields. Reduced water content should increase yields by limiting the unwanted hydrolytic side reaction. However, previous studies have shown that a reduction in water content surprisingly favors hydrolysis over transglycosylation. In addition, glycoside hydrolases normally require a high degree of hydration to function efficiently. This study compares six enzyme preparation methods to improve resilience and activity of two glycoside hydrolases from Thermotoga neapolitana (TnBgl3B and TnBgl1A) in micro-aqueous hexanol. Indeed, when adsorbed onto Accurel MP-1000 both enzymes increasingly favored transglycosylation over hydrolysis at low hydration, in contrast to freeze-dried or untreated enzyme. Additionally, they displayed 17-70× higher reaction rates compared to freeze-dried enzyme at low water activity, while displaying comparable or lower activity for fully hydrated systems. These results provide valuable information for use of enzymes under micro-aqueous conditions and build toward utilizing the full synthetic potential of glycoside hydrolases.
- Lundemo, Pontus,Karlsson, Eva Nordberg,Adlercreutz, Patrick
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- Ionic liquids as cosolvents for glycosylation by sucrose phosphorylase: Balancing acceptor solubility and enzyme stability
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Over the past decade, disaccharide phosphorylases have received increasing attention as promising biocatalysts for glycoside synthesis. Unfortunately, these enzymes typically have a very low affinity for non-carbohydrate acceptors, which urges the addition of cosolvents to increase the dissolved concentration of these acceptors. However, commonly applied solvents such as methanol and dimethyl sulfoxide (DMSO) are not compatible with many intended applications of carbohydrate-derived products. In this work, the solubility of a wide range of relevant acceptors was assessed in the presence of ionic liquids (ILs) as alternative and 'green' solvents. The IL AMMOENG 101 was found to be the most effective cosolvent for compounds as diverse as medium- and long-chain alcohols, flavonoids, alkaloids, phenolics and terpenes. Moreover, this IL was shown to be less deleterious to the stability and activity of sucrose phosphorylase than the commonly used dimethyl sulfoxide. To demonstrate the usefulness of this solvent system, a process for the resveratrol glycosylation was established in a buffer containing 20% AMMOENG 101, 1 M sucrose and saturated amounts of the acceptor. A single regioisomer 3-O-α-d-glucopyranosyl-(E)-resveratrol was obtained as proven by NMR spectroscopy.
- De Winter, Karel,Verlinden, Kristien,Kren, Vladimir,Weignerova, Lenka,Soetaert, Wim,Desmet, Tom
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p. 1949 - 1955
(2013/09/24)
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- Significantly improved equilibrium yield of long-chain alkyl glucosides via reverse hydrolysis in a water-poor system using cross-linked almond meal as a cheap and robust biocatalyst
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An array of ten β-D-glucopyranosides with varied alkyl chain lengths were enzymatically synthesized. It was found that for longer alkyl chains a lower initial rate and final yield of glucoside was obtained except for methyl glucoside because of the severe toxicity of methanol to the enzyme. From a thermodynamics point of view, the equilibrium constant and Gibbs free energy variation of the glucoside syntheses were systematically investigated. To improve the final yields of the glucosides containing long alkyl chains the equilibrium of the enzymatic glucoside synthesis was altered. The equilibrium yield of decyl β-D-glucoside increased from 1.9 to 6.1 when the water content was reduced from 10 to 5 (v/v) using tert-butanol as a cosolvent and 0.10 mol/L of glucose as a substrate. As for the other longer alkyl chain glucosides, heptyl β-D-glucoside was found to have significant surface activity as well.
- Wang, Qinqqin,Yu, Huilei,Zhao, Na,Li, Chunxiu,Shang, Yazhuo,Liu, Honglai,Xu, Jianhe
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p. 275 - 280
(2012/06/29)
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- Significantly Improved Equilibrium Yield of Long-Chain Alkyl Glucosides via Reverse Hydrolysis in a Water-Poor System Using Cross-Linked Almond Meal as a Cheap and Robust Biocatalyst
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An array of ten β-D-glucopyranosides with varied alkyl chain lengths were enzymatically synthesized. It was found that for longer alkyl chains a lower initial rate and final yield of glucoside was obtained except for methyl glucoside because of the severe toxicity of methanol to the enzyme. From a thermodynamics point of view, the equilibrium constant and Gibbs free energy variation of the glucoside syntheses were systematically investigated. To improve the final yields of the glucosides containing long alkyl chains the equilibrium of the enzymatic glucoside synthesis was altered. The equilibrium yield of decyl β-D-glucoside increased from 1.9% to 6.1% when the water content was reduced from 10% to 5% (v/v) using tert-butanol as a cosolvent and 0.10 mol/L of glucose as a substrate. As for the other longer alkyl chain glucosides, heptyl β-D-glucoside was found to have significant surface activity as well.
- Wang, Qinqqin,Yu, Huilei,Zhao, Na,Li, Chunxiu,Shang, Yazhuo,Liu, Honglai,Xu, Jianhe
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p. 275 - 280
(2016/04/10)
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- Transformation of cellulose into biodegradable alkyl glycosides by following two different chemical routes
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The transformation of cellulose into long-chain alkyl glycoside surfactants has been carried out following two different routes: (1) Direct transformation of cellulose to butyl-, hexyl-, octyl-, decyl- and dodecyl-α,β- glycosides in an ionic liquid media and Amberlyst-15Dry as catalysts, with mass yield of up to 82%; and (2) two steps reaction with transformation of cellulose into methyl glucosides, with a procedure described by Zhang et al., followed by transacetalation with 1-octanol and 1-decanol in the presence of Amberlyst-15Dry. A kinetic study for the direct transformation of cellulose using 1-octanol has shown that depolymerisation of cellulose continues during the Fischer glycosidation. Increasing the chain length of the alcohol decreases the global reaction rate owing to an increase in the lipophilicity of the alcohol that decreases its contact with the carbohydrates. Finally, several acid catalysts were tested and the best results were obtained with Amberlyst-15Dry.
- Villandier, Nicolas,Corma, Avelino
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experimental part
p. 508 - 513
(2012/03/08)
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- POLYMER STABILIZER
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A polymer stabilizer comprising the following alkoxy compound: the alkoxy compound: a compound obtained by alkoxylating at least one hydroxyl group contained in a compound of the following formula (1) containing one formyl group or carbonyl group and (n?1) hydroxyl groups in the molecule with an alkyl group having 1 to 12 carbon atoms: [in-line-formulae]CnH2nOn??(1)[/in-line-formulae] (wherein, n represents an integer of 3 or more).
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- Synthesis of alkyl and cycloalkyl α-D-mannopyranosides and derivatives thereof and their evaluation in the mycobacterial mannosyltransferase assay
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The synthesis of a series of alkyl (having from C6 to C20 aglycones), cyclohexyl, and cyclohexylalkyl α-Dmannopyranosides, 6-deoxygenated analogs, thioglycosides, and sulfones derived thereof, is reported. Here, under the in vitro assay conditions used, n
- Polakova, Monika,Belanova, Martina,Petrus, Ladislav,Mikusova, Katarina
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experimental part
p. 1339 - 1347
(2010/10/02)
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- One pot catalytic conversion of cellulose into biodegradable surfactants
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Cellulose has been directly converted into environmentally friendly alkyl glycoside surfactants in a one pot transformation. By working in ionic liquid media with Amberlyst 15Dry (A15) as catalyst and coupling the rate of cellulose hydrolysis and the rate of glycosidation of the monosaccharides formed with C4 to C8 alcohols, it was possible to obtain 82% mass yield of octyl-α,β-glucoside plus octyl-α,β-xyloside.
- Villandier, Nicolas,Corma, Avelino
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supporting information; scheme or table
p. 4408 - 4410
(2010/09/15)
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- A new method of synthesis of alkyl β-glycosides using sucrose as sugar donor
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Cellobiose phosphorylase from Clostridium thermocellum catalyzed the β-anomer-selective synthesis of alkyl glucosides from cellobiose. Synthesis of alkyl β-glucoside from inexpensive sucrose using cellobiose phosphorylase and sucrose phosphorylase from Pseudomonas saccharophilia was investigated. By combined use of these two phosphorylases, alkyl β-glucoside was anomer-selectively synthesized from sucrose and alkyl alcohol.
- Kino, Kuniki,Satake, Ryoko,Morimatsu, Takayuki,Kuratsu, Shoko,Shimizu, Yu,Sato, Masaru,Kirimura, Kohtaro
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p. 2415 - 2417
(2008/12/23)
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- Synthesis of n-alkyl glucosides by amyloglucosidase
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Amyloglucosidase from Rhizopus mold (3.2.1.3) has been employed for the synthesis of n-alkyl glucosides from alcohols of carbon chain lengths Cl to C18 by both shake flask and reflux methods. Glucoside yields obtained from the reflux method (5-44%) are better than those from the shake flask method (3-28%). While the shake flask method favoured glucosylation of medium chain length alcohols, the reflux method at pH 5.0, favoured glucosylation of all the chain lengths. n-Octyl-D-glucoside, n-octyl-maltoside and n-octyl-sucroside are also synthesized and optimum conditions for the synthesis of n-octyl-D-glucoside at both shake flask and reflux methods have been worked out.
- Vijayakumar, Giriyapura R.,George, Charles,Divakar, Soundar
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p. 314 - 319
(2008/02/09)
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- ANTI-ADHESIVE COMPOUNDS TO PREVENT AND TREAT BACTERIAL INFECTIONS
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The present invention provides compounds and compositions capable of inhibiting the attachment of Gram-negative bacteria on a host epithelium. Accordingly, said compounds and compositions can for example be used for the manufacture of a medicament to trea
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Page/Page column 11
(2008/06/13)
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- Novel reaction systems for the synthesis of O-glucosides by enzymatic reverse hydrolysis
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Our studies are presented to replace alcohols as solvents in reverse hydrolytic reactions catalyzed by immobilized β-glucosidase to synthesize O-substituted β-D-glucopyranosides in preparative-scale. We found that 1,2-diacetoxyethane is a suitable solvent and O-alkyl or aryl β-D-glucosides were synthesized in moderate yields (after isolation 12-19%). In these reactions proportion of glucose and glucosyl acceptor hydroxy compounds was 1:20. We suggest that 1,2-diacetoxyethane can be useful not only for alcohols but for other glucosyl donor compounds unsuitable for the role of solvent (e.g., phenols) in the synthesis of O-β-D-glucosides by reverse hydrolysis.
- Balogh, Teréz,Boross, László,Kosáry, Judit
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p. 679 - 682
(2007/10/03)
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- Chemoenzymatic synthesis of n-hexyl and O-β-D-xylopyranosyl-(1→6) -β-D-glucopyranosides
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Direct β-glucosidation between 1,6-octanediol (5) and D-glucose (3) using the immobilized β-glucosidase (EC 3.2.1.21) from almonds with the synthetic prepolymer ENTP-4000 gave a mono-β-glucoside (6) in 61.4% yield, which was converted into the n-hexyl β-D
- Kishida, Masashi,Nishiuchi, Miho,Kato, Keisuke,Akita, Hiroyuki
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p. 1105 - 1108
(2007/10/03)
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- Processes for producing saccharide derivatives using solid ultrastrong acid
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This invention provides glycoside polymers or glycosides which are useful as a material for functional foods, biodegradable fibers or medicaments, said glycoside polymers being produced efficiently by subjecting a compound of the formula (1): wherein R1is —OH, R2is —OH or —NHCOCH3, R3is —CH2OH, —COOH or —CH3, to a melt polymerization or a solution polymerization in the presence of a solid superacid, and said glycosides being produced by reacting the compound (1) with a saturated or unsaturated alcohol in the presence of a solid superacid.
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- Preparation of alkyl α- and β-D-glucopyranosides, thermotropic properties and X-ray analysis
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Monohydrates of heptyl to decyl α-D-glucopyranosides as obtained from product mixtures of the Fischer glucosylation were crystallized from water at the Krafft point. The results of the single-crystal X-ray analysis of anhydrous α anomers and their monohydrates provide for a better understanding of crystal formation and stability of their hydrates. The preparation of alkyl β-D-glucopyranosides-without concomitant formation of α anomers as by-products-has been described. The thermotropic properties have been investigated for the α compounds and their monohydrates, and for the β-D-glucopyranosides. Copyright (C) 1998 Elsevier Science Ltd.
- Adasch, Volker,Hoffmann, Bettina,Milius, Wolfgang,Platz, Gerhard,Voss, Gundula
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p. 177 - 187
(2007/10/03)
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- Synthesis of detergent O-glucosides by reverse hydrolysis in alcohol- water biphasic systems using α- and β-glucosidases
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The α- and β-glucosidases showed significant O-glycosylation activity with glucose as substrate and with different alcohols both as reaction partners and solvents in reverse hydrolytic processes. With native glucosidases upscaling resulted in low yields due to heterogeneity of reaction mixtures. Immobilization of the enzymes on a modified polyacrylamide-type bead support (Acrylex C-100) increased enzyme stability resulting in higher yields and permitted to perform glucosylations on a larger scale. From these experiments O-alkyl glucosides were isolated in moderate yields.
- Kosary, Judit,Stefanovits-Banyai,Boross
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p. 611 - 613
(2007/10/03)
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- Enzyme-catalysed synthesis of alkyl β-D-Glucosides in organic media
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The synthetic potential of Almond β-D-Glucosidase for the synthesis of alkyl glucosides was studied. The regio and stereoselectivity of the synthesis were analysed for the reverse hydrolysis and the transglucosylation methods in tert-butanol and acetonitrile media.
- Vic, Gabin,Thomas, Daniel
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p. 4567 - 4570
(2007/10/02)
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