- 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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- Glycosides and?amino acyl esters of?carbohydrates as?potent inhibitors of?angiotensin converting enzyme
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About 12 glycosides prepared through amyloglucosidase catalysis and 23 amino acyl esters of carbohydrates prepared through lipase catalysis in organic solvents showed angiotensin converting enzyme (ACE) inhibition activity. Both amino acyl esters of carbohydrates and glycosides exhibited IC50 values for ACE inhibition in the 0.5?mM to 15.7?mM range. Eugenyl-d-glucoside (IC50: 0.5 ± 0.04?mM), l-isoleucyl-d-glucose (IC50: 0.7 ± 0.067?mM), vanillyl-d-sorbitol (IC50: 0.8 ± 0.09?mM), l-histidyl-d-fructose (IC50: 0.9 ± 0.087?mM), l-tryptophanyl-d-fructose (IC50: 0.9 ± 0.092?mM), octyl-d-glucoside (IC50: 1.0 ± 0.093?mM), vanillyl-d-mannoside (IC50: 1.0 ± 0.089?mM), l-valyl-d-mannitol (IC50: 1.0 ± 0.092?mM) and l-phenylalanyl-d-glucose (IC50: 1.0 ± 0.089?mM) were the compounds, which showed the best ACE inhibitory activities.
- Lohith,Vijayakumar,Somashekar,Sivakumar,Divakar
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- Estrogenicity of octyl glucoside synthesized by direct glucosidation as non-endocrine disruptive surfactant
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The estrogenicity of octyl glucoside was studied with its preparation method using microporous zeolites. Its estrogenicity was estimated using E-assay method to confirm the possibility as nonendocrine disruptive surfactant. The octyl glucoside was synthesized from D-glucose with 1-octanol by direct glucosidation. The high conversion of D-glucose was obtained on H-FAU zeolite which has a mild acid strength. The conversion and yield were improved with increasing of acid site amount of the zeolite catalysts. The octyl glucopyranoside is more hydrophilic than nonylphenol and has a high wettability. The octyl glucosides represented extremely lower estrogenic cell proliferation compared with nonylphenol.
- Chung, Kyong-Hwan,Kim, Hangun,Park, Young-Kwon,Kim, Byung-Hoon,Kim, Jung-Sik,Jung, Sang-Chul
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- 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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- Micellar effect on the direct Fischer synthesis of alkyl glucosides
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This manuscript presents results from the investigation on the synthesis of alkyl glucosides by the novel, very efficient and environmentally friendly protocol of the Fischer-type synthesis from unprotected glucose and aliphatic alcohols. The use of the dual functionality catalysts (surfactant?+?acid catalyst) and micellar reaction system are the main novelty of described method. It has been found, that in developed method of synthesis the reaction of unprotected glucose with aliphatic alcohols carried out with significantly different route, than the normal (classical) route and leads to alkyl glucopyranoside derivatives with high yields. In progress analyses by DLS, HPLC and GC/MS confirm the general postulated pathway of developed method.
- Nowicki,Woch,Mo?cipan,Nowakowska-Bogdan
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- Polyvinyl trisulfonate ethylamine based solid acid catalyst for the efficient glycosylation of sugars under solvent free conditions
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Heterogeneous Bronsted solid acid catalysts have the potential to decrease the environmental impact related to chemical production. Herein, we have synthesized polyvinyl bound trisulfonate ethylamine chloride (PV-THEAC) and polyvinyl bound disulfonate ethylamine (PV-DSEA) as Bronsted solid acid catalysts which exhibited effective catalytic activity for acid catalyzed glycosylation reactions with sugar derivatives. In particular, 0.3 equiv. of the PV-THEAC catalyst was found to be the most efficient and a reusable catalyst for glycosylation reactions. A high density of the trisulfonic group (-OSO3H) contributed to the excellent catalytic activity during glycosylation. Moreover, glycosylation reactions with d-mannose, d-xylose and d-glucose have been studied with alcohol. Remarkable acceleration of the glycosylation reaction using a glycosyltrichloroacetimidate donor was obtained with the selective production of β-glycoside.
- Chaugule, Avinash A.,Jadhav, Amol R.,Kim, Hern
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p. 104715 - 104724
(2015/12/30)
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- Exploring the meaning of sugar configuration in a supramolecular environment: Comparison of six octyl glycoside micelles by ITC and NMR spectroscopy
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A series of octyl α- and β-glycosides of the manno- galacto- and gluco-series were synthesized and employed in formation of homo- and hetero-micelles in water. Critical micelle concentrations (cmc), thermodynamic quantities of demicellation and, to some extent, the hydrodynamic radii of glycomicelles were determined by isothermal titration calorimetry (ITC) and diffusion NMR studies. The goal of this work was to determine the significance of anomeric configuration as well as of epimerisation at the sugar ring for supramolecular features of the respective glycoside. A new projection of glycoside structures is proposed to facilitate interpretation of structure-property relationships in this regard. This journal is the Partner Organisations 2014.
- Schmidt-Lassen, J?rn,Lindhorst, Thisbe K.
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supporting information
p. 1218 - 1226
(2014/08/05)
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- Glycosylation mediated - BAIL in aqueous solution
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The use of Br?nsted acid ionic liquid (BAIL) as a catalyst for the activation of unreactive and unprotected glycosyl donors has been demonstrated for the first time in aqueous solution.
- Delacroix, Sébastien,Bonnet, Jean-Pierre,Courty, Matthieu,Postel, Denis,Van Nhien, Albert Nguyen
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- Protection-free synthesis of alkyl glycosides under hydrogenolytic conditions
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A convenient protection-free synthetic route for the preparation of alkyl glycosides has been developed. The alcoholysis of one-step preparable glycosyl donors, 4,6-dibenzyloxy-1,3,5-triazin-2-yl (DBT) glycosides, under hydrogenolytic conditions gave the corresponding glycosides in good yields without the addition of any acid promoters. The method could be successfully applied to the glycosylation of an acidlabile oligosaccharide.
- Ishihara, Masaki,Takagi, Yuka,Li, Gefei,Noguchi, Masato,Shoda, Shin-Ichiro
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supporting information
p. 1235 - 1237
(2013/10/22)
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- Straightforward glycosylation of alcohols and amino acids mediated by ionic liquid
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Green glycosylation of functionalized alcohols and α-amino acids, using an ionic liquid as a recyclable solvent, was performed in one step directly from the unprotected monosaccharide under scandium triflate or ferric chloride catalysis. Pure α- and β-glycosides could be obtained after specific enzymatic hydrolysis.
- Monasson, Olivier,Sizun-Thomé, Gwena?lle,Lubin-Germain, Nadège,Uziel, Jacques,Augé, Jacques
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scheme or table
p. 202 - 205
(2012/06/30)
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- Green glycosylation promoted by reusable biomass carbonaceous solid acid: An easy access to β-stereoselective terpene galactosides
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An efficient green protocol has been developed for the atom economic glycosylation of unprotected, unactivated glycosyl donors and glycosylation of glycosyl trichloroacetimidates with the aid of reusable eco-friendly biomass carbonaceous solid acid as catalyst. The Royal Society of Chemistry.
- Gorityala, Bala Kishan,Ma, Jimei,Pasunooti, Kalyan Kumar,Cai, Shuting,Liu, Xue-Wei
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supporting information; experimental part
p. 573 - 577
(2011/05/06)
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- Efficient glycosylation of unprotected sugars using sulfamic acid: A mild eco-friendly catalyst
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Sulfamic acid, a mild and environmentally benign catalyst has been successfully used in the Fischer glycosylation of unprotected sugars for the preparation alkyl glycosides. A diverse range of aliphatic alcohols have been used to prepare a series of alkyl glycosides in good to excellent yield.
- Guchhait, Goutam,Misra, Anup Kumar
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experimental part
p. 52 - 57
(2012/01/15)
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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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- Cellulose conversion into alkylglycosides in the ionic liquid 1-butyl-3-methylimidazolium chloride
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The conversion of cellulose into alkylglycosides is carried out in the ionic liquid 1-butyl-3-methylimidazolium chloride in the presence of an acidic catalyst. Primary alcohols like n-butanol and n-octanol were used as alkylating reagents. The acidic resin Amberlyst 15DRY proved to be the optimum heterogeneous catalyst: it catalyzes the hydrolysis of the β(1→4) links in the cellulose polymeric chain as well as the alkylation of the hydroxyl groups at the C1 position of the glucose intermediate. The cellulose was fully converted under mild conditions; in a reaction with n-butanol, the obtained yield of butylglucopyranoside isomers was 86%.
- Ignatyev, Igor A.,Mertens, Pascal G. N.,Van Doorslaer, Charlie,Binnemans, Koen,De Vos, Dirk E.
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scheme or table
p. 1790 - 1795
(2011/02/21)
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- Ionic liquid promoted atom economic glycosylation under Lewis acid catalysis
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Straightforward glycosylation of various alcohols with unprotected and non-activated monosaccharides were performed under scandium triflate catalysis. Rate and yield of glycosylation were highly improved when using 1-butyl-3-methylimidazolium trifluoromethanesulfonate as a green solvent. This ionic liquid was allowed to be recycled at least three times without loss of activity. The possibility of drastically reducing the amounts of catalyst (down to 1 mol%) and aglycone (down to 1 equiv) when performing the reaction in ionic liquid opens new perspectives in O-glycosylation, as a direct coupling between an aglycone and free sugars.
- Auge, Jacques,Sizun, Gwenaelle
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scheme or table
p. 1179 - 1183
(2010/05/02)
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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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- Evaluating the Baylis-Hillman reaction of cyclic enones using surfactants in water
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Conjugated cyclic enones react smoothly in water with a variety of aldehydes (Baylis-Hillman reaction) in the presence of surfactants above their critical micelle concentrations (CMC). Georg Thieme Verlag Stuttgart.
- Porzelle, Achim,Williams, Craig M.,Schwartz, Brett D.,Gentle, Ian R.
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p. 2923 - 2926
(2007/10/03)
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- Molecular recognition of carbohydrates with acyclic pyridine-based receptors
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The recognition capabilities of acyclic pyridine-based receptors toward monosaccharides were evaluated. Aminopyridine receptors based on the 2,4,6-trimethyl- or 2,4,6-triethylbenzene frame show high β vs α binding selectivity in the recognition of glucopyranosides. Amidopyridine receptors, which are sterically less hindered at nitrogen, display high efficiency and an inverse selectivity. The 2-aminopyridine group has been established as a highly effective recognition group in the binding of monosaccharides. The factors influencing the binding properties of receptors 1-15, which differ in the nature and number of binding and spacer subunits used as the buildings blocks, are discussed.
- Mazik, Monika,Radunz, Wolfgang,Boese, Roland
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p. 7448 - 7462
(2007/10/03)
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- Microwave-assisted synthesis of alkyl glycosides
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The reaction of sugars with alcohols and catalytic amounts of an acid in a high frequency field (2.45 GHz) leads to high yields of the corresponding alkyl glycosides. The ratio of the α/β-anomers is influenced by the reaction conditions and reaction controlling.
- Nuechter,Ondruschka,Lautenschlaeger
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p. 1277 - 1283
(2007/10/03)
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- A simple polar deacetylated caloporoside derivative is a positive modulator of the GABA(A) chloride channel complex in cortical mammalian neurones
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Synthesis of octyl-O-β-D-mannopyranoside, a caloporoside analogue was achieved by the activation of 2,3,4,6-tetra-O-benzyl-1-O-1',3'2'-dioxaphosphacy clohexane-α,β-D-mannopyranosyl-2-oxide with TMSOTf (Trimethyl silyl triflate) and subsequent debenzylation. At 100 μM the molecule significantly and reversibly increased the magnitude of GABA(A) currents evoked in cultured rat pyramidal neurones whilst concomitantly reducing the incidence of spontaneous synaptic activity. These results contradict earlier proposals that such molecules bind to the TBPS (tert-Butylbicyclophosphorothionate) site to block the chloride channel. (C) 2000 Elsevier Science Ltd. All rights reserved.
- Lees, George,Chazot, Paul L.,Vankayalapati, Hariprasad,Singh, Gurdial
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p. 1759 - 1761
(2007/10/03)
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- A new synthesis of O-glycosides from totally O-unprotected glycosyl donors
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O-Glycosidation of the totally O-unprotected aldoses (D-glucose, D-galactose and D-mannose) and D-fructose in THF or 1,4-dioxane using anhydrous FeCl3 as promoter afforded either aldofuranosides 1, 3, 4 in good overall yields or exclusively β-D-fructopyranosides 7. Conversely α-D-aldopyranosides 2, 5 and 6 were obtained respectively from D-glucose, D-mannose and N-acetyl-D-glucosamine when the reactions were performed in the presence of BF3.OEt2 under ultrasonication.
- Ferrieres, Vincent
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p. 2749 - 2752
(2007/10/02)
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