- Hollow ni-p amorphous alloy nanospheres: An efficient catalyst for sugars hydrogenation to polyols
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In this paper, hollow Ni ? P nanospheres (NSs) are prepared through Ni electroless plating on the Au-activated silica NSs externally covered by aminopropyl moieties, followed by removing the silica template with sodium hydroxide. With various characterizations, the resulting hollow Ni ? P NSs are identified to be amorphous alloy. During liquid-phase hydrogenation of sugars to sugar alcohols, the hollow Ni ? P amorphous alloy NSs delivered much superior catalytic performances to the commercial Raney Ni catalyst, showing a good potential in practical applications. Of particular interest is the unique hollow chamber structure of the hollow Ni ? P amorphous alloy NSs, which allows for improving catalytic activity and durability relative to those associated with the dense Ni ? P amorphous alloy NSs. This work demonstrated that such hollow Ni materials with nanoporous chamber structure displayed advantages such as easy experimental handling and high accessibility for the reactants in liquid-phase reaction, more Ni active sites, as well as the existence of more electron-enriched inner surface, which is essential to provide highly efficient catalysts for some reactions.
- Yong, Yang,Huajun, Gu,Qingxiao, Zhang,Fang, Zhang,Hui, Li
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p. 282 - 290
(2020/04/27)
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- COMPOSITIONS CONTAINING SUCRALOSE AND APPLICATION THEREOF
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Novel utilization of sucralose which is a high intense sweetener. Compositions containing sucralose including: sweetening compositions having excellent sweetness qualities based on the characteristics of sucralose; foods with a masked unpleasant smell and unpleasant taste; performance food compositions (viscous food compositions, gel food compositions, emulsified food compositions); foods with improved flavors; preservatives and foods with improved quality of taste; and flavor compositions with improved flavors. Novel utilization of sucralose as a sweetener improver, a masking agent for unpleasant smell/unpleasant taste, a flavor improver, a function improver (viscosity, gelling properties, emulsification properties), a taste characteristic improver, and a flavor improver/enhancer.
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- RECTANGULAR PARALLELEPIPEDAL MALTITOL
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The invention concerns maltitol crystals, characterized in that they have a rectangular parallelepipedal shape and have a length to width dimensional ratio in the range 1.8 to 5.3, preferably 3±0.7, and a process for producing them.
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Page/Page column 7
(2009/07/25)
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- Composition and method for stimulating pollen germination
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Composition for application, in particular to leaves, comprising an excipient, the conventional constituents of compositions for application, in particular to leaves, and an active ingredient, characterized by the fact that the active ingredient is constituted by at least one phytosanitary product capable of stimulating the germination of pollen grains, selected from the group comprising: oligosaccharides having a degree of polymerization up to 10 and comprising up to 10, preferably up to 5 and, even more preferably, two glucidic units linked by β1-3, β1-4 et α1-3, particularly those of the group comprising laminaribiose, cellobiose, nigerose, laminaritriose, laminaritetraose and laminaripentaose, derivatives of the above oligosaccharides substituted on the free anomeric carbon atom or on all the carbon atoms having a free hydroxide by a radical selected from the group comprising: C1to C5alkyl radicals, preferably the methyl radical, C1to C5acyl radicals, preferably the acetyl radical, aryl radicals, preferably pyridylamino radicals, cycloalkyl radicals from Cxto Cy, amines, the N-acetyl radical and sulfate and phosphate radicals.
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- Method of preparing lacitol monohydrate and dihydrate
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The invention relates to the new product lactitol monohydrate and to a method for the production of crystalline lactitol. The crystalline lactitol monohydrate can be obtained bij seeding an aqueous lactitol solution of a special concentration under special conditions causing the lactitol monohydrate to crystallize and recovering the product. From the mother liquor a further amount of lactitol dihydrate can be recovered. Crystalline lactitol dihydrate can be obtained using different special conditions. Lactitolmonohydrate can further be obtained by mixing one part bij weight of an aqueous lactitol solution of a suited concentration with 1 tot 3 parts bij weight of methanol or ethanol and cooling the mixture to 15° tot 25° C.
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- Crystalline mixture solid containing maltitol and a process for preparing it
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The crystalline mixture solid containing maltitol of the present invention has a crushed and relatively tight crystal structure which can be observed at 1,000 magnifications by a scanning electron microscope, an apparent specific gravity in the range of 0.650-0.750, an oil absorptivity of the powdered crystalline mixture solid containing maltitol having a particle size from 50 mesh to 20 mesh in the range of 7.0%-17%, in other words, is relatively heavy in apparent specific gravity and low in oil absorptivity, and the crystalline mixture solid containing maltitol is prepared by continuously supplying an aqueous solution of maltitol to an extruder provided with elongated cooling and kneading zones, cooling and kneading it in the presence of seed crystals to form a maltitol magma, and continuously extruded from a nozzle.
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- Sequential removal of monosaccharides from the reducing end of oligosaccharides and uses thereof
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Methods are provided for the sequential removal of monosaccharides from the reducing end of oligosaccharides. The present invention also discloses the use of such methods for structural determinations of oligosaccharides and to enable new structures to be generated from pre-existing oligosaccharides. In addition, the methods of the present invention may be automated by the incorporation into systems.
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- Crystalline mixture solid containing maltitol and a process for preparing it
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The crystalline mixture solid containing maltitol of the present invention has a crushed and relatively tight crystal structure which can be observed at 1,000 magnifications by a scanning electron microscope, an apparent specific gravity in the range of 0.650-0.750, an oil absorptivity of the powdered crystalline mixture solid containing maltitol having a particle size from 50 mesh to 20 mesh in the range of 7.0%-17%, in other words, is relatively heavy in apparent specific gravity and low in oil absorptivity, and the crystalline mixture solid containing maltitol is prepared by continuously supplying an aqueous solution of maltitol to an extruder provided with elongated cooling and kneading zones, cooling and kneading it in the presence of seed crystals to form a maltitol magma, and continuously extruded from a nozzle.
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- Hydrolysis of Substrate Analogues Catalysed by β-D-Glucosidase from Aspergillus niger. Part III. Alkyl and Aryl β-D-Glucopyranosides
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The hydrolysis of eighteen alkyl and aryl β-D-glucopyranosides and the disaccharides methyl β-cellobioside (reference substrate), cellobitol, methyl β-gentiobioside, and methyl α-C-gentiobioside catalysed by β-D-glucosidase from Aspergillus niger has been studied using 1H NMR spectroscopy and progress-curve enzyme kinetics in both single-substrate and competition experiments.The influence of chain length and stereochemistry of alkyl groups and substitutions of phenyl groups revealed that this enzyme has evolved preferentially to hydrolyse cellobiose despite low aglycone specificity.The implications of steric and polar or non-polar effects, which were shown to be important for the active site interactions on the energetics of the enzymatic activity as inferred from the kinetic experiments, are discussed.
- Sigurskjold, Bent W.,Haunstrup, Ib,Bock, Klaus
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p. 451 - 458
(2007/10/02)
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- SYNTHESIS OF A CLOSE ANALOG OF THE REPEATING UNIT OF THE ANTIFREEZE GLYCOPROTEINS OF POLAR FISH
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The protected glycopeptide N-(benzyloxycarbonyl)-L-alanyl-3)-O-(2,4,6-tri-O-benzyl-α-D-galactopyranosyl)-(1->3)>-L-threonyl-L-alanine 2,2,2-trichloroethyl ester (21) was made by coupling the respective disaccharide and tripeptide blocks.The disaccharide block was generated by coupling tetra-O-benzoyl-α-D-galactopyranosyl bromide to allyl 2,4,6-tri-O-benzyl-α-D-galactopyranoside and converting the product into O-(2,3,4,6-tetra-O-benzoyl-β-D-galactopyranosyl)-(1->3)-2,4,6-tri-O-benzyl-α-D-galactopyranosyl chloride (6) via the 1-propenyl glycoside and the free (1-OH) sugar.Alternatively, the 1-propenyl intermediate was obtained directly by using 1-propenyl 2,4,6-tri-O-benzyl-α-D-galactopyranoside (10) as the acceptor in the initial coupling reaction.An efficient 3-step synthesis of 10 was accomplished by the dibutyltin oxide-assisted, selective crotylation of allyl α-D-galactopyranoside at O-3, followed by benzylation and treatment of the product with potassium tert-butoxide.The N-benzyloxycarbonyl (Z) and N-tert-butoxycarbonyl (Boc) 2,2,2-trichloroethyl esters of Thr-Ala and Ala-Thr-Ala were formed by sequential coupling.The silver triflate-promoted glycosylation of the Z-protected dipeptide and tripeptide by 2,3,4,6-tetra-O-benzyl-α-D-galactopyranosyl chloride, and of the tripeptide by 6, proceeded with excellent α-stereoselectivity.From the disaccharide tripeptide 21, the carboxyl-deprotected and fully deproptected derivatives were prepared.
- Anisuzzaman, Abul Kashem M.,Anderson, Laurens,Navia, Juan L.
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p. 265 - 278
(2007/10/02)
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- The assembly of oligosaccharides from "standardized intermediates": beta-(1----3)-linked oligomers of D-galactose.
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Several 2-O-benzoyl-4,6-di-O-benzyl-3-O-R-alpha-D-galactopyranosyl chlorides, designed as general precursors of beta-linked, interior D-galactopyranosyl residues in oligosaccharides, were tested in a sequential synthesis of the galactotriose beta-D-Galp-(1----3)-beta-D-Galp-(1----3)-D-Gal (19). The chlorides having R = tetrahydro-2-pyranyl and tert-butyldimethylsilyl gave excellent results, whereas those having R = 3-benzoylpropionyl and chloroacetyl were unsatisfactory. An activated disaccharide block (17), having R = 2,3-di-O-benzoyl-4,6-di-O-benzyl-beta-D-galactopyranosyl, was also prepared and tested as a glycosyl donor. The coupling of 17 to 1-propenyl 2-O-benzoyl-4,6-di-O-benzyl-alpha-D-galactopyranoside (14), in the molar ratio 1.13:1, gave 64% of a trisaccharide derivative (18) that could be converted into 19. This latter synthesis of 19 is efficient because all three galactose units are derived from 14 or its immediate precursor.
- Chowdhary,Navia,Anderson
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p. 173 - 185
(2007/10/02)
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