- FUNGAL ENZYMIC ACTIVITY DEGRADING 1,4-α-D-GLUCANS TO 1,5-D-ANHYDROFRUCTOSE
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1,5-D-Anhydrofructose, the precursor of the antibiotic pyrone microthecin in morels and other fungi, is produced in Morchella vulgaris by a novel enzymic activity, presumably a lyasic one, which acts specifically on openchain 1,4-α-D-glucans; it can be prepared enzymatically in vitro from starch in 40 to 50percent yield.Key Word Index - Morchella vulgaris; M. costata; fungi; morels; cortacerone; mircothecin; carbohydrates; pyrones; glucosone; 1,5-D-anhydrofructose; bioconversion; 1,4-α-D-glucan; starch; glycogen.
- Baute, Marie-Antoinette,Baute, Robert,Deffieux, Gerard
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- Purification, characterization, and molecular cloning of a pyranose oxidase from the fruit body of the basidiomycete, Tricholoma matsutake
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A new H2O2-generating pyranose oxidase was purified as a strong antifungal protein from an arbuscular mycorrhizal fungus, Tricholoma matsutake. The protein showed a molecular mass of 250 kDa in gel filtration, and probably consisted of four identical 62 kDa subunits. The protein contained flavin moiety and it oxidized D-glucose at position C-2. H2O 2 and D-glucosone produced by the pyranose oxidase reaction showed antifungal activity, suggesting these compounds were the molecular basis of the antifungal property. The Vmax, Km, and kcat for D-glucose were calculated to be 26.6 U/mg protein, 1.28 mM, and 111/s, respectively. The enzyme was optimally active at pH 7.5 to 8.0 and at 50°C. The preferred substrate was D-glucose, but 1,5-anhydro-D-glucitol, L-sorbose, and D-xylose were also oxidized at a moderate level. The cDNA encodes a protein consisting of 564 amino acids, showing 35.1% identity to Coriolus versicolor pyranose oxidase. The recombinant protein was used for raising the antibody.
- Takakura, Yoshimitsu,Kuwata, Shigeru
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- Expedient conversion of d-glucose into 1,5-anhydro-d-fructose and into single stereogenic-center dihydropyranones, suitable six-carbon scaffolds for concise syntheses of the soft-coral constituents (-)-bissetone and (-)-palythazine
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High-yielding protocols are described to convert d-glucose-via hydroxylaminolysis of its hydroxyglucal esters, followed by deoximination and β-elimination of acid-into dihydropyranone building blocks with a single stereogenic center. Their versatility as enantiopure six-carbon scaffolds is highlighted by excellent regio- and stereocontrol in a variety of addition reactions and by their straightforward use as building blocks for the concise syntheses of the soft-coral constituents bissetone and palythazine in enantiopure form, thereby proving their absolute configuration. Moreover, several procedures are detailed to convert hydroxyglucal esters into 1,5-anhydro-d-fructose, their parent sugar, the direct low-temperature de-O-acylation being the most suitable for preparative purposes, as long as its access via enzymatic degradation of starch is not implemented on an appreciable scale.
- Brehm, Manfred,Goeckel, Volker H.,Jarglis, Pan,Lichtenthaler, Frieder W.
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p. 358 - 373
(2008/09/19)
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- 1,5-Anhydro-d-fructose from d-fructose
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1,5-Anhydro-d-fructose was efficiently prepared from d-fructose via regiospecific 1,5-anhydro ring formation of 2,3-O-isopropylidene-1-O-methyl(tolyl)sulfonyl-d-fructopyranose and subsequent deprotection.
- Dekany, Gyula,Lundt, Inge,Niedermair, Fabian,Bichler, Sabine,Spreitz, Josef,(Fitz) Sprenger, Friedrich K.,Stuetz, Arnold E.
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p. 1249 - 1253
(2008/02/02)
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- 1,5 AND 1,4-ANHYDROKETOSES, METHODS FOR THE PREPARATION OF 1,5-AND 1,4-ANHYDROKETOSES, INTERMEDIATES, AND USES OF 1,5-AND 1,4-ANHYDROKETOSES
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The present invention relates to 1,4- and 1,5-anhydro-D-ketoses (monosaccharides, oligosaccharides and various glycoconjugates), e.g. 1,5-anhydro-D-fructose. Moreover, the invention provides synthetic methods and novel intermediates and precursors suitable for their preparation. The methods include catalytic- and/or pyrolitic sulfenic acid elimination of corresponding ?-hydroxy sulfoxides, N-deprotection of N-substituted-aminoglycals, O-deprotection of carbohydrate enolethers and/or O-acyl-substituted carbohydrate enols, and regio- and stereoselective modification and subsequent chemical transformation of bicyclic and/or tricyclic 1,4- and 1,5-anhydro-glycoderivatives. Furthermore, the present invention provides novel applications of 1,4- and 1,5-anhydroketoses within pharmaceutical, food and cosmetic industries.
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Page/Page column 75-76
(2008/06/13)
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- A CONVENIENT ACCESS TO 1,5-ANHYDROKETOSES
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A convenient, verstile entry into the 1,5-anhydroketose series is described and their conversion into enolones, enolone oximes and γ-pyrones.
- Lichtenthaler, F. W.,Ashry E. S. H. El,Goeckel, V. H.
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p. 1429 - 1432
(2007/10/02)
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