ChemInform Abstract: Selective Fluorescence Signalling of Saccharides in Their Furanose Form.

ChemInform ◽  
2010 ◽  
Vol 30 (4) ◽  
pp. no-no
Author(s):  
C. R. COOPER ◽  
T. D. JAMES
Keyword(s):  
Furanose Form

The metabolism of carbohydrates by extremely halophilic bacteria: the identification of lactobionic acid as a product of lactose metabolism by Halobacterium saccharovorum

1978 ◽  
Vol 24 (8) ◽  
pp. 898-903 ◽  
Author(s):  
Geraldine A. Tomlinson ◽  
Maureen P. Strohm ◽  
Lawrence I. Hochstein
Keyword(s):  
Thin Layer ◽  
Acid Hydrolysis ◽  
Column Chromatography ◽  
Gluconic Acid ◽  
Halophilic Bacteria ◽  
Galactose Oxidase ◽  
Lactobionic Acid ◽  
Lactose Metabolism ◽  
Furanose Form

Nongrowing cells of Halobacterium saccharovorum oxidized lactose to a product identified as lactobionic acid by thin-layer, paper, and column chromatography, and by identification of the galactose and gluconic acid produced from it after acid hydrolysis. Growing cells oxidized lactose to a product that was identical with lactobionate except that it did not serve as a substrate for galactose oxidase. While the identity of this compound has not been established, it is suggested that the product is lactobionic acid in which the galactose moeity is in the furanose form. Neither lactobionate nor the product produced by growing cells was further metabolized, suggesting that lactose oxidation is not coupled to growth.

REACTION OF ALDOSES AND KETOSES WITH LEAD TETRAACETATE

1956 ◽  
Vol 34 (4) ◽  
pp. 541-553 ◽  
Author(s):  
A. S. Perlin ◽  
Carol Brice
Keyword(s):  
Lower Order ◽  
Higher Order ◽  
Lead Tetraacetate ◽  
Pyranose Form ◽  
Reaction Proceeds ◽  
Furanose Form ◽  
Rare Sugars

Lead tetraacetate is highly selective for oxidation of α-hydroxy-hemiacetal groups and hence most readily attacks cyclic forms of the sugars. The reaction proceeds stepwise; the hemiacetal α-glycol being cleaved and the monoester of a correspondingly shorter-chained sugar formed. After cyclization the new sugar in turn is oxidized at the hemiacetal α-glycol group to yield a diester of a still-lower-order member of the series. In this manner D-glucose first yields mono-O-formyl-D-arabinose and then di-O-formyl-D-erythrose. Similarly, D-fructose is degraded to a glycolate ester of D-erythrose and finally to a formate–glycolate diester of D-glyceraldehyde. Some relatively rare sugars thus may conveniently be prepared directly from abundant higher-order members of the series. The reactions appear to involve preferential attack of the furanose form of a sugar rather than of the normally-predominant pyranose form, or possibly migration of ester groups towards the reducing end of the sugars.

scholarly journals The Study of the Reaction of Pectin-Ag(0) Nanocomposites Formation

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Nadezhda Viktorovna Ivanova ◽  
Natalya Nikolaevna Trofimova ◽  
Lydmila Alexandrovna Es'kova ◽  
Vasilyi Anatolievich Babkin
Keyword(s):  
Aqueous Solutions ◽  
Larix Sibirica ◽  
Side Chains ◽  
Chemical Transformations ◽  
Reaction Conditions ◽  
Rhamnogalacturonan I ◽  
Spectroscopic Analyses ◽  
Furanose Form ◽  
Branched Structure ◽  
C Nmr

Pectin polysaccharides (PSs) were isolated from a bark of Larix sibirica Ledeb. Structure of PS fragments determined by chemical transformations, chromatography, and spectroscopic analyses was found to be a linear galacturonane comprising 1,4-linked α-D-GalpA residues and a rhamnogalacturonan I (RG-I). The fifth part of galacturonane residues was methyl esterified at at C-2 and/or C-3 and C-6 atoms. Some of RG-I side chains were identified as arabinogalactan subunits with highly branched structure consisting of linear backbone with3,6)-β-D-Galp-(1residues, substituted at C-6 by neutral side chains. This side chains contained2,5)-α-L-Araf-(1and3,5)-α-L-Araf-(1residues and terminal arabinose in the pyranose and furanose form. It was found that “pectin-Ag(0)” nanobiocomposites were formed via the interaction between PS aqueous solutions and silver nitrate, with PS playing both reducing and stabilizing functions. It was shown that the content of Ag(0) particles in “pectin-Ag(0)” depended on the reaction conditions and can range from 0.1 to 72 %, the size of Ag(0) particles being 3–27 nm. Using 13C NMR technique, it was revealed that PS underwent destructive changes and they they were more considerable, more than the lot of Ag(I) that was inputed into the reactionary medium.

Synthesis of derivatives of 4-acetamido-4-deoxy-D- and L-arabinose

1968 ◽  
Vol 46 (3) ◽  
pp. 425-434 ◽  
Author(s):  
A. J. Dick ◽  
J. K. N. Jones
Keyword(s):  
Aqueous Solution ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Acetyl Derivative ◽  
Tautomeric Equilibrium ◽  
Methanol Solution ◽  
Furanose Form ◽  
Derivatives Of

4-Acetamido-4-deoxy-D- and L-arabinose have been synthesized from methyl 4-azido-4-deoxy-D- and L-arabinopyranoside, respectively. In contrast to other 4-acetamido-4-deoxypentoses, the arabinose derivatives in aqueous solution at tautomeric equilibrium exist both in the pyranose and in the furanose forms. The presence of the furanose form (containing nitrogen as the hetero atom in the ring) has been demonstrated by paper chromatography and infrared and nuclear magnetic resonance (n.m.r.) spectroscopy. Acetolysis of methyl 4-amino-4-deoxy-α-D-arabinopyranoside hydrochloride and of the N-acetyl derivative gave 4-acetamido-4-deoxy-D-arabinofuranose tetraacetates whose anomeric configurations were assigned by n.m.r. spectroscopy. Treatment of the 4-acetamido-4-deoxy-D-arabinofuranose tetraacetates with a cation exchange resin in methanol solution and subsequent de-O-acetylation, gave the anomeric methyl 4-acetamido-4-deoxy-D-arabinofuranosides, whose n.m.r. spectra in D2O exhibited the phenomenon of hindered internal rotation.

SYNTHESIS OF CARBOHYDRATE BLOCKS FOR 2'.3'-DIDEOXYNUCLEOSIDES FROM LEVOGLUCOSENONE

2020 ◽  
Vol 0 (4) ◽  
pp. 33-39
Author(s):  
B.T. SHARIPOV ◽  
◽  
A.N. DAVYDOVA ◽  
F.A. VALEEV ◽  
◽  
...  
Keyword(s):  
Raw Materials ◽  
Total Yield ◽  
Modified Nucleosides ◽  
Hydroxyl Group ◽  
Pyranose Form ◽  
Amberlyst 15 ◽  
Immunodeficiency Virus ◽  
Furanose Form ◽  
Acquired Immunodeficiency ◽  
Immunodeficiency Syndrome

Nucleosides containing five-membered deoxy-carbohydrates in the glycosidic part, such as zalcitabine, 2'.3'-dideoxyuridine, stavudine, are widely used in acquired immunodeficiency syndrome (AIDS). A number of 2'.3'-dideoxynucleosides is an effective inhibitor of type-1 immunodeficiency virus (HIV-1) in humans. Levoglucosenone and cyrene (dihydrolevoglucosenone) are unique compounds, optically pure ketones of carbohydrate nature obtained from renewable bio-raw materials and available by pyrolysis of any cellulose-containing materials. They are promising carbohydrates for the production of modified nucleosides; in addition, they are commercially available. Based on levoglucosenone, we synthesized chiral carbohydrate blocks for dideoxy-nucleosides, namely, tertbutyldimethylsilyl derivatives of (S)-5-(hydroxymethyl)-2.5-dihydrofuran-2-ol and (S)-5-(hydroxymethyl)tetrahydrofuran-2-ol. At the first stage of the synthesis, a one-stage modification of the pyranose form of levoglucosenone and cyrene to γ-butanolides was carried out by Bayer-Williger oxidation using H2O2 in the presence of Amberlyst-15 in water. The reduction of unprotected hydroxymethyl-γ-butanolide obtained from cyrene to lactol was studied. The reduction of γ-butanolide by the action of BH3·SMe2, Red-Al, or LiAlH(OtBu)3 in THF at 0° C leads mainly to triol, the product of complete reduction. The desired lactol was obtained using iBu2AlH at -78°C in CH2Cl2 in good yield. Raising the reaction temperature to 0° C led to a decrease in the yield of lactol. It has been established that (S)-5-(hydroxymethyl)-tetrahydrofuran-2-ol exists in both five-membered and six-membered forms. Due to the fact that the target lactols easily undergo a transition from the furanose to the pyranose form, they are not used to produce nucleosides. Therefore, we have studied the approach to the synthesis of stable five- membered lactols. For this purpose, in lactones obtained by the Bayer-Williger reaction, the primary hydroxyl group was blocked using TBSCl. Subsequent reduction of the esters using iBu2AlH gave lactols that existed exclusively in the furanose form. The total yield of the target (S)-5-(hydroxymethyl)-2.5-dihydrofuran-2-ol obtained from levoglucosenone was 39% and (S)-5-(hydroxymethyl)-tetrahydrofuran-2-ol obtained from cyrene was 65%.

Addition of pseudohalogens to unsaturated carbohydrates. III. Synthesis of 3-deoxy-3-C-nitromethyl-D-allose, a branched-chain nitro sugar

1969 ◽  
Vol 47 (23) ◽  
pp. 4473-4476 ◽  
Author(s):  
W. A. Szarek ◽  
J. S. Jewell ◽  
I. Szczerek ◽  
J. K. N. Jones
Keyword(s):  
Sodium Borohydride ◽  
Wittig Reaction ◽  
Furanose Form ◽  
Acid Catalyzed ◽  
Branched Chain ◽  
Hydrolysis Of

Addition of nitryl iodide to 3-deoxy-1,2:5,6-di-O-isopropylidene-3-methylene-α-D-ribo-hexofuranose (2), followed by treatment of the product with sodium borohydride, gave crystalline 3-deoxy-1,2:5,6-di-O-isopropylidene-3-C-nitromethyl-α-D-allofuranose (3); the branched-chain unsaturated sugar (2) was prepared by way of a Wittig reaction with 1,2:5,6-di-O-isopropylidene-α-D-ribo-hexofuranos-3-ulose (1). Acid-catalyzed hydrolysis of 3 afforded 3-deoxy-3-C-nitromethyl-D-allose, which exists predominantly in the β-D-furanose form (4).

AN EXTRACELLULAR POLYSACCHARIDE FROM GIBBERELLA FUJIKUROI (FUSARIUM MONILIFORME)

1961 ◽  
Vol 39 (8) ◽  
pp. 1683-1694 ◽  
Author(s):  
I. R. Siddiqui ◽  
G. A. Adams
Keyword(s):  
Fusarium Moniliforme ◽  
Glucuronic Acid ◽  
Periodate Oxidation ◽  
Extracellular Polysaccharide ◽  
Gibberella Fujikuroi ◽  
Molar Ratio ◽  
Glucose Medium ◽  
Mannuronic Acid ◽  
Acid Protein ◽  
Furanose Form

Growth of Gibberellafujikuroi (Fusariummoniliforme) on a glucose medium produced au extracellular polysaccharide containing D-glucose, D-mannose, D-galactose, D-glucuronic acid (molar ratio 1.0:1.1:1.3:0.6), and possibly D-mannuronic acid. Protein was retained tenaciously by the polysaccharide and several deproteinization methods reduced the nitrogen content only slightly. Methylation studies showed that the polysaccharide was highly branched with D-glucose and D-mannose forming the non-reducing ends in the molecule. Most of the D-mannose and D-galactose units were joined by 1 → 2 and 1 → 6 linkages with some branching also at C2 and C6 positions; D-galactose occurred exclusively in the furanose form. D-Glucose units were joined by 1 → 2 and 1 → 3 linkages. The D-glucuronic acid residues were mainly non-terminal and were attached to both D-galactose and D-mannose units. Periodate oxidation studies supported the foregoing conclusions.

Evidence for molybdate complexes of ketoses and aldosesin the furanose form: a 13C and 1H NMR study

1992 ◽  
Vol 237 ◽  
pp. 23-32 ◽  
Author(s):  
Jean-Paul Sauvage ◽  
Stella Chapelle ◽  
Jean-François Verchère
Keyword(s):  
1H Nmr ◽  
Nmr Study ◽  
Furanose Form
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