Showing papers in "Carbohydrate Research in 1979"

TL;DR: The absolute configuration of neutral monosaccharides, 2-acetamido-2-deoxy sugars, and uronic acids can be determined by capillary g.l.c. on SE-30 after glycosidation with (-)-2-butanol and protection of the remaining polar groups.

TL;DR: The sequence and composition of uronate residues in intact alginate samples have been obtained by high-resolution 1H-n.m.r. spectroscopy.

TL;DR: In this article, a series of water-soluble arabinoxylans has been prepared from purified wheat-flour arabin oxylan by partial removal of arabinosyl side-branches using an α-L -arabinofuranosidase.

TL;DR: The conformation of xanthan has been investigated as a function of temperature, ionic strength, and polymer concentration; a reversible transition induced by temperature is demonstrated; the melting temperature is directly correlated to the total ionic-strength and is independent of the polymer concentration.

TL;DR: The role of the major variables in the pyrolytic production of levoglucosenone from acid-treated cellulose and paper has been established as discussed by the authors, and reduction, oxidation, acid-and base-catalyzed addition, acetolysis, and rearrangement reactions of this product have been investigated.

TL;DR: In this article, a perturbational PMO treatment was applied to calculate orbital interactions between XCH2 and YH in the cases of anomeric and exo-anomeric effects.

TL;DR: A direct correlation between the extent of hydrolysis of d -galacto- d -mannans by β- d-mannanase and the degree of gelling interaction with xanthan gum was observed, suggesting that interaction of d-galactosyl residues from the d -mannotriose backbone does not absolutely require long sections of contiguous unsubstitutedd -mannose residues.

TL;DR: In this article, the chemical and physical properties of a natural (1→3)-β-d -glucan found in Euglena gracilis and curdlan were compared to each other and it was concluded that this system is a "native-regenerated" pair just as the well known "native cellulose-generated cellulose" system.

TL;DR: In this article, the advantages and limitations of this method are discussed, and the addition of methanol to the eluant and lowering of the temperature improve the separation of polyols and their derivatives.

TL;DR: Treatment of the N-deacylated polysaccharide with nitrous acid caused deamination with concomitant rearrangements, typical of 4-amino-4-deoxyhexopyranosyl residues in which the amino group occupies an equatorial position.

TL;DR: The production of dextransucrase from Leuconostoc mesenteroides NRRL B-512F was stimulated 2-fold by the addition of 0.005% of calcium chloride to the medium; levansucrase levels were unaffected; and the mannoglycoprotein character of the enzyme was confirmed.

TL;DR: In this article, the initial behavior of a series of monosaccharides in aqueous, alkaline medium has been studied by using u.v. spectroscopy, and the reaction rate constants have been determined for both the formation and the conversion of the enediol anion by using the overall reaction scheme: sugar + -OH α sugar anion α enedi anion → β-elimination intermediates → products.

TL;DR: In this paper, a structure incorporating these features for the husk polysaccharide was proposed for the plantago ovata Forsk, which was shown to be a highly branched, acidic arabinoxylan backbone with both 1→4 and 1→3 linkages, and the majority of the residues in the xylan backbone are variously substituted with arabinose, xylose, and an aldobiouronic acid identified as 2- O -(galactopyranosyluronic acid)-rhamnose.

TL;DR: In this article, the n.m.r. spectra of most of the methyl aldofuranosides were determined and analyzed, and from the data, the conformations of the glycosides have been deduced.

TL;DR: In this paper, a 13C-n.m.r. study of sodium hydroxide-induced, conformational change was performed on branched (1 → 3)-β-d-glucans, showing that the peak intensity and line width of the 13Cresonance peaks for the gel state are strongly influenced by the degree of cross-linking.

TL;DR: Methylation, periodate oxidation, and partial hydrolysis studies revealed that the glucuronic acid is 1,3-linked and is attached solely to O–3 of D -galactose in both mucilages.

TL;DR: In this article, it was shown that methylated cycloamyloses, when used as the stationary phases for g.l.r.c. or dissolved in a conventional stationary phase, affect the retention times of organic compounds in a manner which suggests that inclusion phenomena are operative.

TL;DR: The mucilaginous jelly from the leaves of Aloe vera is composed of at least four different partially acetylated glucomannans that differ in their glucose-to-mannose ratios and acetyl contents.

TL;DR: In this paper, the resonance properties of the D -glucopyranosyl group in maltulose and isomaltulose have been investigated and the resonance assignments for the D-fructofuranosyl residues of inulin have been made.

TL;DR: In this paper, the stereoisomeric pairs of pyruvic acid and related acetals linked to the 3,4- and 4,6-positions, respectively, of the anomeric methyl d -galactopyranosides and the corresponding acyclic CH3 groups were determined.

TL;DR: In this article, Stannic chloride-catalysis was used for rearrangement of 3,4,6-tri-O -acetyl-1,5-anhydro-2-deoxy-d -hex-l-enitol.

TL;DR: Two-, three-, and four-carbon aldononitriles were prepared, and catalytically reduced with palladium-barium sulfate (5%) to the coresponding aldoses in high yields at pH 1.7 ± 0.1 and atmospheric pressure.

TL;DR: In this paper, the Guthrie-Smith method for the synthesis of tetra-O-acetyl-β- d -ribofuranose has been successfully generalized to apply to the d -aldopentofuranoses series.

TL;DR: In this article, ayanide condenses with aldoses at 25° in aqueous solution between pH 7.0 and 9.0 to produce aldononitriles in high yield.

TL;DR: A detailed theoretical analysis of the kinetics of the periodate oxidation of guaran and locust-bean gum, together with the results of methylation analyses carried out by Lindberg's group on partially oxidised and barohydride-reduced samples of the galactomannans, has provided new evidence for the arrangement of the α- d -galactopyranosyl side-groups along the mannan chains.

TL;DR: 6-Aminohexyl glycosides covalently linked to solid matrices are effective reagents for the isolation of proteins that bind to carbohydrates and for the study of interactions between intact cells and immobilized carbohydrates.

TL;DR: The mucilage extracted from the modified stems of Opuntia ficus-indica contains residues of d -galactose, d -xylose, l -arabinose and l -rhamnose, and d-galacturonic acid.