Showing papers in "Carbohydrate Research in 1991"

TL;DR: In this paper, two alternative hypotheses for the mechanism of dehydration of xylose to 2-furaldehyde (furfural), namely (1) a succession of reactions proceeding mainly via open-chain intermediates, and (2) an acid-catalyzed sequence proceeding through a 2,5-anhydride intermediate, are reviewed and found to favor (2).

TL;DR: The composition and sequence of 2-acetamido-2-deoxy-beta-D-glucose (GlcNAc) and GlcN) residues in partially N-deacetylated chitosans, prepared under homogeneous and heterogeneous conditions, have been determined by 1H-n.r.m. spectroscopy.

TL;DR: Improved analytical methods have been applied successfully to kappa-, iota-, and lambda-carrageenans, as well as some agars, enabling the rapid determination of the substitution pattern of these polysaccharides.

TL;DR: The marked dependence on concentration in the "semi-dilute" region was similar to that for other stiff neutral polysaccharide systems, ascribed to "hyper-entanglements", and it is suggested that these may have arisen through a tenuous alignment of stiffened chains.

TL;DR: The ability to prepare a immunologically active, non-toxic, water-soluble beta-D-glucan preparation will greatly enhance the clinical utility of this class of compounds.

TL;DR: Hydrolysis of bamboo shoot cell-walls with Driselase (a fungal enzyme preparation) released a diferuloyl arabinoxylan hexasaccharide, the first reported evidence that arabinxylans are covalently cross-linked via diferulic acid.

TL;DR: Chitosans that were N-deacetylated under homogeneous and heterogeneous conditions gave values for the diad and triad frequencies that were consistent with a random arrangement of GlcN and GlcNAc residues.

TL;DR: The order-disorder transition that occurs on heating an aqueous suspension of starch granules has been investigated using differential scanning calorimetry (d.s.c.), X-ray crystallinity, and birefringence methods.

TL;DR: The relationship between the conformation of (1----3)-beta-D-glucans in gel or hydrated form and the stimulation of two types of biological responses, namely, activation of coagulation Factor G from limulus amebocyte lysate and host-mediated antitumor activity was examined.

TL;DR: Results suggested a highly branched, new type of fucan sulfate containing a backbone of (1----3)-linked L-fucosyl residues having sulfate groups mainly attached to C-4.

TL;DR: In this paper, light-scattering measurements on samples of chitosan with degrees of acetylation (d.a.) of 42 and 15% have been performed in 0.1 m acetic acid-0.2 m sodium chloride.

TL;DR: A xylan has been synthesized in yields up to 64% by thermal polymerization of methyl β- d -xylopyranoside, catalyzed by phosphoric acid as mentioned in this paper.

TL;DR: The structure of penta-to hepta-saccharides, generated by digestion of purified wheat-endosperm arabinoxylan with endo-(1----4)-beta-D-xylanase and isolated by gel-permeation chromatography on Bio-Gel P-6 followed by high-performance anion-exchange chromatography with pulsed amperometric detection, was established using monosaccharide and methylation analysis, f.a.b.-m.r.

TL;DR: In this article, aldoses were derivatized to their 3-methyl-1-phenyl-2-pyrazolin-5-one derivatives and analyzed by capillary zone electrophoresis as their borate complexes.

TL;DR: Grouping of lectin-binding properties, based on determinant structure rather than monosaccharide-inhibition pattern, should facilitate the selection of lectins as structural probes for glycans, as well as for the interpretation of the distribution and the properties of the carbohydrate chains on the cell surface.

TL;DR: In this article, cell-wall polysaccharides were solubilised from kiwifruit at 2 ripening stages, after treatment for 1 and 7 days with ethylene.

TL;DR: In this article, a graphitized carbon column was used for the analysis of cyclomaltaoses on HyperCarb, and cyclohexyloxylose, d-glucose and l-fucose were separated using a pulsed amperometric detector.

TL;DR: This O-antigen is related in structure to those of Pseudomonas aeruginosa O6, immunotype 1, and IID 1008, and Shigella dysenteriae type 7.

TL;DR: In this article, the distribution of substituents in the alkyl cellulose ethers was determined by acid hydrolysis, reduction, and gas-chromatographic separation of the partially alkylated alditol acetates.

TL;DR: 2-Dansylamino-2-deoxy-D-galactose (GalNDns) has been shown to bind to peanut (Arachis hypogaea) agglutinin (PNA) in a saccharide-specific manner and PNA interacts with several T-antigen-related structures, including the asialo-GM1 tetrasaccharide with comparable affinity.

TL;DR: Two anti-complementary polysaccharide fractions isolated from the roots of Glycyrrhiza uralensis Fisch et D.C. showed more potent anti- complementary activities than the original polysacchide fractions, whereas the intermediate fractions and oligogalacturonides were inactive.

TL;DR: In this paper, the voltammetric and chronoamperometric responses are described for selected carbohydrates, and guidelines are given for selection of optimal potential and time parameters in the waveform to be used for l.c.-p.a.d.

TL;DR: In this paper, various oligo- and poly-saccharides differing in sugar compositions and types of linkage were examined for their ability to activate a limulus coagulation factor G, the first protease in an alternative coagulations cascade of the horseshoe crab, Tachypleus tridentatus, whose amebocytes have originally been known to contain a lipopolysacchaide(LPS)-driven pathway leading to the formationof coagulin gel.

TL;DR: In this paper, the capacity factors for monosaccharides and sugar alcohols were investigated on three quaternary ammonium columns of the same size and virtually the same composition under identical eluent flow rates (1 mL·min−1) and compositions (aqueous 0.1 n NaOH).

TL;DR: The results indicated that the relative amount of the L-31 lectin increases as the colorectal cancer progresses to a more malignant stage.