Showing papers in "Carbohydrate Research in 1968"

TL;DR: The structure of the O-specific side-chains of the cell-wall lipopolysaccharide of Salmonella typhimurium 395 MS has been investigated and a detailed structure ofThe repeating unit of these side- chains is presented.

TL;DR: In this paper, the existence of an axial, electronegative substituent adjacent to a sulphonate group on a pyranose ring inhibits replacement with charged nucleophiles, because of polar factors in the transition state of the reaction.

TL;DR: In this article, the degradation of heparitin sulfate with nitrous acid at −20° has been shown to be a useful technique for the study of structural features of this mucopolysaccharide.

TL;DR: A modified procedure for replacing the O-acetyl groups in partially acetylated dextran with the stable O-methyl group, using methyl vinyl ether as protective reagent, is described in this paper.

TL;DR: In this article, all of the likely conformations of cellobiose, cellulose, and xylan have been explored systematically by using an electronic computer, assuming the ring conformations and (C-1)-O-(C-4′) angle for each pair of residues to be fixed and derivable from known crystal structures.

TL;DR: The results of methylation studies on both kefiran and kefirose, of periodate-oxidation analysis of kefIRan, and of a study on the products of partial hydrolysis of keFirose with acid provided substantial evidence for assigning the following structures to kefirese and keFiran, respectively.

TL;DR: In this paper, the aldehyde 2 was characterized as the crystalline 6-oxime and 6-(p -nitrophenyl)hydrazone (p-NH) hydrazone.

TL;DR: In this paper, an acid-catalyzed, stereoselective rearrangement of the 3,4,6-tri-O-benzyl-β-D -mannose 1,2-(alkyl orthoacetates) was observed.

TL;DR: The pectin isolated from dried lemon-peel by extraction with cold water has been subjected to partial depolymerisation by acid hydrolysis, acetolysis, and enzymic degradation.

TL;DR: In this paper, N,N-dimethylformamide was used as a solvent and 1.5-2.0 molar equivalents of phosphorus pentaoxide was used to oxidize secondary alcohol groups of carbohydrates to ketones.

TL;DR: It is concluded that from the mass spectra alone it is possible to determine the molecular weight, the cycle masses as well as the mode of linkage between the monomeric units.

TL;DR: In this article, the pmr spectra of commercial heparin samples from a variety of sources indicate that there are at least two types of heparins, differentiated by small, but distinct, variations in the relative intensities of their proton signals and, most noticeably, by the presence of acetyl groups in samples of one of the types.

TL;DR: In this article, axial and equatorial O -and N -acetyl-resonances of cyclitol and aminocyclitol polyacetates were derived for axial O(n)-acetyl and N-acetyl resonance.

TL;DR: In this article, the analytical parameters for Acacia senegal gum have been determined for twelve bulk samples of tapped gum from three different districts of the Sudan, and thirteen single-nodule specimens of natural exudate gum.

TL;DR: No completely satisfactory procedure was found for following the oxidation reaction to termination, which, in none of the cases studied, was 100% complete.

TL;DR: In this article, a sulphated glucuronoxylofucan containing L -fucose (49%), D -xylose (10%), and D -glucuronic acid (11%) has been extracted from the cell-walls of Ascophyllum nodosum, after removal from the weed of laminaran, fucoidan, and the major part of the alginic acid.

TL;DR: The levan from Streptococcus salivarius has an intrinsic viscosity of 0.15–0.16 dl/g and has a molecular weight of 16–23 million, and the biological implications of these properties have been discussed.

TL;DR: The cell-wall D -glucan of bakers' yeast has been shown by methylation and periodate oxidation studies to be a β-(1→3)- D-glucans having branches at C-6 as discussed by the authors.

TL;DR: In this paper, it was shown that Uronic acids are subject to irreproducible lactonisation under conditions used in hydrolysis of polysaccharides, and methods have been devised for the quantitative separation from reducing sugars without alkaline degradation or rearrangement.

TL;DR: In this paper, it is shown that there is definite evidence for the absence of rigid helical segments in amylose in aqueous solution. But the significance of the exponent in this relation and others in the literature is discussed.

TL;DR: For the potassium chloride-soluble fractions of five carrageenans, correlations have been established between 3,6-anhydrogalactose content and the products of methylation and fragmentation.

TL;DR: Temperature, chelating agents, protein denaturants, and alpha- and beta-amylolysis on concanavalin A—polysaccharide complexes have been studied, and hydrogen bonding plays an important role in their binding.

TL;DR: In this paper, the mass spectra of methyl ester methyl glycosides of methylated uronic acids, methyl esters methyl glyco-gensides of aldobouronic acids of different types, and of methyl Ester methyl co-gems of acetylated aldobiouronic acid having 4-O -methyl-d -glucuronic acid as the acidic component were obtained.

TL;DR: In this article, the 3-O-(L -1-carboxyethyl) derivatives were separated as their methyl esters, and only from the condensation of the methyl α-D -glucoside was a significant proportion (11% yield) achieved.

TL;DR: In this paper, the four O-β-d -glucopyranosyl(1 → x)-O-β -d -gluopyranoyl (1 → 1)-d -glycerols (x = 2, 3, 4, or 6) have been synthesized and shown to be distinguishable by paper and gas-liquid chromatographic techniques.

TL;DR: In this paper, a water-insoluble α-amylase was reported to have greater heat stability than the native α-AMylase, 20% of the original activity remaining after 7 days at 45°.

TL;DR: The O-acetylated O-(β-glycopyranosyl)- l -serine derivatives of d -galactose, lactose, cellobiose, 2-acetamido-2-deoxy- and 2-deoxyloxycarbonyl-l-serine benzyl ester were synthesized by Koenigs and Knorr as mentioned in this paper.

TL;DR: In this paper, a Mark-Houwink relation between amylose and three thermodynamically good solvents (formamide (F), methyl sulphoxide (Me2SO), and aqueous potassium hydroxide (KOH) was obtained.