Showing papers in "Carbohydrate Research in 1971"

TL;DR: This article showed that the concept that agar is made up of two polysaccharides, neutral agarose and charged agaropectin, is an over-simplification.

TL;DR: The Raman spectra of V a, Vh h, and B -amylose have been recorded, and are interpreted in terms of the proposed mechanism for conversion from the V- into the B-form as mentioned in this paper.

TL;DR: In this article, 6-O-p-Toluenesulphonyl-cyclohexaamylose was obtained by nucleophilic displacements of the sulphonate group of the monotosyl-cycloeaamyloses.

TL;DR: Nojirimycin can be used to differentiate between α-glucosidase and exo-α- d -glucanase, and between β-gloucono-1,5-lactone and ex-β- β-d -glugal, and the structural similarity of the two inhibitors is discussed.

TL;DR: A series of linear amylose oligomers has been synthesized enzymically to yield samples having the number-average degree of polymerisation, DPn¯, in the range 22 to 134.

TL;DR: In this paper, the infrared spectra of α-glucose and three C-deuterated d -glucoses in water and deuterium oxide were compared.

TL;DR: Addition of calcium ions during the growth period demonstrated a change in the ratio of uronic acids in thePolyuronide produced was strongly dependent upon the calcium concentration in the growth medium; low levels of calcium favoured the production of polyuronides rich in D -mannuronic acid, whereas the polysaccharides richest in guluronic Acid seemed to be obtained at intermediate concentrations of calcium.

TL;DR: An enzyme preparation was isolated from liquid cultures of Azotobacter vinelandii by precipitation with ammonium sulphate after removal of cells by centrifugation and attempts were made to follow the formation of the two different types of L-guluronic acid-containing blocks during the epimerization reaction.

TL;DR: In this article, a new catalyst-solvent system (1,2-dichloroethane or chlorobenzene and pyridinium or 2,6-dimethylpyrinium perchlorate) was described for glycosylation.

TL;DR: In this paper, the analysis of extracted cottonwood showed the presence of lignin and 76.1% of cell-wall polysaccharides, including cellulose (44.1%), 4-O -methylglucuronoxylan (20.8%), and glucomannan (9.7%).

TL;DR: A disaccharide derived from heparin was shown to be an elimination product having the probable structure 1 ; namely, 4- O -(4-deoxy-α- L - threo -hex-4-enopyranosyluronic acid 2-sulfate)-(2-deox-2-Sulfoamino)-α- D -glucopyranose 6-sulphate) as mentioned in this paper.

TL;DR: Chemical and enzymic analyses, coupled with fractionation of the agars on DEAE Sephadex A-50, have shown the differences in the series of related polysaccharides which constitute different agar.

TL;DR: In this paper, the Koenigs-Knorr condensation of the bromide with benzyl 2-acetamido-3,4-di-O -acetyl-2-deoxy-α-D -glucopyranoside and removal of protecting groups afforded 2.3.4.tri-O(tri- O -benzyl-α,β-L -fucopyrusyl- D-glucose 65% yield, the product containing a 7:3 ratio of α to β anomers.

TL;DR: In this article, the first step in the reaction is an abstraction of H-5, and it is suggested that the first layer of the abstraction is an extraction of H5 from the water.

TL;DR: It is concluded that about 40% of the side chains in dextran NRRL B-512 contain only one d -glucose residue, at least 45% are two d - glucose units long, and the rest (max. 15%) are longer than two such units.

TL;DR: In this article, the carboxyl groups of mucopolysaccharides were converted into substituted amides of amino acids by the activation of the CARB with a water-sensor.

TL;DR: Agar consists of a spectrum of polysaccharides with three extremes in structure, namely, neutral agaroses, pyruvated agarose having little sulphation, and a sulphated galactan as discussed by the authors.

TL;DR: It is suggested that the two forms of glucoamylase are isoglycoenzymes, probably due to a difference in the number of amide groups or glycosylaminically linked carbohydrate units in the polypeptide chains.

TL;DR: The molecular weight and sulfur content of the reaction products obtained by treatment of amylopectin, cellulose, dextran, chitin, alginic acid, chondroitin 6-sulfate, and chitosan with concentrated sulfuric acid for 2 h at 0° were determined as mentioned in this paper.

TL;DR: The structure of the common core polysaccharide connecting the O-antigenic side-chains to the lipid part in the Salmonella typhimurium lipopolysacc is described in this paper.

TL;DR: In this article, the physical properties of 1,6-anhydro-β-D -glucopyranose were analyzed and the presence of zinc chloride and sodium hydroxide was shown to promote dehydration and charring.

TL;DR: The separation and structural analysis of 21 trisaccharides as their permethylated triscaride alditols by gas-liquid chromatography (glc) and gas- liquid chromatography-mass spectrometry (GLc-ms) is described in this article.

TL;DR: The original synthesis of 6-deoxy-6-fluoro- D -glucopyranose has been improved and the preferred rotamer about the C-5-C-6 bond in 1,2,3,4-tetra-O-acetyl- 6- deoxy-six-fluoros-α- and -β- D-glucopsyl fluorides was identified as having F-6 and H-5 antiplanar.

TL;DR: In this paper, high-resolution n.m.r. spectroscopy was used to measure the conformational equilibria in chloroform-d solution for the tri- O -acetyl-D -aldopentopyranosyl bromides having the α- xylo ( 1), α- lyxo ( 3), β- ribo ( 5 ), and β- arabino ( 7 ) configurations, together with corresponding chlorides ( 2, 4, 6, and 8 ).

TL;DR: Zosterine isolated from various Zosteraceae species appeared to be a homogeneous, pectic polysaccharide containing D -galacturonic acid, D-galactose, L -arabinose, D -apiose, and a mono-O-methyl- D -xylose as components of its carbohydrate chain.

TL;DR: In this paper, the separation and structural analysis of 21 permethylated trisaccharides by gas-liquid chromatography (g.l.c.-m.s.) is described.

TL;DR: Two α-D -linked disaccharides, 6-O -α-D-glucopyranosyl- D -galactose and 3-O-α- D-GLU-D −Galactose, were synthesized by reaction of 2- O -benzyl-3,4,6-tri-O − p -nitrobenzoyl-α(or β- D −glucophyranosy bromide with 1,2:3, 4-di- O −isopropyl