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Of methylated sugars

Several methylated sugars have been identified in hydrolyzates of LPS, cell-wall polysaccharides, and extracellular polysaccharides. A considerable number of these have been found in the LPS from photosynthetic prokaryotes. Two polysaccharides from Mycobacterium species, a glucan" and a mannan" are remarkable in that they contain high percentages of methylated sugars. Glycolipids from Mycobacterium species are also rich in methylated sugars, some of which have not been found elsewhere, but this is beyond the scope of the present article. [Pg.300]

The present article is concerned with the use of gas-liquid chromatography for neutral, basic, and acidic sugars and some of their simple derivatives. A succeeding article will treat the separation of methylated sugars and their derivatives. [Pg.13]

Demethylation of methylated sugars by means of hydrogen peroxide in the presence of ferrous ions (the Fenton reagent) has been re-... [Pg.44]

In later years much important work was carried out in the St. Andrews laboratories on anhydro-sugars and their derivatives (G. J. Robertson) and on the nitrate esters of methylated sugars (J. W. H. Oldham). Irvine never diminished his keen interest in this work but it was inevitable that less time could be devoted to chemical research after he had assumed the onerous duties of Principal and Vice-Chancellor in 1921. It was characteristic of him, however, that only a few days before his death he was busy propounding long-term schemes of research on possible developments of sugar derivatives for use in chemotherapy. [Pg.428]

Oxidation of methylated sugars with nitric acid was used extensively by early workers for locating the position of unsubstituted hydroxyl groups.116 Cleavage of carbon-carbon bonds appears to be facilitated by the presence of such catalysts as vanadium salts. As hot nitric acid acts as a hydrolyzing agent as well as an oxidant, oligo- and poly-saccharides may be used directly. [Pg.341]

Preliminary examinations of dextran structures were conducted by optical rotation, infrared spectroscopy and periodate-oxidation reactions. More detailed results can be achieved by methylation analysis [19]. The hydroxyl groups are methylated with methyl iodide after activation with sodium methylsulfinyl carbanion (Fig. 2). The methyl dextran is hydrolysed to the corresponding different methylated monosaccharides, which are furthermore reduced and peracetylated. The resulting alditol acetates of methylated sugars are separated by gas chromatography and identified by their retention times. In particular, a combined capillary gas-liquid chromatography/mass... [Pg.205]

The Colorimetric Determination of Methylated Sugars An Improved Micromethod of End-group Assay, J. K. Bartlett, L. Hough, and J. K. N. Jones, Chem. Ind. (London),... [Pg.15]

Since the fractionation of methylated sugars by paper chromatography, column chromatography, and paper electrophoresis, as well as the properties of the methyl ethers of common sugars and their most suitable derivatives, have been described in previous Volumes of this Series and elsewhere, only a few special points and some recent advances will be discussed here. [Pg.66]

Mixtures of methylated sugars are generally fractionated by partition chromatography on cellulose columns. Lemieux and coworkers have found that columns of diatomaceous earth (for example, Celite) are as good as, or better than, cellulose columns for these separations. [Pg.67]

Chitotriose, periodate oxidation of, 385 —, tri-AT-acetyl-, 382, 384 Chlorogenic acid, 259 Chromatography, of methylated sugars, 66, 67... [Pg.420]

Before attention is directed to the preparation of other oxidation products, the extensive use of bromine oxidation in the field of methylated sugars should be noted. The oxidation of the various sugars pre-... [Pg.145]

The main limitation of the use of partially methylated alditol acetates for the characterization of methylated sugars lies in the structural symmetry that may exist when the primary hydroxyl group (0-5 in pentoses and 0-6 in hexoses) is not etherified. This difficulty, however, can be overcome by introducing deuterium at C-1 by reduction of the sugar with sodium borodeuteride. [Pg.346]

A limitation of zone electrophoresis in the field of methylated sugars is the non-reaction of several polymethylated derivatives with borate ions, but, as the results in Table II testify, in the mono- and di-O-methyl series there is a much wider variation in Ma values than in Ro values. [Pg.93]


See other pages where Of methylated sugars is mentioned: [Pg.254]    [Pg.181]    [Pg.45]    [Pg.478]    [Pg.324]    [Pg.325]    [Pg.342]    [Pg.13]    [Pg.14]    [Pg.17]    [Pg.23]    [Pg.53]    [Pg.66]    [Pg.345]    [Pg.71]    [Pg.82]    [Pg.159]    [Pg.345]    [Pg.511]    [Pg.92]    [Pg.281]    [Pg.114]   
See also in sourсe #XX -- [ Pg.342 ]

See also in sourсe #XX -- [ Pg.88 ]




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Demethylation, of methylated sugars

Glycosides methyl, of the common sugars

Jeanloz, Roger W., The Methyl Ethers of 2-Amino-2-deoxy Sugars

Methyl ethers of 2-amino-2-deoxy sugars

Methylation of sugars

Methylation of sugars

Of partially methylated sugars

Permethylated Sample, and Analysis of the Partially Methylated Sugars

Separation of methylated sugars

Sugar methylation

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