Oligosaccharides containing amino sugars

The oligosaccharides containing amino sugar residues have received considerable attention during the last few years, and numerous compounds of this type are now known (seeTable III). Degradation of certain polysaccha- 

Saccharides Containing Amino Sugar Residues Only 

Controlled degradation of chitin has been effected by the following sequence.261 The saccharide mixture may be separated by carbon-Celite 

Controlled fragmentation of chitin yields, in addition to di-A-acetylchito-biose, a range of saccharides containing j3-d-(1 — 4)-linked 2-acetamido-2-deoxy-D-glucose residues.261 

Saccharides Containing Residues of Amino Sugars and of Neutral, Nan-nitrogenous Sugars 

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Oxidation of 2-acetamido-2-deoxy-D-glucose derivatives with hypoiodite at 0° proceeds quantitatively, without side reactions, and is satisfactory as a procedure for end-group assay in oligosaccharides containing amino sugar residues.177 The possibility that (1 —> 3)-linked disaccharides may be degraded under the reaction conditions must not be overlooked. 

Whilst there appears to be limited scope at present for the utilization of these observations in determinations of polysaccharide structures, they can be of value when the Morgan-Elson test is applied to oligosaccharides containing amino sugar residues, as the work on the oligosaccharides from human milk2 has shown. Obviously, no simple relation exists between a positive test and the presence of free 2-acetamido-2-deoxyhexose, but much information may be culled by a consideration of all the factors outlined above. 

In a discussion of the use of deamination to obtain structural information, it is convenient to consider two different aspects (a) applications to monosaccharide and cyclitol amines, and (b) applications to compounds containing amino sugar and inosamine residues. The latter compounds would include oligosaccharides, polysaccharides, glycolipids, glycoproteins, and antibiotics. 

A mass-spectrometric investigation of the antibiotics Paromomycin and Paromomycin II as their per(trimethylsilyl) derivatives has been made. A molecular ion was found in these tetrasaccharides containing amino sugars. The A-series of fragments was found to establish the sequence of the monosaccharide residues in the oligosaccharide. Essentially the same technique was used in a study of antibiotics from Streptomyces fradiae these were found to be tetrasaccharides containing an amino-deoxycyditol residue. " ... 

Several disaccharides containing one residue of an amino sugar have been synthesized by definitive chemical methods in connection with the study of the oligosaccharides from human milk. Others have only been prepared, as noted, by degradation of natural oligosaccharides. 

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