Acetolysis polysaccharides

Formolysis and acetolysis are not common methods for cleavage of glycosidic linkages. They do have some unique applications, however. For instance, methylated polysaccharides are not generally soluble in hot water, and consequently, hydrolysis is best preceded by formolysis under these circumstances. For example, 5 mg of methylated polysaccharide is dissolved in 3 mL of 90% formic acid, and the solution is kept for 2 h at 100°. The formic acid is removed by evaporation at 40°. The residue is dissolved in 1 mL of 250 mM sulfuric acid and the solution is heated for 12 h at 100°, cooled, the acid neutralized with barium carbonate, the... 

Various techniques have been utilized for sequencing the glycosyl residues of polysaccharides and oligosaccharides. These techniques are elaborations of the commonplace procedure of converting polysaccharides, by partial hydrolysis, into structurally analyzable oligosaccharides. This conversion is generally achieved by partial hydrolysis with acid, by acetolysis,131 or by formolysis.62 These reagents may differ in the... 

A. J. Farrant, J. R. Nunn, and H. Parolis, Sulphated polysaccharides of the Grateloupiaceae family. Part VII. Investigation of the acetolysis products of a partially desulphated sample of the polysaccharide of Pachymenia carnosa, Carbohydr. Res., 25 (1972) 283-292. 

A. I. Usov and V. V. Barbakadze, Polysaccharides of algae. 27. Partial acetolysis of the sulfated galactan from the red seaweed Grateloupia divaricata Okam, Sow J. Bioorg. Chem., 4 (1978) 814-820(English translation from Bioorg. Khim., 4 (1978) 1107-1115). 

The great use of acetolysis in polysaccharide chemistry is in degradation of the polysaccharides, imder mild conditions, to oligosaccharide per-acetates. More-drastic conditions afford monosaccharide peracetates, including those of the aldehydo forms of the sugars. " The many oligosaccharides obtained from the partial acetolysis of various polysaccharides are excellently documented in a book by Bailey, and the reader searching for particular examples is referred thereto. 

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