Structural investigations on polysaccharides

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" Structural investigations on polysaccharides "
M. C. G. Knebl

Document Type	:	Latin Dissertation
Language of Document	:	English
Record Number	:	1112394
Doc. No	:	TLpq303439722
Main Entry	:	M. C. G. Knebl
Title & Author	:	Structural investigations on polysaccharides\ M. C. G. Knebl
College	:	York University (Canada)
Date	:	1985
student score	:	1985
Degree	:	M.Sc.
Page No	:	88
Abstract	:	The first part of this thesis explores the possibility of using the Curtius Rearrangement for the selective cleavage of usd\betausd-D-glucosiduronic acid linkages in acetylated polysaccharides. The procedure involves the treatment of acetylated glucosiduronamides with lead tetraacetate, in the presence of tert-butanol, to furnish 5-tert-butyloxycarbonylaminopentopyranosides. Cleavage of glycosidic linkages in the structurally modified polysaccharide is effected by mild acid hydrolysis to give intermediate pentodialdoses and aglycones. Pentodialdoses derived from uronic acid residues are reduced to pentitols, with glycosyl substituents still attached. The sites of former attachment of hexuronic acid residues may be ascertained by further reactions of the exposed aglyconic hydroxyl groups. These reaction sequences have been performed on acetylated derivatives of usdDusd-galacturonic acid, gentiobiouronic acid and gum arabic. The objective of the second part of the thesis is to obtain structural information regarding the location of usd\alphausd-D-galactopyranose residues in the outer chains of gum arabic. The approach involves the use of coffee bean usd\alphausd-galactosidase to generate degraded gum arabic. Comparison of gum arabic (from Acacia senegal) and usd\alphausd-galactosidase degraded gum has provided new evidence for the location of these residues.
Subject	:	Biochemistry
	:	Pure sciences