Carbohydrates glycosides, acetylated

Carbohydrates exhibit enormous diversity because of variation in monosaccharide composition, glycosidic linkage positions, and chain branching [17], Further diversity is achieved by covalent modification of carbohydrates via acetylation, methyl-ation, phosphorylation, and sulfation [1]. Sulfation can be incorporated into the carbohydrates of glycolipids and glycoproteins. Modifications of both A-linked and 0-linked chains are found. 

P212l21 Z = 4 DX = 1.475 R = 0.10 for 1,627 intensities. This molecule is a glycoside of cucurbitoein. The analysis was made for the determination of the configuration. The glycoside residue is that of a novel carbohydrate, 2-0-acetyl-6-deoxy-a-L-glucopyranosid-3-ulose. 

From the identification of these products it was possible to give a means of portraying the type of structure (LVIII) present in the carbohydrate molecule. In this, by glycosidic attachment, seven N-acetyl-D-glucosamine unitB and one D-galactose unit radiate from a central core of three D-mannose units. It is not yet clear by what linkages the d-mannose units are mutually attached, or to which D-mannose the d-galactose residue is linked. 

Formation of the three-dimensional network of bacterial peptidoglycan includes synthesis both of glycosidic and peptide linkages, but only the former type of reaction is discussed in this Section. The assembly of the carbohydrate chains of a peptidoglycan has been shown to occur through a block mechanism. The initial reaction consists in transfer of N-acetyl-muramyl-pentapeptide phosphate from the corresponding UDP derivative... 

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