Glucosyl groups

Structure 34 was proposed for a trisaccharide composed of d-glucose, D-galactose, and 2-acetamido-2-deoxy-D-galactose residues. The D-glucosyl group and the D-galactosyl residues are the same as in disaccharide 32. That the 2-acetamido-2-deoxy-D-galactose residue is linked to 0-3 was indicated by color reactions and the fact that this... 

In this way Vongerichten restricted the carbohydrate (n-glucosyl) group to position 7 of apigenin it also followed that the apiose moiety is joined to the D-glucose component in a disaccharide union. 

A half-chair conformation of a crystalline monosaccharide has not been observed. A half-chair conformation for the fourth 2-acetamido-2-deoxy-/3-D-glucopyranosyl residue (residue D) in the lysozyme substrate has not been detected, although, on the basis of model fitting, its presence has been suggested (see p. 96). 2-Acetamido-2-deoxy-/3-D-glucosyl groups were added to a molecular model constructed by use of data obtained from the nature of the enzyme-trisaccharide complex it was implicit that the lifetime of the half-chair conformation would be quite short. 

Enzymic hydrolysis can often provide the means for solving a problem involving the partial hydrolysis of esters. A synthesis145 of 1-O-ab-scisoyl-/3-D-glucopyranose proved difficult at the last step, but the use of a crude enzyme-preparation obtained from ripe seeds of Helianthus annus allowed deacetylation to be achieved at 0-2, 3, 4, and 6 of the D-glucosyl group without rupture of the ester bond to the anomeric center. 

The lipopolysaccharide from Mycobacterium phlei contains glyceric acid, glycosidically linked to a D-glucosyl group as shown in 114. The glyceric acid was selectively removed by a Lossen rearrangement performed under very mild conditions by using a water-soluble carbodiimide (see Scheme 15).179... 

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