Saccharides, acyl reduction

In order to study the reactivity of the nitrogen atom in saccharidic OZT moieties Rollin and co-workers13,55 explored some standard reactions IV-acylation, IV-sulfonylation, IV-vinylsulfonylation by Michael addition, reductive elimination, conjugated addition and cycloaddition. 

Polypeptide. The release of phosphogalactomannan, mannose, mannobiose and mannotriose from the polymer by alkali suggests that these saccharides are attached to a polypeptide (11). The amino acid composition of a peptidophosphogalactomannan preparation was determined (Table III). This table shows that approximately one-half of the amino acyl residues of the polypeptide are either seryl or threonyl residues and that the polypeptide has no aromatic or sulfur-containing amino acids. Treatment of the pol3nner with alkali followed by reduction of the a,3-dehydroamino-acyl residues formed resulted in a loss of all but 2 of the seryl residues and essentially all of the threonyl residues (Table IV). Furthermore, the number of alanyl residues increased from 4 to 8 and 4 residues of a-aminobutyric acid were obtained. These were derived from the reduction products of the a,3-dehydroserine (a-aminoacrylic acid) and a,3-dehydrothreonine (a-aminocrotonic acid), respectively, following 3-elimination of saccharides from seryl... 

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