Sugar Amino Acid

The sugar amino acid 1 is a glycoamino acid in which N-acetyl-D-glucosamine is linked to the asparagine by an N-glycosidic linkage, and can be used for the synthesis of asparagine linked glycoproteins or glycopeptides. For instance, when 1 is reacted with a peptide supported on silica gel, followed by transglycosylation with galactose or sialic acid using glycosyltransferase, its oligosaccharides can be elongated.²⁾ Moreover, this glycoamino acid is also used for the “Chemo-Enzymatic Method”, by which the complex glycopeptide 4 is synthesized by ransglycosylation of an oligosaccharide of the natural N-linked glycopeptide 3 to an N-acetyl-D-glucosamine moiety of the glycopeptide 2, using Endo-M.³⁾