Glycosyl-transferase catalyzed assemblage of sialyl-lewisx-saccharopeptides Original Research Article

A series of glycohexopyranuronic acids are coupled to glucosamines to give ‘disaccharides’ which have the natural N-acetyl group of the glcNAc-moiety replaced by various sugar acids (→saccharopeptides). These saccharopeptides are surprisingly good substrates for β(1-4)galactosyl-transferase, α(2-3)sialyl-transferase, and fucosyl-transferase VI. The enzymes transfer successively galactose, sialic acid, and fucose from the corresponding donors onto these acceptor substrates—despite the far reaching alterations—regio- and stereospecifically in the expected manner to yield a new class of compounds, the sialyl-Lewisx-saccharopeptides.