Synthetic potential of fucosyltransferase III for the synthesis of fluorescent-labeled milk oligosaccharides

Various fundamental biologic roles of milk oligosaccharides have been recognized; however, their structure-affinity relationship is still not fully revealed. Herein, we describe the synthesis of the fluorescent-labeled milk oligosaccharides 3-(5-dimethylaminonaphthalene-1-sulfonylamino)propyl β-D-galactopyranosyl-(1 → 3)-[α-L-fucopyranosyl-(1 → 4)]-2-acetamido-2-deoxy-β-D-glucopyranoside (1) and 3-(5- dimethylaminonaphthalene-1-sulfonylamino)propyl β-D-galactopyranosyl-(1 → 3)-[α-L-fucopyranosyl-(1 → 4)]-β-D-glucopyranoside (2) as useful tools for synthetic, analytic, and biologic applications. For the fucosylation of lactose and lacto-N-biose, the chemical and the enzymatic syntheses using fucosyltransferase III were compared.