Synthesis of 2-acetamido-2-deoxy-3-O-β-d-galactopyrano-syl-d-galactose by the sequential use of β-d-galactosidases from bovine testes and escherichia coli
β-d-Galp-(1→3)-d-GalNAc (1) was synthesised from lactose and GalNAc on a mmolar scale by transgalactosylation using β-d-galactosidase from bovine testes. The large proportions of unwanted oligosaccharides in the product mixture were removed by treatment with β-d-galactosidase from E. coli, which left 1, monosaccharides, and a small proportion of trisaccharides. Carbon-Celite chromatography then ga