Hawker Resources, Inc.

8-Methoxycarbonyloctyl-O-(α-D-galactopyranosyl)-(1→3)-(β-D-galactopyranosyl)-(1→4)-β-D-glucopyranoside, linked to a solid support can be used to remove Clostridium difficile toxin A from the intestinal tract.Therefore, multi-gram chem. and enzymic synthesis of the toxin binding trisaccharide from 8-methoxycarbonyloctyl β-lactoside disaccharide were explored.Chem. conversion in 30% overall yield could be achieved in seven steps.Alternatively a single step enzymic conversion of the lactoside using recombinant α(1→3)-galactosyltransferase with UDP-galactose or UDP-glucose/UDP-Glc epimerase gave the desired trisaccharide in 85-90% yield.