Synthesis with Glycosynthases: Cello-Oligomers of Isofagomine and a Tetrahydrooxazine as Cellulase Inhibitors

Abstract

Isofagomine and a carbohydrate-like tetrahydrooxazine, as their N-benzyloxycarbonyl derivatives, have been subjected to a glycosynthase in the presence of α-D-glucopyranosyl fluoride as a glucosyl donor. In each case, after protecting group removal, a mixture of 1,4-β-linked di-, tri-, and tetra-'saccharides' was obtained. These novel oligosaccharide derivatives were tested as inhibitors of the endo-glycanase Cex from Cellulomonasfimi. Affinities increased progressively as additional D-glucosyl residues were incorporated, which is consistent with the known substrate specificity of this enzyme.