Binding of carbohydrates to solid supports Part 3: Reaction of sugar hydrazones with polystyrene substituted with aromatic aldehydes

The hydrazones of glucose and N-acetylglucosamine, as models for the residues at the reducing termini of glycans, were covalently and reversibly bound in good yield to hydroxybenzaldehydo ligands attached to a polymer support. The binding, by a sugar azine linkage, occurred within two hours at room temperature at neutral pH, and efficient recoveries of sugars from the beads were achieved by displacement with aqueous hydrazine hydrate, ethanolic benzaldehyde, or aqueous acetone. Enzyme modification of glycans was demonstrated by separation of the products of hydrolysis of lactose hydrazone with -galactosidase, using hydroxybenzaldehyde-derivatized polystyrene beads. Addition of a spacer arm to aminopolystyrene beads, for binding of reducing sugars as Amadori compounds to the aromatic amine function, was also investigated.