Linear and star‐shaped hybrid polymers, 3. An improved purification procedure for coupling products of oligosaccharides by amide linkage

Abstract A convenient method for binding saccharides to natural and synthetic substances, polymers and low molecular weight compounds, consists in coupling via an amide linkage. For this purpose aldonolactone or amino groups are introduced at the reducting end of the saccharides which allows coupling to a great variety of amino and carboxyl groups containing compounds. Purification with the usual ion‐exchange resins based on polystyrene proved unsatisfactory for oligosaccharides due to adsorption effects and reduced ion‐exchange capacity. Excellent results on each step of conversion are obtained by chromatography on a cross‐linked poly(acrylamide) gel (Bio‐Gel P‐4 and P‐10) containing a small amount of carboxylic groups introduced by moderate saponification. The new procedure combining the effect of molecular size fractionation and ion‐exchange chromatography offers a wide field of application.