Chemoenzymatic synthesis of glycoconjugate polymers starting from nonreducing disaccharides

Here we report the chemoenzymatic synthesis and recognition function of glycoconjugate polymers carrying nonreducing disaccharides [α-D- glucopyranosyl-(1-1)-α-D-glucopyranoside (trehalose) and α-D-galactopyranosyl-(1-1)-α-D-glucopyranoside (Gal-type trehalose)]. The lipase-catalyzed esterification of the disaccharides with divinyl sebacate is completely selective at the primary Glc 6-OH position of trehalose and at the Gal 6-OH position of Gal-type trehalose. The resultant vinyl esters can be polymerized to yield glycoconjugate polymers with poly(vinyl alcohol) backbones. The interactions of the glycoconjugate polymers with lectins (concanavalin A and Bandeiraera simplicifolia) are amplified because of the glycocluster effect. The polymer carrying pendant α-D- galactopyranosyl-(1-1)-α-D-glucopyranoside shows inhibition activity against Shiga toxin-1 based on a stereochemical structure similar to that of globosyl Gb2 disaccharide.