Synthesis of well-controlled glycopolymers bearing oligosaccharides and their interactions with influenza viruses

The synthesis of a series of glycopolymers bearing oligosaccharides using a 'post-click' chemistry strategy with an acrylamide (AAm) backbone was reported. The synthesized glycopolymers recognized the corresponding lectins, and poly(AAm-r-60-SALac) exhibited interactions with influenza viruses. AAm and trimethylsilyl propargyl acrylamide which has an alkyne moiety, were copolymerized by RAFT polymerization in dimethylsulfoxide. Several saccharides including two types of sialyllactoses were subjected to a one-step azidation reaction to afford the corresponding azide derivatives of the oligosaccharides without the need for a protection step. The terminals of the glycopolymer were reduced to thiol with NaBH₄. The reduced glycopolymers were subsequently immobilized onto the SiO₂-coated QCM cell surfaces. When the molar ratio of [TMS PrAAm] was greater than 20%, the percentage conversion values were less than 40%. Furthermore, an increase in the initial molar ratio of [TMS PrAAm] resulted in a decrease in the conversion. This result suggested that TMS PrAAm was an inappropriate substrate for radical polymerization reactions.