Protecting-Group-Free Synthesis of Glycopolymers and Their Binding Assay with Lectin and Influenza Virus

Typical synthetic methods for glycopolymers are laborious and require multistep processes, including protection and deprotection steps. Here we describe a facile protecting-group-free synthetic approach to glycopolymers bearing oligosaccharides from free saccharides by direct azidation and click chemistry methods, followed by reversible addition-fragmentation chain transfer polymerization. This method can be applied not only to mono- and disaccharides, but also to large biologically relevant oligosaccharides having sialic acids. Due to the glycocluster effect, the glycopolymers strongly bind with the corresponding lectin and influenza A virus, as analyzed by the quartz crystal microbalance method and hemagglutination inhibition assay.