A new type of artificial glycoconjugate polymer: A convenient synthesis and its interaction with lectins

A convenient synthetic route to a new type of artificial glycoconjugate polymer has been designed to develop biomedical materials using oligosaccharide moieties as recognition signals. An amino function was introduced to the reducing end of lactose and N,N'-diacetylchitobiose with ammonium hydrogen carbonate and then was allowed to react with p-vinylbenzoyl chloride. The N-glycosidation proceeded stereospecifically in one flask to give only the beta-glycoside without any protection and deprotection steps; The resulting p-vinylbenzamide glycoside derivatives were homo- and copolymerized with acrylamide using 2,2'-azobisisobutyronitrile as initiator in dimethyl sulfoxide at 60 degrees C. The interaction of the glycopolymers with lectins was investigated by means of a two-dimensional immunodiffusion test in agar and inhibition of the hemagglutinating activity. The specificity of lectins with these glycopolymers was similar to that reported for naturally-occurring glycoconjugates. Binding between wheat germ agglutinin lectin (WGA) and poly((p-vinylbenzamido)-beta-diacetylchitobiose) was increased by 10(3) times compared with that of the oligosaccharide itself. The enhancement was attributed to the presence of the hydrophobic phenyl aglycon as well as the high density, multiantennary disaccharide ligands along the polymer chain. The present synthetic method is useful to introduce biologically important, complex oligosaccharides into glycopolymers.