Synthesis and anti-influenza virus activity of novel glycopolymers having triantennary oligosaccharide branches

An efficient method for the synthesis of novel glycopolymers with triantennary sialooligosaccharides showing potent anti-influenza virus activity is described. Polymerisable glycoside of triantennary N-acetyllactosamine [beta-D-galactopyranosyl-(1-->4)-2-acetamido-2-deoxy-D-glucopyranose, Gal beta(1-->4)GlcNAc] is synthesised from lactose and 4-(3-hydroxypropyl)-4-nitroheptane-1,7-diol as key starting materials, and converted into water-soluble glycopolymers by radical copolymerisation with acrylamide. Subsequent enzymic sialylation using cytidine 5'-monophospho-N-acetylneuraminic acid (CMP-Neu5Ac) with alpha-2,3-sialyltransferase from porcine liver or with alpha-2,6-sialyltransferase from rat liver gives novel glycoprotein mimics having potent inhibitory activity against influenza virus infection. It is demonstrated that the present triantennary glycoligands exhibit much higher biological activities than the effects by glycopolymers derived from the simple monovalent-type glycomonomers.