Design of N-acetyl-6-sulfo-β-d-glucosaminide-based inhibitors of influenza virus sialidase Original Research Article

Biological activity of N-acetyl-6-sulfo-β-d-glucosaminides (6-sulfo-GlcNAc 1) having a structural homology to N-acetylneuraminic acid (Neu5Ac 2) and 2-deoxy-2,3-dehydro-N-acetylneuraminic acid (Neu5Ac2en 3) was examined in terms of inhibitory activity against influenza virus sialidase (influenza, A/Memphis/1/71 H3N2). pNP 6-Sulfo-GlcNAc 1a was proved to show substantial activity to inhibit the virus sialidase (IC50=2.8 mM), though p-nitrophenyl (pNP) GlcNAc without 6-sulfo group and pNP 6-sulfo-GlcNH3+ 1b without 2-NHAc showed little activity (IC50 >50 mM). The activity was enhanced nearly 100-fold when the pNP group of 1a was converted to p-acetamidophenyl one 5 (IC50=30 μM) or replaced with 1-naphthyl 6 (IC50=10 μM) or n-propyl one 8 (IC50=11 μM).