Influenza A (H1N1) neuraminidase inhibitors from Vitis amurensis

Recently, a novel H1N1 influenza A virus (H1N1/09 virus) was identified and considered a strong candidate for a novel influenza pandemic. As part of an ongoing anti-influenza screening programme on natural products, eight oligostilbenes were isolated as active principles from the methanol extract of Vitis amurensis. This manuscript reports the isolation, structural elucidation, and anti-viral activities of eight compounds on various neuraminidases from influenza A/PR/8/34 (H1N1), novel swine-origin influenza A (H1N1), and oseltamivir-resistant novel H1N1 (H274Y) expressed in 293T cells. The inhibition model of compounds 4, 6, and 7 which showed the strongest activity on the neuraminidases was examined. Detailed kinetic analysis indicated that they were all non-competitive. The synergistic effect of a combination of these non-competitive inhibitors with oseltamivir makes them a potential possibility for the control of influenza infections.