Chalcones as novel influenza A (H1N1) neuraminidase inhibitors from Glycyrrhiza inflata.
The emergence of highly pathogenic influenza A virus strains, such as the new H1N1 swine influenza (novel influenza) represents a serious threat to global human health. During our course of an anti influenza screening program on natural products, one new licochalcone G (1) and seven known (2 8) chalcones were isolated as active principles from the acetone extract of Glycyrrhiza inflata. Compounds 3 and 6 without prenyl group showed strong inhibitory effects on various neuraminidases from influenza viral strains, H1N1, H9N2, novel H1N1 (WT) and oseltamivir resistant novel H1N1 (H274Y) expressed in 293T cells. In addition, the efficacy of oseltamivir with the presence of compound 3 (5 mM) was increased against H274Y neuraminidase. This evidence of synergistic effect makes this inhibitor to have a potential possibility for control of pandemic infection by oseltamivir resistant influenza virus.
Bioorganic medicinal chemistry letters