Flavonoids from Matteuccia struthiopteris and Their Anti-influenza Virus (H1N1) Activity

Seven new flavonoid glycosides (1–7), matteflavosides A–G, together with 12 known flavonoids (8–19) were isolated from the rhizomes of Matteuccia struthiopteris (L.) Todar. Their structures were established via the analyses of extensive spectroscopic data. All compounds were evaluated for their anti-influenza virus (H1N1) activity using the neuraminidase inhibition assay. The results showed that compound 7 exhibited significant inhibitory activity against the H1N1 influenza virus neuraminidase with an EC50 value of 6.8 ± 1.1 μM and an SI value of 34.4, and compounds 8 and 17 showed moderate inhibitory activity.