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.