To identify new potential anti-influenza compounds, we isolated six flavonoids, 2′-hydroxyl yokovanol ( 1 ), 2′-hydroxyl neophellamuretin ( 2 ), yokovanol ( 3 ), swertisin ( 4 ), spinosin ( 5 ), and 7-methyl-apigenin-6-C-β-glucopyranosyl 2″- O -β- d -xylopyranoside ( 6 ) from MeOH extractions of Ohwia caudata . We screened these compounds for antiviral activity using green fluorescent protein (GFP)-expressing H1N1 (A/PR/8/34) influenza A-infected RAW 264.7 cells. Compounds 1 and 3 exhibited significant inhibitory effects against influenza A viral infection in co-treatment conditions. In addition, compounds 1 and 3 reduced viral protein levels, including M1, M2, HA, and neuraminidase (NA), and suppressed neuraminidase (NA) activity in RAW 264.7 cells. These findings demonstrated that 2′-hydroxyl yokovanol and yokovanol, isolated from O. caudate , inhibit influenza A virus by suppressing NA activity. The moderate inhibitory activities of these flavonoids against influenza A virus suggest that they may be developed as novel anti-influenza drugs in the future.
【저자키워드】 influenza A, flavonoid, neuraminidase,