Steroidal glycosides, homoisoflavanones and cinnamic acid derivatives from Polygonatum odoratum and their inhibitory effects against influenza A virus

A phytochemical investigation of Polygonatum odoratum roots led to the isolation of fifteen steroidal glycosides (1–15), three homoisoflavanones (16–18) and four cinnamic acid derivatives (19–22). The structures of all isolated compounds were established mainly by spectroscopic analyses as well as necessary chemical evidence, of which 1–8 (polygodorasides A-G) were identified as new steroidal glycosides. Among the isolates, compounds 7 and 17 showed remarkable in vitro inhibitory effects against influenza A virus with IC50 values of 14.30 and 49.70 μM (positive control ribavirin 28.4 μM).