A lignan and a lignan derivative from the fruit of Forsythia suspensa

Abstract The chemical investigation of a 95% ethanol extract of the fruit of Forsythia suspensa resulted in the isolation of one new lignan and one new lignan derivative, forsythialan E-F, along with two known lignans. Their structures were established based on extensive spectroscopic data analyses, including UV, IR, HRESIMS, 1D NMR and 2D NMR. Absolute configurations of 1 - 2 were determined by the CD method. In addition, compounds 1 - 2 were evaluated for their antiviral activity against the influenza A (H5N1) virus in vitro.