Lignans and a stilbene from Festuca argentina

A new (−)-epi-(4-hydroxyphenyl guaiacyl) tetrahydrofurofuran lignan, (1S,2S,5S,6R)-2-(4-hydroxyphenyl)-6-(3-methoxy-4-hydroxyphenyl)-3,7-dioxabicyclo[3.3.0]octane, as well as the rare (−)-pinoresinol, (−)-pinoresinol 4-O-β-d-glucopyranoside, (+)-medioresinol 4-O-β-d-glucopyranoside, and the known trans-resveratrol have been isolated from whole plants of Festuca argentina. The structures of these compounds have been established on the basis of chemical and spectral data. Complete 1H and 13C NMR assignments for the rare lignans were deduced.