Isolation and identification of a new benzofuranone derivative from Usnea longissima

A new benzofuranone derivative, ethyl 2-(3,3-bis(7-acetyl-4,6-dihydroxy-3,5-dimethylbenzofuran-2-yl)acryloyl) (1), together with seven known compounds (2–8), was isolated from Usnea longissima. Their structures were elucidated by using spectroscopic methods, including 1D and 2D NMR experiments, UV, IR, EI-MS and HR-ESI-MS analysis.