Five new eremophilane sesquiterpenes from Ligularia przewalskii

Five new eremophilane-type sesquiterpenes, 3 beta-(acetyloxy)-7-hydroxynoreremophila-6,9-dien-8-one (1), 8 beta-hydroxy-2-dehydroxyliguhodgsonal (2), 3 beta-(acetyloxy)-11-methoxy-8-oxoeremophila-6,9-dien-12-oic acid (3), 3 beta-(acetyloxy)-11-(2'-methylbutanoyloxy)-8-oxoeremophila-6,9-dien-12-oic acid (4), and 3 beta-(acetyloxy)-6 alpha-hydroxyligularenolide (5), along with the three known compounds 6 - 8, were isolated from the roots of Ligularia przewalskii. The structures of the new compounds were elucidated through spectral studies including HR-EI-MS, IR, and NMR data.