Anti-inflammatory Lindenane Sesquiterpene Dimers from the Roots of .

In this study, eight lindenane-type sesquiterpene dimers, including five previously undescribed sesquiterpene dimers (-), were isolated from the roots of , and their structures were elucidated using 1D/2D NMR, HRESIMS, and ECD calculations. Compound presents the second example of a type of novel 8,9- lindenane-type sesquiterpene dimer, considered a product of 8/9-diketone oxidation. Compounds and represent the third and fourth examples, respectively, of this kind of C-11 methine dimer. Furthermore, compound was considered as an artifact generated from the radical reaction of a known compound chlojaponilide F (), which was explained by the density functional theory quantum calculation. All isolates were evaluated for their protective activity against the LPS-induced pulmonary epithelial cell line with compound exhibiting the most potent bioactivity. Further biological evaluation demonstrated that reduced the production of reactive oxygen species and interleukin-1β, further regulated by the expression of the NLRP3. These results show that compound exhibits therapeutic potential for lung inflammatory diseases.