Unprecedented 4/7 Bicyclic Carbon Skeleton Sesquiterpenoids With Anti-Inflammatory Activities Isolated From the Root of Lindera glauca.

Six new sesquiterpenoids glasesquiterpenoids A-F (1-6), together with two known ones, 7 and 8, were coisolated from the root of Lindera glauca. Their structures were elucidated by x-ray diffraction, quantum chemical calculations, and spectroscopic methods. Glasesquiterpenoid A (1) with an unprecedented 4/7 bicyclic carbon skeleton was the first example reported in the class of sesquiterpenoids. In the bioassays, compounds 6‒8 exhibited good inhibitory activity of NO production with IC50 values of 2.4, 5.5, and 4.0 µM, respectively, comparable to the positive control indomethacin (IC50 = 24.1 µM).