Anti-Inflammatory Lindenane Sesquiterpenoid Dimers from the Roots of Sarcandra glabra

Sarglaroids A-H ( 1 – 8 ), eight new lindenane dimers, and a monomer sarglaroid I ( 9 ), along with fourteen known analogues ( 10 – 23 ), were isolated from the roots of Sarcandra glabra . The planar structures and the absolute configurations were elucidated by HR-MS, NMR, ECD calculations, and X-ray diffraction crystallography. Sarglaroid A ( 1 ) was identified as a rare 8,9- seco lindenane dimer with a unique 5/5/5 tricyclic system. The biological evaluation showed that compounds 1 and 13 potently inhibited NO production with IC 50 values at 19.8 ± 1.06 and 10.7 ± 0.25 μM, respectively, and had no cytotoxicity to RAW264.7 cells. Compound 6 significantly inhibited the LPS-/ATP-induced IL-1β release by inactivating the NLRP3 inflammasome through inhibiting the initiation and assembly by affecting the K + efflux. Compounds 2 and 3 inhibited the proliferation of MCF-7 and MDA-MB-231 with IC 50 values ranging from 5.4 to 10.2 μM.