Structurally diversified sesquiterpenoids from Chloranthus henryi and their neuroprotective activities on HO damaged PC12 cells.

Fifteen undescribed sesquiterpenoid monomers, including six pairs of sesquiterpenoid enantiomers (1a/1b-3a/3b and 5a/5b-7a/7b) and three analogues (4, 8, and 9), together with two known sesquiterpenoid dimers (10 and 11) were isolated from the whole plant of Chloranthus henryi Hemsl. Their structures were characterized by spectroscopic data analysis, ECD calculations, and single crystal X-Ray diffractions. Compounds 1a and 1b were highly aromatic cadinane-type sesquiterpenoids. At a concentration of 10 μM, compounds 8, 10, and 11 exhibited potent neuroprotective activity against HO-induced PC12 cell damage. Compounds 10 and 11 significantly decreased the level of ROS. In addition, compound 11 increased the levels of p-AMPK, p-SIRT1, and SIRT3 in the HO-induced PC12 cell damage via activated the AMPK/SIRT signaling pathway.