Sesquiterpenoids from Chloranthus holostegius var. shimianensis: Structures and anti-inflammatory activities.

Seven previously undescribed sesquiterpenoids, designated as chloranholosins N‒T (1-7), including two acorane-type sesquiterpenoids (1-2), two lindenane-type sesquiterpenoids (3-4), and three eudesmane-type sesquiterpenoids (5-7), together with six known analogues (8-13) were isolated from the whole plants of Chloranthus holostegius var. Shimianensis. Their structures and absolute configurations were elucidated by a comprehensive method including the spectroscopic data, electronic circular dichroism calculations, and single-crystal X-ray diffraction. Compounds 5 and 6 are the first instances of eudesmane-type sesquiterpenoids with tigloyl and senecioyl substitutions at C-15, respectively. Additionally, the isolates were evaluated for their inhibitory activities against LPS induced nitric oxide production in RAW 264.7 macrophage cells. Among them, compounds 5 and 10 showed significant inhibitory activities with IC50 values of 9.35 ± 1.49 and 3.94 ± 0.69 μM, respectively. Compounds 1, 3, 4, 6, 9, and 12 showed moderate inhibitory activities with IC50 values from 10.48 to 35.36 μM, compared with that of the positive drug dexamethasone at 15.01 ± 1.33 μM.