The First Phytochemical Investigation of Artemisia divaricate: Sesquiterpenes and Their Anti-Inflammatory Activity

Artemisia divaricate belongs to the Artemisia genus of the family of Compositae, a sort of perennial herb endemic in most regions of China. For the first time, a phytochemical investigation was carried out on the whole plant of Artemisia divaricate, resulting in the identification of 39 sesquiterpenes, with 9 of them being new (1–9). The structures of the new compounds were fully established using extensive analysis of MS and 1D and 2D NMR spectroscopic data and density functional theory (DFT) NMR calculations. Their structures involve germacrane, eudesmane, and bisabolane types. All the new isolates were evaluated for their anti-inflammatory activities in lipopolysaccharide (LPS)-stimulated murine macrophages of RAW 264.7 cells. Compounds 2 and 8 showed a significant inhibition effect on NO production, with IC50 values of 5.35 ± 0.75 and 7.68 ± 0.54 µM, respectively.