Inflammatory Inhibitory Activity of Sesquiterpenoids from Atractylodes macrocephala Rhizomes.

Three new sesquiterpenoids, 13-hydroxyl-atractylenolide II (1), 4-ketone-atractylenolide III (2), and eudesm-4(15)-ene-7β,11-diol (3), along with eleven known compounds (4-14), were isolated from the rhizomes of Atractylodes macrocephala. The structures and relative configurations of 1-3 were determined by analysis of the spectroscopic data, and the absolute configurations of 1 and 2 were assigned by circular dichroism technique. The anti-inflammatory activities of these isolates were evaluated against lipopolysaccharide-induced nitric oxide production in macrophage RAW264.7 cells; compounds 4, 7, and 8 exhibited moderate efficacy with IC50 values of 48.6±0.5, 46.4±3.2, and 32.3±2.9 µM, respectively.