In this study, the dried rhizomes of Atractylodes japonica Koidz. were extracted with MeOH, suspended with water, and continuously partitioned
with n-hexane, CHCl3, EtOAc, and n-BuOH. Fourteen compounds were isolated from the n-hexane and CHCl3 fractions using various chromatographic techniques. Chemical structures of twelve
compounds were characterized by spectroscopic methods as sesquiterpenes including
atractylenolide III (1), atractylenolide II (2), 8β-methoxyatractylenolide (3), 4,15-epoxy-8β-hydroxyasterolide (4), (3R)-3-hydroxyatractylenolide III (5), taenialactam B (6), 8-epiasterolide (7), eudesma-3,7(11)-dien-5,15-dihydroxy-8α,13-olide (8), 4(15)-eudesmene-1β,7,11-triol (9), 3-eudesmene-1β,7,11-triol (10), eudesm-7(11)-en-4-ol (11), and eudesm-4(15),7-diene-11-ol (12). The others were determined to be a polyacetylene and a steroid glycoside viz., atractylodiol
(13) and daucosterol (14). Compounds 8 and 12 are reported for the first time from nature, compounds 5, 6, 9, and 10 are newly reported from Compositae, compound 7 is newly reported from Atractylodes genus, and compounds 3, 4, and 11 are reported for the first time from A. japonica.
The inhibition on LPS-induced NO production of the isolated compounds were measured
using Griess assay in RAW264.7 cells. Among the compounds, compounds 2 and 10 showed higher activity in dose-dependent manner without cytotoxicity. Compound 2, not containing 8-hydroxy moiety, displayed higher inhibitory activity than compounds
1, 4, and 5 that contain the 8-hydroxy moiety.
