Chemical constituents from <i>Atractylodes japonica</i> and their inhibitory effect on NO production

A new sesquiterpenoid, 7<i>β</i>-hydroxy-cnid-4(15),11(13)-dien-8-one (<b>1</b>) and a new polyacetylene, (4<i>E</i>,6<i>Z</i>,12<i>E</i>)-tetradecatriene-8,10-diyn-1-yl acetate (<b>2</b>), along with twenty known analogs (<b>3</b>-<b>22</b>), were obtained from <i>Atractylodes japonica</i>. Their chemical structures were established by spectroscopic techniques. All the isolates were evaluated for their inhibitory activity against NO production in LPS-induced RAW 264.7 cells, and compounds <b>2</b>-<b>7</b>, <b>9</b>-<b>16</b>, <b>18</b>-<b>22</b> exhibited inhibitory activities with IC₅₀ values ranging from 2.39 ± 0.54 to 46.51 ± 0.87 μM.