Two new sesquiterpenoids (1 and 2) and a new ent-pimarane type diterpenoid (3), together with eighteen known compounds (4–21), were isolated from the whole plants of Siegesbeckia pubescens. The structures of the new compounds were determined on the basis of 1D-, 2D NMR and HRESIMS data. All compounds were evaluated for their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages. Of these, highly oxygenated germacrane type sesquiterpenoids (1–2 and 13–14) showed significant inhibitory effects with IC₅₀ values ranging from 3.9 to 16.8 μM.

中文翻译：

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从一氧化氮抑制成分豨毛

两个新的倍半萜（1和2）和一个新的ENT -pimarane型二萜（3）中，用18种已知化合物（一起4 - 21）中，从全植物中分离豨毛。根据1D-，2D NMR和HRESIMS数据确定了新化合物的结构。评估了所有化合物对RAW 264.7巨噬细胞中LPS诱导的一氧化氮生成的抑制作用。在这些中，高度氧化吉马烷型倍半萜（1 - 2和13 - 14）表现出显著抑制作用与IC ₅₀ 值范围从3.9到16.8μM。