Six new guaiane dimers, xyloplains A–F (1–6), with connecting patterns through two direct C–C bonds (C-1 to C-3′, C-2 to C-1′), were isolated from the roots of Xylopia vielana. Their structures were elucidated clearly using extensive analysis of 1D NMR and 2D NMR, combined with Cu-Kα X-ray diffraction and circular dichroism (CD) experiments. In additon, all of the isolates were tested for anti-inflammatory activity by measuring the amount of nitric oxide produced. To our delight, compounds 2 and 6 exhibited moderate inhibitory activity against the production of nitric oxide with IC₅₀ value of 34.5 and 31.1 μM, respectively, in RAW264.7 cells stimulated by LPS.

中文翻译：

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Xyloplains A–F，来自 Xylopia vielana 的六种新的愈创木醚型倍半萜二聚体†

从根中分离出六种新的愈创木二聚体，木原素 A-F ( 1-6 )，通过两个直接的 C-C 键（C-1 到 C-3'，C-2 到 C-1'）连接模式Xylopia vielana的。使用 1D NMR 和 2D NMR 的广泛分析，结合 Cu-Kα X 射线衍射和圆二色性 (CD) 实验，清楚地阐明了它们的结构。此外，通过测量产生的一氧化氮的量来测试所有分离物的抗炎活性。令我们高兴的是，在 LPS 刺激的 RAW264.7 细胞中，化合物2和6对一氧化氮的产生具有中等抑制活性，IC _{50值分别为 34.5 和 31.1 μM。}