Eight previously undescribed diterpenoids of different types were isolated from ethyl acetate extract of the aerial parts of Euphorbia antiquorum L., along with fifteen known diterpenoids. Their structures and configurations were determined by 1D and 2D NMR, MS, and electronic circular dichroism (ECD). Additionally, the absolute configuration of ent-12-oxo-2,3-secobeyer-15-en-2,3-dioic acid-3-methyl ester was confirmed through single-crystal X-ray diffraction. Efficacy of the compounds on lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production in murine macrophage J774.A1 cells was evaluated. ent-15-Acetoxylabda-8(17),13E-diene-3-one, ent-15-oxolabda-8(17),13E-diene-3-one and rhizophorin B was significantly suppressed NO production with IC50 values of 11.7, 12.5 and 16.1 μM, respectively.

中文翻译：

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大戟地上部分的二萜类化合物及其对一氧化氮的抑制作用

从 Euphorbia antiquorum L. 地上部分的乙酸乙酯提取物中分离出 8 种以前未描述的不同类型的二萜，以及 15 种已知的二萜。它们的结构和构型由一维和二维核磁共振、质谱和电子圆二色性 (ECD) 确定。此外，通过单晶 X 射线衍射证实了 ent-12-oxo-2,3-secobeyer-15-en-2,3-dioic acid-3-methyl 酯的绝对构型。评估了化合物对小鼠巨噬细胞 J774.A1 细胞中脂多糖 (LPS) 刺激的一氧化氮 (NO) 产生的功效。ent-15-Acetoxylabda-8(17),13E-diene-3-one, ent-15-oxolabda-8(17),13E-diene-3-one 和 rhizophorin B 显着抑制 NO 的产生，IC50 值为 11.7 ，分别为 12.5 和 16.1 μM。