Five previously undescribed labdane diterpenoids, named Forsypensins A-E, were isolated from the fruits of Forsythia suspensa. The structures and relative configurations of the compounds were elucidated via extensive spectroscopic methods, and their absolute configurations were fully confirmed by single crystal X-ray diffraction analyses using Cu Kα radiation and electronic circular dichroism data. The five labdane diterpenoids showed in vitro anti-inflammatory activity in rat polymorphonuclear leukocytes, inhibiting the rates of β-glucuronidase release by 43.6%-49.2% at concentrations of 10 μM. The compounds also had anti-viral activity against influenza A (H1N1) virus and respiratory syncytial virus (RSV), with IC50 values in the range 21.8-27.4 μM, and EC50 values in the range 10.5-15.4 μM, respectively.

中文翻译：

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来自连翘的 Labdane 二萜类化合物，具有抗炎和抗病毒活性

从 Forsythia suspensa 的果实中分离出五种以前未描述的拉丹二萜类化合物，名为 Forsypensins AE。通过广泛的光谱方法阐明了化合物的结构和相对构型，并通过使用 Cu Kα 辐射和电子圆二色性数据的单晶 X 射线衍射分析完全证实了它们的绝对构型。五种拉丹烷二萜类化合物在大鼠多形核白细胞中显示出体外抗炎活性，在 10 μM 的浓度下抑制 β-葡萄糖醛酸酶释放速率 43.6%-49.2%。这些化合物还对甲型流感 (H1N1) 病毒和呼吸道合胞病毒 (RSV) 具有抗病毒活性，IC50 值分别在 21.8-27.4 μM 范围内，EC50 值分别在 10.5-15.4 μM 范围内。