Seven undescribed labdane diterpenoids, japonicones A-G, were isolated from the aerial parts of Leonurus japonicus Houtt. Japonicones C-G contained two keto carbonyl groups in their structures attached to C-3 and C-7, which are rare for labdane diterpenoids. The structures and absolute configurations of japonicones A-G were established by means of spectroscopic analyses (HRESIMS, 1D and 2D NMR, and ECD). Their anti-inflammatory activities were evaluated by measuring their inhibitory effects on PGE2 production in LPS-stimulated RAW264.7 macrophages. Japonicones A-D and G showed inhibition of PGE2 production with IC50 values in the range of 8.62-30.71 μM (the positive control paracetamol showed an IC50 = 5.79 μM).

中文翻译：

---

来自 Leonurus japonicus Houtt 的抗炎拉丹烷二萜

从 Leonurus japonicus Houtt 的地上部分分离出 7 种未描述的拉丹二萜类化合物 japonicones AG。Japonicones CG 在其与 C-3 和 C-7 相连的结构中含有两个酮羰基，这在劳丹烷二萜中很少见。japonicones AG 的结构和绝对构型是通过光谱分析（HRESIMS、1D 和 2D NMR 以及 ECD）建立的。通过测量它们对 LPS 刺激的 RAW264.7 巨噬细胞中 PGE2 产生的抑制作用来评估它们的抗炎活性。Japonicones AD 和 G 显示出抑制 PGE2 产生，IC50 值在 8.62-30.71 μM 范围内（阳性对照扑热息痛显示 IC50 = 5.79 μM）。