Two new diterpenoids, ajudecunoid A (1) and ajudecunoid B (14), along with thirteen known diterpenoids, were isolated from the whole plants of Ajuga nipponensis Makino. Their structures were elucidated by the extensive spectroscopic analysis (UV, IR, MS, and NMR). The absolute configurations of ajudecunoid A (1) and ajudecunoid B (14) were defined through analysis of X‐ray crystallography. Fifteen compounds were evaluated for inhibition of the formation of osteoclasts in bone marrow‐derived macrophages (BMM) cells. Two neo‐clerodane diterpenoids ajuganipponin B (5) and (12S)‐6α,19‐diacetoxy‐18‐chloro‐4α‐hydroxy‐12‐tigloyloxy‐neo‐clerod‐13‐en‐15,16‐olide (12) showed significant inhibition of osteoclastogenesis with IC50 values of 0.88 and 0.79 μM, respectively. Here we firstly reported diterpenoids with anti‐osteoclastogenesis activity from A. nipponensis.

中文翻译：

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Ajuga decumbens 全株中的二萜类化合物及其对 RANKL 诱导的骨细胞生成的抑制作用

从 Ajuga nipponensis Makino 的整个植物中分离出两种新的二萜类化合物，ajudecunoid A (1) 和 ajudecunoid B (14)，以及 13 种已知的二萜类化合物。通过广泛的光谱分析（UV、IR、MS 和 NMR）阐明了它们的结构。通过 X 射线晶体学分析定义了 ajudecunoid A (1) 和 ajudecunoid B (14) 的绝对构型。评估了 15 种化合物对骨髓源性巨噬细胞 (BMM) 细胞中破骨细胞形成的抑制作用。两种新克罗丹二萜类化合物 ajuganipponin B (5) 和 (12S)-6α,19-diacetoxy-18-chloro-4α-hydroxy-12-tigloyloxy-neo-clerod-13-en-15,16-olide (12)显着抑制破骨细胞生成，IC50 值分别为 0.88 和 0.79 μM。在这里，我们首先报道了来自 A. 具有抗破骨细胞生成活性的二萜类化合物。