Scopariusic Acid, a New Meroditerpenoid with a Unique Cyclobutane Ring Isolated from <i>Isodon scoparius</i>

Scopariusic acid (1), a new ent-clerodane-based meroditerpenoid with a unique cyclobutane ring and an unusual 1-octen-3-ol substituent, together with its biosynthetic related compound 2, were isolated from the aerial parts of Isodon scoparius. The structures of 1 and 2, including their absolute configurations, were determined by spectroscopic methods, single-crystal X-ray diffraction analysis, and chemical methods. Compound 1 showed weak cytotoxicity and moderate immunosuppressive activity.从帚状香茶菜（Isodon scoparius）的地上部分中分离得到了一种新型基于对映-克罗烷的杂二萜类化合物scopariusic酸（1），其含有独特的环丁烷环与罕见的1-辛烯-3-醇取代基，同时还分离得到了与其生物合成相关的化合物2。通过波谱学方法、单晶X射线衍射分析以及化学手段，确定了化合物1和2的结构，包括其绝对构型。化合物1表现出微弱的细胞毒性与中等强度的免疫抑制活性。