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.从香茶菜（Isodon scoparius）的地上部分中分离得到了香茶菜酸（Scopariusic acid，1）——一种兼具独特环丁烷环与罕见1-辛烯-3-醇取代基的新型对映-克罗烷型杂二萜（ent-clerodane-based meroditerpenoid），以及其生物合成相关化合物2。通过波谱学方法、单晶X射线衍射分析与化学手段，确定了化合物1与2的结构及其绝对构型。化合物1展现出微弱的细胞毒性与中等强度的免疫抑制活性。