Scopariusic Acid, a New Meroditerpenoid with a Unique Cyclobutane Ring Isolated from Isodon scoparius.

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 1and 2, including their absolute configurations, were determined by spectroscopic methods, single-crystal X-ray diffraction analysis, and chemical methods. Compound 1showed weak cytotoxicity and moderate immunosuppressive activity. [ABSTRACT FROM AUTHOR]