Scopariusicide C, a novel cyclobutene-containing meroditerpenoid from artificially cultivated Isodon scoparius

Abstract

Scopariusicide C (1), a novel ent-clerodane-based meroditerpenoid was isolated from artificially cultivated Isodon scoparius. An oxygen insertion reaction proposed to occur in its biosynthesis makes its scaffold different from those meroterpenoids previously isolated from the same species. The structure of 1 was determined by analysis of spectroscopic data, quantum chemical calculations and use of residual dipolar coupling (RDC). 1 showed moderate inhibitory effects against T and B lymphocyte proliferation and good anti-MRSA activity.