A Minor Diterpenoid with a New 6/5/7/3 Fused-Ring Skeleton from <i>Euphorbia micractina</i>

Abstract

A novel diterpenoid with an unprecedented 6/5/7/3 fused-ring skeleton, euphorbactin (1), was isolated from an ethanol extract of the roots of Euphorbia micractina. The structure was determined by extensive spectroscopic studies, especially by 2D NMR and CD data analysis. A proposed biosynthetic pathway and preliminary investigations of the biological activity of compound 1 are also discussed.