[Studies on the constituents of Scutellaria species. XV. On the diterpenoid constituents of the leaves of Scutellaria alpina L].

From the leaves of Scutellaria alpina L., four new neo-clerodane diterpenes (1-4) were isolated. The structures of 1-4 were shown to be (4S)-19-acetoxy-8 beta-hydroxy-6 alpha-benzoyloxy-4,18-epoxy-neo-cleroda-11,13- dien-15,16-olide, (4S)-19-acetoxy-8 beta-hydroxy-6 alpha-tigloyloxy-4,18-epoxy-neo-cleroda-11,13- dien-15,16-olide, (4S, 11S)-11-acetoxy-8 beta,19-dihydroxy-6 alpha-tigloyloxy-4,18-epoxy-neo- clerod-13-en-15,16-olide, and (4S)-19-acetoxy-8 beta-hydroxy-6 alpha, 7 beta-dibenzoyloxy-4,18-epoxy-neo- cleroda-11,13-dien-15,16-olide, respectively, by the chemical and spectral data.