Diterpenoids from Isodon melissoides.

Abstract Four new ent -kaurane diterpenoids, melissoidesin A-D, together with a known diterpenoid, gesneroidin C, were isolated from aerial parts of Isodon melissoides . Their structures were elucidated by spectral evidence. The new diterpenoids were identified as ent -1β,7α,11α-trihydroxy-3α,6β-diacetoxy-kaur-16-en-15-one; ent -1β,11α-dihydroxy-3α,6β,7α-triacetoxy-kaur-16-en-15-one; ent -1β,7α,11α,15α-tetrahydroxy-3α,6β-acetoxy-kaur-16-ene; and ent -1β,7α,11α-trihydroxy-3α,6β-diacetoxy-16α-ethoxymethyl-kaur-15-one.