Neo-clerodane diterpenoids from three species of Teucrium

Three species of the genus Teucrium have been investigated. Two of them (T. rivas-martinezii and T. divaricatum subsp. divaricatum) contain known neo-clerodane diterpenoids, and the other one (T. asiaticum) contains a new neo-clerodane derivative, teucrasiatin, together with another previously known diterpene. The structure of teucrasiatin [(12S,20S)-19-acetoxy-4 alpha,18;15,16-diepoxy-6-oxo-neo- cleroda-13(16),14-diene-20,12-hemiacetal] was established by chemical and spectroscopic means.