A New Diterpenoid and a New Diterpenoid Alkaloid fromAconitum coreanum

A new diterpenoid, guan fu diterpenoid A (1), and a new diterpenoid alkaloid, guan fu base S (2), were isolated from the Chinese medicinal herb Aconitum coreanum (Levl.) Rapaics, together with five known diterpenoid alkaloids guan fu base P, guan fu base R, guan fu base G, guan fu base F, and guan fu base Z. The structures of the two new compounds were elucidated as ent-kaurane-16,20-diol (1) and (11β,13S)-2,3,15,16-tetradehydro-16,17-dihydrohetisan-11,13,14-triol 11,13-diacetate (2) on the basis of HR-MS and 2D-NMR analyses. This is the first report of an ent-kaurane diterpenoid in Aconitum coreanum.