Two new norditerpenoid alkaloids from Delphinium potaninii.

Further studies on the chemical constituents of Delphinium potaninii roots led to the isolation of two new lycoctonine-type norditerpenoid alkaloids, potanisines A (1) and B (3). The structures of these compounds were determined by interpretation of the spectroscopic data. They are the first examples of naturally occurring lycoctonine-type norditerpenoid alkaloids possessing an N-formyl moiety.