Two novel C-nor-B-homo aconane-type diterpenes 4 and 5, featuring a unique eight-membered ring system, were obtained by the treatment of C-nor-C19-diterpenoid alkaloid 3 with HNO2 in 8% and 21% yields, respectively. Structures of these two compounds were established based on the combination of spectroscopic data, including HRESIMS, 1D and 2D NMR data. A olausible mechanism for the formation of 4 and 5 is also presented.
Xiang Li ShenQiao Hong ChenDong Lin ChenFeng Peng Wang
Three new C20-diterpenoid alkaloids, designated as anthriscifolmines A-C （1-3）, together with two known alkaloids denudatine and delgramine, were isolated from the whole herb of Delphinium anthriscifolium var. savatieri. The structures of these new alkaloids were elucidated on the basis of spectral data.
