Two novel diterpenoid alkaloids, grandiflodines A and B (1 and 2), were isolated from Delphinium grandiflorum. Compound 1 represents a rare hetisine-type C20-diterpenoid alkaloid in which the bond between the atoms of N and C-17 is broken. Compound 2 features an unusual lycoctonine-type C19-diterpenoid alkaloid skeleton with the cleavage of N–C19 and C7–C17 bonds, and the construction of the N–C7 bond. Structural elucidations of the isolates were performed by spectroscopic analysis, X-ray diffraction and comparison with the literature. These compounds were tested for their antiviral and anti-inflammatory activities.
