Antinociceptive C-diterpenoid alkaloids from the roots of .

Three new C-diterpenoid alkaloids, nagarumines A-C (), together two known alkaloids, deoxyaconitine () and N-deethyldeoxyaconitine (), were isolated from the roots of . The structures of the new compounds were elucidated by spectral methods such as 1D and 2D (H-H COSY, HMQC, and HMBC) NMR spectroscopy, as well as high resolution mass spectrometry. The pharmacological studies revealed that nagarumine C () possessed comparable antinociceptive activity (ED = 76.0 μmol/kg) with the positive control drugs aspirin and acetaminophen.