Sczukinitines C - I, new C₂₀-diterpenoid alkaloids from Aconitum sczukinii

Seven undescribed C₂₀-diterpenoid alkaloids, sczukinitines C - I (1-7), along with twelve known alkaloids (8-19) were isolated from the roots of Aconitum sczukinii. Their structures were elucidated on the basis of extensive spectroscopic analysis, including IR, HRESIMS and NMR analyses. Among the seven new diterpenoid alkaloids, compound 1 is an atisine-type C₂₀-diterpenoid alkaloid, compound 2 is a hetisine-type C₂₀-diterpenoid alkaloid, and compounds 3-7 are hetidine-type C₂₀-diterpenoid alkaloids. All compounds were evaluated for inhibitory activity against Sf9 cell line. Notably, compounds 5 and 7 exhibited moderate inhibitory effects at 40 μM, with inhibition rates of 44.88 ± 3.14% and 37.34 ± 1.27%, respectively.