New insights into the chemotaxonomic implications of diterpenoid alkaloid composition in Aconitum sessiliflorum

Through phytochemical research, the composition of diterpenoid alkaloids in Aconitum sessiliflorum was analyzed, and sixteen compounds were identified. Among them, there are seven napelline type C₂₀-diterpenoid alkaloids (1–4, 7–8, 15), three denudatine type C₂₀-diterpenoid alkaloids (5–6, 16), and six aconitine type C₁₉-diterpenoid alkaloids (9–14). On the basis of NMR spectroscopy, the structural analysis of the separated compounds was achieved by comparing with previous data. All sixteen compounds were isolated for the first time from the Aconitum sessiliflorum, of which five compounds (1, 6, 9, 13, 15) were isolated for the first time from series Brachypoda, where Aconitum sessiliflorum is classified. These diterpenoid alkaloids not only enrich the chemical diversity of Aconitum sessiliflorum, but also facilitate the analysis of their chemotaxonomic implications. Importantly, the diverse types and structural features of these diterpenoid alkaloids provide new insights into both the potential phylogenetic affiliations within the series Brachypoda and the varying degrees of evolutionary divergence among these related taxa.