Diterpenoid alkaloids from Aconitum liaotungenses

Four new diterpenoid alkaloids, namely liaotungenses A-D, along with twenty known constituents, were isolated from the roots of Aconitum liaotungense Nakai (Ranunculaceae). Liaotungensines A and B are rare franchetine-type C₁₉-diterpenoid alkaloids characterized by their unique dual hydroxylation pattern at C-13 and C-15. Liaotungense D is identified as the third documented example of 8,15-seco diterpenoid alkaloids in this structural class. Structural characterization was achieved through integrated spectroscopic analysis employing IR, HR-ESI-MS, and comprehensive 1D/2D NMR techniques. All isolated compounds underwent evaluation for anti-inflammatory potential via nitric oxide (NO) production inhibition assays, but none demonstrated marked inhibitory activity in this pharmacological assessment.