Structure of lasiansine from Aconitumnagarum var. lasiandrum

A new C₁₉-diterpenoid alkaloid, lasiansine (1), was isolated from the roots of Aconitu nagarum var. lasiandrum (Ranunculaceae) together with six known diterpenoid alkaloids. The structure of 1 was elucidated by spectral methods (¹H-NMR, ¹³C-NMR, 2D-NMR, HRMS, IR), and the ¹³C-NMR spectrum of 16-epipyroaconine (3) and the single-crystal X-ray analysis of its derivative (5) are reported for the first time.