In the search for sources of songorine, we studied Aconitum barbatum Pers. We did not find songorine in flowerheads and leaves of A. barbatum collected in Irkutsk Oblast′ during flowering but did isolate leucostinine A. Leucostinine A was first observed in 1996 by Chinese researchers in roots of A. leucostomum and in 1999 by Swiss scientists from flowers of A. lycoctonum (reported as a new base 6-O-acetyldemethylenedelcorine), meaning the same compound was given different names. Both groups established the structure using mass, PMR, and 13C NMR spectra (DEPT, COSY), but assignments for C-5, C-9 and C-10, and C-13 were interchanged. We used a heteronuclear method (1H—13C HMBC) to assign signals in the PMR and 13C NMR spectra of leucostinine A and confirmed that the Swiss researchers had interpreted the NMR spectra correctly. The chemical shift of the N atom was obtained from the 15N—1H HMBC spectrum (correlated with H-17, H-19, and ethyl CH3). Leucostinine A has the formula C27H43NO8, with mass spectrum (EI, 70 eV) showing m/z 509 ([M]+), 494 ([M - 15]+), 478 ([M - 31]+, 100%), 450 ([M - 60]+), 434 ([M - 15 - 60]+), and 15N NMR spectrum (40.5 MHz, CDCl3) showing δ 344.0 (CH3NO2 internal standard). PMR and 13C NMR data are given in Table 1. Flowerheads and leaves of A. barbatum (90 g) were extracted with CHCl3 after wetting with saturated Na2CO3 solution; the concentrated extract was treated with 5% H2SO4, neutralized to pH 9-10 with Na2CO3, and re-extracted with CHCl3 to get a base fraction (2.7 g, 3% of air-dried weight). This fraction was separated by column and flash chromatography over Al2O3 and silica gel (3% Na2CO3) with gradient elution (hexane:acetone, hexane:chloroform, chloroform:methanol) to afford leucostinine A (9 mg) as an amorphous colorless substance. Isolation of leucostinine A from A. barbatum is the third instance of its occurrence in the plant world.