Tadzhaconine — A new C-20 diterpene alkaloid from Aconitum zeravschanicum

Diterpenoid Alkaloids from the Lateral Root of Aconitum carmichaelii

“…In addition, irradiation of H-6 enhanced the H-5 and H 3 -18 resonances, while irradiation of H-11 enhanced the H-9, H-12, and H-15a resonances, indicating these protons were oriented on the other side of the ring system. The coupling constants J 1,2 (2.5 Hz), J 9,11 (9.0 Hz), and J 13,14 (9.0 Hz) were consistent with those of tadzhacotine, the 19-dehydroxy analogue of 1 isolated from Aconitum zwravschanicun , and its structure was determined by X-ray crystallographic analysis. These data suggested that 1 had the same configuration as tadzhacotine, with a 19β-OH group.…”

“…20 and was confirmed by the 2D NMR and NOE difference data for 20. Thus, compound 20 was defined as (−)-(A-b)-14α-benzoyloxy-N-ethyl-6α,8β,15α-trihydroxy- 1α,16β,18-trimethoxyaconitane.…”

“…However; the connection between C-5 and C-6 was indicated by HMBC correlations of H-6/C-10 and H 2 -7/C-5, while the connection between C-11 and C-12 was indicated by HMBC correlations of H-9/C-11, C-12; H-11/C-13, C-16; H-12/C-9, C-11, C-13, C-14; and H-13/C-11. The above information revealed the hetisan skeleton in 1 . Furthermore, the HMBC spectrum showed correlations of H-1 and H-11 with the carbonyl carbons of the two acetoxy groups and a correlation of H-2 with the carbonyl carbon of the benzoyl moiety, indicating that the acetoxy groups were present at C-1 and C-11 and the benzoyloxy group at C-2 in 1 .…”