Complete Assignments of NMR Spectral Data of Three C19-Diterpenoid Alkaloids

Abstract

C19-diterpenoid alkaloids have complex and diverse structures, posing great challenges for nuclear magnetic resonance (NMR)-based structural elucidation. Three C19-diterpenoid alkaloids, including taronenine E (1), chasmaconitine (2) and vilmorisine (3), were isolated from the roots of Aconitum taronense Fletcher et Lauener, and analyzed by various NMR spectroscopy methods (i.e., 1H and 13C NMR, DEPT, 1H-1H COSY, HSQC and HMBC). Complete assignments of the NMR chemical shifts were obtained, providing a good reference for the further research of C19-diterpenoid alkaloids.

Keywords

• C19-diterpenoid alkaloids
• Aconitum taronense Fletcher et Lauener
• nuclear magnetic resonance (NMR)
• assignment