Abstract:From the roots of Delphinium gyalanum Marq. et Shaw native to China, a pair of new regioisomeric diterpenoid alkaloids as a mixture, named gyalanine A and B, was isolated whose structures were shown to be 4 and 5, respectively, on the basis of spectral data. The known diterpenoid alkaloids, delsemine A(1) and B(2), methyllycaconitine (3) and lycoctonine, were also obtained.