Alkaloids of Delphinium corumbosum
SummaryFromDelphinium corumbosum Rgl. have been isolated methyllycaconitine, a new base which has been called delcorine, and a base with mp 93–95°C. On the basis of its chemical and spectral characteristics, a lycoctonine skeleton has been established for delcorine with α-hydroxy groups at C1 and C10, a β-hydroxy group at C6, a methylenedioxy group at C7 and C8, a β-methoxy group at C15, and a methoxy group at C19.
Three New C19-Diterpenoid Alkaloids from Delphinium Bonvalotii
Three new lycoctonine-type C19-diterpenoid alkaloids, bonvalotidine A, bonvalotidine B, and bonvalotidine C, along with sixteen known alkaloids, were isolated from the roots of Delphinium bonvalotii Franch. Their structures were established by spectral analysis and chemical methods.
SOME OXIDATION REACTIONS OF DELCOSINE
The alkaloid delcosine was oxidized by chromic acid in acetic acid, and also by the Oppenauer reaction, to dehydrodelcosine in which the carbonyl was shown by infrared absorption to be in a pentatomic ring. Oxidation of the alkaloid with silver oxide gave two products: (a) N-desethyldelcosine, which could be N-acetylated or converted back to the original base by ethylation, thus proving the presence of an N-ethyl group; (b) a compound, C24H37O7N, the properties of which agreed best with those of an internal ether, i.e., anhydrohydroxydelcosine. The action of N-bromosuccinimide on the alkaloid produced the same two compounds as silver oxide, plus a derivative, C22H33O7N, that proved to be N-desethyl-anhydrohydroxydelcosine. Potassium permanganate oxidized delcosine to a product, C22H31O7N, that had lost the N-ethyl group, contained the internal ether, and also a carbonyl in a five-membered ring. This same product was obtained on similar oxidation of N-desethyl-anhydrohydroxydelcosine. Oxidation of delcosin...