The alkaloids of Echium plantagineum L

Abstract

Two new alkaloids, echiumine, C₂₀H₃₁O₆N, and echimidine, C₂₀H₃₁O₇N, have been isolated from Echium plantagineum L. Both have a retronecine nucleus esterified on the 7-hydroxyl group with angelic acid. The main esterifying acid of echiumine is trachelanthic acid and of echimidine is 2-methyl-2,3,4-trihydroxypentane-3-carboxylic acid, identical with the esterifying acid of heliosupine. The structure of heliosupine, a diastereoisomer of echimidine, has been confirmed.