THE ALKALOIDS OF SENECIO SPECIES: III. SENECIO INTEGERRIMUS, S. LONGILOBUS, S. SPARTIOIDES AND S. RIDELLII

Abstract

Senecionine is the main alkaloid of Senecio integerrimus, but a small amount of a new alkaloid, integerrimine (C₁₈H₂₅O₅N), was also found. S. longilobus contains longilobine (C₁₈H₂₃O₅N) and S. ridellii contains ridelliine (C₁₈H₂₃O₆N), both alkaloids being new. In addition to the main alkaloid of S. spartioides, which was identified as seneciphylline, a minor base, spartioidine (C₁₈H₂₃O₅N), apparently new, was obtained. Hydrolysis of the new alkaloids that were available in sufficient quantity for this purpose yielded, in all cases, retronecine and a new necic acid. A structural formula for senecic acid is proposed.It has been shown that chemical examination of Senecio spp. may be used as an aid to botanical classification.