Investigation into the Presence of Pyrrolizidine Alkaloids in Eupatorium cannabinum by Means of Positive and Negative Ion Chemical Ionization GC-MS.
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Abstract
It is demonstrated that the combination of positive ion chemical ionization and negative ion chemical ionization GC-MS analyses of herb and root extracts of EUPATORIUM CANNABINUM L. offers a rapid, tentative structure elucidation of pyrrolizidine alkaloids (PAs). Compounds identified in aerial parts of E. CANNAHIMUM in this way are four echinatine isomers, like lycopsamine and intermedine, and a number of their beta-acetyl, beta-angelyl/tiglyl and beta-(iso)valeryl esters. PAs without a substituent at C-7 were tentatively identified as supinine and amabiline. In addition to a number of these alkaloids, some beta-(iso)butyryl, beta-angelyl/tiglyl, and beta-(iso)valeryl esters of supinine or amabiline were detected in subterranean parts of the plant. PAS with a saturated necine base like the three trachelanthamine isomers and some beta-anglyl/tiglyl esters could be detected in the root material only. A C-9-viridifloryl/trachelanthyl ester of a saturated amino-alcohol like turneforcidine and one of its beta-angelyl/tiglyl esters have also been found. The latter 2 compounds, the beta-(iso)butyryl, the beta-(iso)valeryl, and the beta-angelyl/tiglyl esters of supinine or amabiline and the beta-(iso)valeryl ester of an echinatine isomer have not been described in nature before.