Vinyl-Olefines and Sesquiterpenes in the Root-Oil of Senecio isatideus

Abstract

A series of polyunsaturated vinyl-hydrocarbons (n-C15 to n-C17) (10, 11, 12, 15, 16 and 17) including the as yet unknown all-cis-1,7,10,13-hexadecatetraene (15) as well as some rare sesquiterpenes such as isocomene (8) or modhephene (7) have been isolated from the root oil of Senecio isatideus. Unambigous positioning of the double bonds of the polyolefines was easily established by 13C-NMR spectroscopy [16]. A new mass spectroscopical method utilizing NO as a reactant gas for chemical ionization [1] made possible the reliable identification of minor and trace constituents without any chemical pretreatment or further derivatisation.