PYRROLIZIDINE ALKALOID CHEMOSYSTEMATICS IN AMSINCKIA

The distribution and quantitation of pyrrolizidine alkaloids (PAs) within the genus Amsinckia, Boraginaceae, was established by GC-mass spectrometric techniques. Twenty-eight PAs were structurally characterized from 55 samples representing 12 of the 14 known species. GC-mass spectrometric information, including R(I) values, is provided for these compounds as well as for 14 structurally related PAs. The chemosystematic significance of these results suggest that PAs can be used to distinguish sectional differences that are accompanied by chromosomal rearrangements, but not specific differences. The sectional placement of A. grandiflora is clarified supporting a proposed reinstatement of section Vernicosae, sens. str., and reducing the number of species belonging to section Tessellatae, sens. str., to three.