Analysis of pyrrolizidine alkaloid in Cacaliopsis nardosmia

CHED 521

Danielle S. Kelley, Blake M. Acton, Actonb@eou.edu, Samantha L. Savage, savages@eou.edu, Dane W. Erickson, and Ronald B. Kelley, ron.kelley@eou.edu. Department of Chemistry and Biochemistry, Eastern Oregon University, One University Boulevard, La Grande, OR 97850
As part of the continuing chemosystematic study of natural products from the plant family Asteraceae, pyrrolizidine alkaloids (PA's) are studied for their biological effects. Pyrrolizidine alkaloids, also known as senecio alkaloids, are potentially toxic secondary products and to be expected in relatives of the genus Senecio. Our investigation will focus on three different populations of Cacaliopsis nardosmia, located in Washington and Oregon. Preliminary GC-MS analysis of both the Washington and Oregon populations, and structural elucidation by means of NMR of the Oregon population has presented two different alkaloid chemotypes. The Oregon sample appears to be composed primarily of a novel retronecine monoester with miniscule amounts of the otonecine macrocyclic diesters, florosenine and otosenine. The Washington populations appear to be composed primarily of florosenine with trace amounts of otosenine. This is the first investigation into pyrrolizidine alkaloid content of this monotypic genus.