Wildi E, Langer T, Schaffner W, Büter K B
Universität Basel, Institut für Pharmazie--Pharmazeutische Biologie, Witterswil, Switzerland.
Planta Med. 1998 Apr;64(3):264-7. doi: 10.1055/s-2006-957422.
Various locations in Switzerland were screened for Petasites hybridus plants with high petasin and low pyrrolizidine alkaloid content. The mean petasin content of the various populations ranged from 7.4 to 15.3 mg/g dry weight in rhizomes and from 3.3 to 11.4 mg/g dry weight in leaves. Mean pyrrolizidine alkaloid content in rhizomes ranged from 5 to 90 ppm whereas leaves contained between 0.02 to 1.50 ppm. These results suggest that leaves might be a preferable source for harvesting compared to the underground organ due to the finding of high petasin contents and consistently lower amounts of toxic pyrrolizidine alkaloids.
