Fukinotoxin, a new pyrrolizidine alkaloid from Petasites japonicus.

Abstract

Fukinotoxin (I), a novel pyrrolizidine alkaloid, was isolated from young scape of Petasites japonicus and its structure has been shown to be (12R, 13R, 15R, 3'R)-12-hydroxy-4, 12, 13-trimethyl-4, 8-secosenec-1-enine-15-spiro-2'-(3'-methyl) oxiran with the aid of chemical and X-ray crystallographic analyses.