Isolation of three new sesquiterpene lactones from the pericarps of Illicium majus.

Abstract

Three new sesquiterpene lactones, majucin (3), neomajucin (4), and 2, 3-dehydroneomajucin (5), have been isolated from the pericarps of Chineses Illicium majus, which is a toxic plant. The spectral features of compounds 3 and 4 were similar to those of anisatin (1), a convulsant from Japanese star anise. The structure of neomajucin (4) was determined by an X-ray crystallographic analysis, and the structures of the other compounds were deduced from the 1H- and 13C-nuclear magnetic resonance spectral data, aided by an extensive analysis of the 1H-1H, 13C-1H, and 13H-1H long-range two dimensional shift-correlated spectra, on the basis of the structure of neomajucin. Only neomajucin exhibited picrotoxin-like toxicity, amounting to one-tenth of that of anisatin.