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.