Sesquiterpene lactones from Picris hieracioides L. var. japonica Regel. I.

Abstract

Three new sesquiterpene glycosides, picrisides A (III), B (VI) and C (VII), in addition to lactucin (I), 11β, 13-dihydrolactucin (II), crepidiaside A (IV) and ixerin F (V), have been isolated from the methanol extract of Picris hieracioides L. var. japonica REGEL (Compositae). The stuctures of the new compounds were determined on the basis of chemical and spectral data.