germacranolide/モクレン属

Six components have been isolated from the bark of Michelia rajaniana, and their structures have been determined by spectroscopic analysis. Four of the components have been reported previously: The germacranolide (-)-parthenolide and the oxoaporphinoid alkaloid liriodenine have been observed as

Two new sesquiterpenoids, 4,5-epoxy-13-methoxy-1(10)-germacren-12,6-olide and 4,5-epoxy-13-acetoxy-1(10)-germacren-12,6-olide, were isolated from the leaves of Magnolia grandiflora, together with six known compounds, 2alpha-hydroxy-dihydroparthenolide, parthenolide, costunolide, syringaresinol, (+)

A new (3) and three known germacrane-type sesquiterpenoids were isolated from the chloroform-soluble fraction of the methanolic extract of the bark of Magnolia kobus (Magnoliaceae) through repeated silica gel and Sephadex LH-20 column chromatography. Their chemical structures were elucidated as

The germacranolide sesquiterpene lactones costunolide, parthenolide, and costunolide diepoxide were isolated from the leaves of Magnolia grandiflora L. Costunolide diepoxide might be, at least in part, an artifact derived from air oxidation of parthenolide. The root bark yielded only costunolide