Two new germacranolides from Magnolia grandiflora.

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, (+) medioresinol and 6,7-dimethoxycoumarin. The structures of the new compounds were elucidated on the basis of spectroscopic methods and X-ray diffraction.