Sesquiterpene lactones and other constituents of Disynaphia multicrenulata from Argentina

Flowers and leaves of Disynaphia multocrenulata from Argentina afforded a large number of known germacradienolides and heliangolides, a new germacradienolide, a known melampolide, a new parthenolide derivative, one known and seven new cronquistiolides, a new 4Z-melampolide. three known and five new eudesmanolides. a new elemadienolide, a known grazielolide, an isoguaiagrazielolide. two diepoxygermacran-8,12-olides, three common kauranoic acids, pinoresinol, jaceosidin and the sesquiterprne oplopanone. Structures were elucidated by high-field H-1 NMR spectrometry. The relationship to the known chemistry of other members of the Disynaphiinae is discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.