GERMACRANOLIDES, A GUAIANOLIDE WITH A β-LACTONE RING AND FURTHER CONSTITUENTS FROM GRAZIELIA SPECIES

Article abstract of DOI:10.1016/0031-9422(81)83029-4

An investigation of three Grazielia species afforded, in addition to known compounds, several new sesquiterpene lactones, eight germacranolides, two melampolides and one guaianolide as well as three diterpenes, two geranylgeraniol derivatives and a labda-diene.Three of the sesquiterpene lactones had an additional β-lactone ring, one an acid function, and two others unusual ester functions.The structures were elucidated by spectroscopic methods and some chemical transformations.The chemotaxonomic situation is discussed briefly.Key Word Index- Grazielia intermedia; G. dimorpholepsis; G. serreta; Compositae; Eupatorieae; sesquiterpene lactones; germacranolides; guaianolides; melampolides; β-lactones; diterpenes.