FOUR HELIANGOLIDES AND OTHER SESQUITERPENES FROM BRASILIA SICKII

Article abstract of DOI:10.1016/0031-9422(83)80224-6

The investigation of Brasilia sickii afforded, in addition to known compounds, two new bisabolene derivatives, an acetate closely related to damsinic acid together with its methyl ester, a dihydroxyaromadendrane, a thymol derivative and four heliangolides, closely related to a similar lactone isolated from a Calea species.The structures were elucidated by high field 1H NMR spectroscopy and a few chemical transformations, while the sructure of the spathulenol derivative was established by partial synthesis.The chemotaxonomy is discussed briefly. - Key Word Index: Brasilia sickii; Compositae; sesquiterpene lactones; heliangolides; sesquiterpenes; bisabolene derivatives; damsinic acid derivative; spathulenol derivative; thymol derivative; triterpene isovalerate.