title: Bioactive constituents of Conyza albida.
abstract: The bioactivity-guided fractionation of an active chloroform extract of Conyza albida led to the isolation of three alkenynes, deca-4,6-diyn-2-(Z)-enoic methyl ester (1), deca-4,6-diyn-2-(Z)-enoic ethyl ester (2) and deca-2,4-diene-4-hydroxy-6-yn-1,4-olide (3), and the terpenoid spathulenol (4), as the active toxic metabolites in the Artemia sp. lethality test. When tested in the KB cell cytotoxicity assay, compounds 1-4 demonstrated IC50 values of 52.2, 38.4, 117.9, and 83.8 microM, respectively. All compounds studied were inactive in the DNA methyl green and DNA strand scission assays, while compounds 3 and 4 showed moderate activity as inhibitors of human topoisomerase I. Compound 2 is reported here for the first time.
authors.affiliation: Departamento de Química Orgánica, Facultad de Ciencias Químicas U.N.C., IMBIV-CONICET, Pabellón de Ciencias II, Ciudad Universitaria, Córdoba, Argentina.
authors.forename: A V
authors.initials: AV
authors.lastname: Pacciaroni
authors.forename: E
authors.initials: E
authors.lastname: Mongelli
authors.forename: L
authors.initials: L
authors.lastname: Ariza Espinar
authors.forename: A
authors.initials: A
authors.lastname: Romano
authors.forename: G
authors.initials: G
authors.lastname: Ciccia
authors.forename: G L
authors.initials: GL
authors.lastname: Silva
mesh_terms: D019659:Asteraceae / Q000737:chemistry*; D006801:Humans; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D013057:Spectrum Analysis
chemical_list: D010936:Plant Extracts