title: Defensive chemistry of Senecio miser.
abstract: Three eremophilanolides, 1alpha-acetoxy-8beta-methoxy-10betaH-eremophil-7(11)-en-8alpha,12-olide (1); 1alpha-angeloyloxy-6beta-hydroxy-8beta-methoxy-10betaH-eremophil-7(11)-en-8alpha,12-olide (2); and 1alpha-angeloyloxy-8betaH,10betaH-eremophil-7(11)-en-8alpha,12-olide (3), and two pyrrolizidine alkaloids, integerrimine (4) and its N-oxide (5), were isolated from bioactive fractions of Senecio miser. The structures of the new compounds 1 and 2 were established by NMR spectroscopic analysis and chemical transformation. The X-ray analysis of compound 1 was also performed. Eremophilanolides 1 and 2 and alkaloids 4 and 5 were found to be strong insect antifeedants, further supporting a proposed defensive role for these classes of compounds.
authors.affiliation: Instituto de Productos Naturales y Agrobiología (IPNA), CSIC, La Laguna, Tenerife, Spain. mreina@ipna.csic.es
authors.forename: M
authors.initials: M
authors.lastname: Reina
authors.forename: A
authors.initials: A
authors.lastname: González-Coloma
authors.forename: C
authors.initials: C
authors.lastname: Gutiérrez
authors.forename: R
authors.initials: R
authors.lastname: Cabrera
authors.forename: M L
authors.initials: ML
authors.lastname: Rodríguez
authors.forename: V
authors.initials: V
authors.lastname: Fajardo
authors.forename: L
authors.initials: L
authors.lastname: Villarroel
mesh_terms: D000818:Animals; D001042:Aphids; D002677:Chile; D001517:Coleoptera; D018360:Crystallography, X-Ray; D005247:Feeding Behavior / Q000187:drug effects; D005659:Fungicides, Industrial / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D005670:Fusarium / Q000187:drug effects; D006458:Hemolymph / Q000187:drug effects; D007306:Insecticides / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D009281:Naphthalenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology; D010947:Plants, Toxic; D000081223:Polycyclic Sesquiterpenes; D011763:Pyrrolizidine Alkaloids / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D012674:Senecio / Q000737:chemistry*; D012717:Sesquiterpenes; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D018411:Spodoptera
chemical_list: D005659:Fungicides, Industrial; D007306:Insecticides; D009281:Naphthalenes; D010936:Plant Extracts; D000081223:Polycyclic Sesquiterpenes; D011763:Pyrrolizidine Alkaloids; D012717:Sesquiterpenes; C018286:eremophilane compounds; C009237:senecionine