title: Methyl angolensate changes in Khaya ivorensis after fungal infection.
abstract: Khaya ivorensis with and without symptoms of stem and branch cankers, caused by Botryosphaeria rhodina were examined in order to determine whether the secondary metabolites in this plant were associated with a chemical defense response. This study provides evidence that the limonoid methyl angolensate (MA) is present at higher concentrations in K. ivorensis with symptoms of stem cankers rather than in the plants without symptoms. A rapid, sensitive and selective HPLC-ESI-MS/MS method (using selected reaction monitoring--SRM--mode) was developed for quantification of MA in all aerials parts of such plants, with a good linearity over a range of 0.1-20.0 g/kg, with r(2)>0.996+/-6.1%. The limits of detection (LOD) and quantification (LOQ) were less than 0.03 g/kg and 0.08 g/kg, respectively. Relative Standard Deviations (RSDs) ranged from 1.7% to 19.2% for all matrices. While the MA concentration did not change in the stem bark, its amounts increased nearly fourfold in stems and by 20% in leaves, when plants with symptoms were compared with those without symptoms. These data suggest that MA plays a role in plant-pathogen interactions, probably as a phytoanticipin.
authors.affiliation: Laboratório de Produtos Naturais, Departamento de Química, UFSCar. Rodovia Washington Luiz, Km 235, Postcode 676, CEP 13565-905, São Carlos, São Paulo, Brazil.
authors.forename: Karine V G
authors.initials: KV
authors.lastname: Reche
authors.forename: Gezimar D
authors.initials: GD
authors.lastname: de Souza
authors.forename: Marília A
authors.initials: MA
authors.lastname: Trapp
authors.forename: Edson
authors.initials: E
authors.lastname: Rodrigues-Filho
authors.forename: Sebastião C
authors.initials: SC
authors.lastname: Silva
authors.forename: João B
authors.initials: JB
authors.lastname: Fernandes
authors.forename: Paulo C
authors.initials: PC
authors.lastname: Vieira
authors.forename: Manfred W
authors.initials: MW
authors.lastname: Muller
authors.forename: M Fátima das G F
authors.initials: MF
authors.lastname: da Silva
mesh_terms: D005658:Fungi / Q000472:pathogenicity*; D054884:Host-Pathogen Interactions; D029582:Meliaceae / Q000378:metabolism* / Q000382:microbiology; D010935:Plant Diseases; D018514:Plant Structures; D014315:Triterpenes / Q000378:metabolism*
chemical_list: D014315:Triterpenes; C092741:methyl angolensate