title: Antifungal activity of a new phenolic compound from capitulum of a head rot-resistant sunflower genotype.
abstract: In a previous study, we observed that bract and corolla extracts from a Sclerotinia sclerotiorum-resistant sunflower contained high amounts of the known coumarins scopoletin, scopolin, and ayapin. There was a correlation between coumarin concentration and disease resistance. Thin layer chromatography showed higher concentrations of three other compounds in the resistant genotype when compared to the susceptible. A bioassay-directed purification that used column chromatography and HPLC allowed the isolation of a new compound, 3-acetyl-4-acetoxyacetophenone, and known compounds, demethoxyencecalin and 3-acetyl-4-hydroxyacetophenone. Structures were assigned from spectral data, and bioactivities were characterized by in vitro bioassays against S. sclerotiorum. The new compound, 3-acetyl-4-acetoxyacetophenone, had an antifungal activity similar to the coumarin ayapin, previously described as a potent Sclerotinia inhibitor. The speed and simplicity by which these compounds can be detected make them suitable for use in screening procedures that may identify genotypes with valuable levels of resistance. A screening of seven sunflower genotypes in a field experiment showed a correlation between these compounds and resistance to Sclerotinia.
authors.affiliation: Grupo de Investigación Bioquímica Vegetal y Agrícola, Departamento de Bioquímica y Biología Molecular (ETSIAM), Universidad de Córdoba, Apdo. 3048, 14080 Cordoba, Spain. bb2prpee@uco.es
authors.forename: Elena
authors.initials: E
authors.lastname: Prats
authors.forename: Juan C
authors.initials: JC
authors.lastname: Galindo
authors.forename: Maria E
authors.initials: ME
authors.lastname: Bazzalo
authors.forename: Alberto
authors.initials: A
authors.lastname: León
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Macías
authors.forename: Diego
authors.initials: D
authors.lastname: Rubiales
authors.forename: Jesús V
authors.initials: JV
authors.lastname: Jorrín
mesh_terms: D000935:Antifungal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001203:Ascomycota / Q000187:drug effects*; D001681:Biological Assay; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004352:Drug Resistance, Microbial; D005838:Genotype; D006368:Helianthus / Q000235:genetics / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010636:Phenols / Q000302:isolation & purification / Q000494:pharmacology*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000935:Antifungal Agents; D010636:Phenols