title: Cerium(IV)-mediated oxidation of flavonol with relevance to flavonol 2,4-dioxygenase. Direct evidence for spin delocalization in the flavonoxy radical.
abstract: The cerium(IV)-mediated oxidation of 3-hydroxy-4'-methylflavone (1) proceeds by H-atom abstraction forming the flavonoxy radical (7), and the subsequent combination of its resonance forms leads to the 3-hydroxy-4'-methylflavone dehydro dimer (9). The above system serves as direct evidence for the intermediacy of the flavonoxy radical, its spin delocalization, and also indirect evidence for valence tautomerism as a key step on the substrate activation both in the quercetinase and its biomimic model system.
authors.affiliation: Department of Organic Chemistry, University of Pannonia, 8201 Veszprém, Hungary.
authors.forename: József
authors.initials: J
authors.lastname: Kaizer
authors.forename: Ildikó
authors.initials: I
authors.lastname: Ganszky
authors.forename: Gábor
authors.initials: G
authors.lastname: Speier
authors.forename: Antal
authors.initials: A
authors.lastname: Rockenbauer
authors.forename: László
authors.initials: L
authors.lastname: Korecz
authors.forename: Michel
authors.initials: M
authors.lastname: Giorgi
authors.forename: Marius
authors.initials: M
authors.lastname: Réglier
authors.forename: Serge
authors.initials: S
authors.lastname: Antonczak
mesh_terms: D002563:Cerium / Q000737:chemistry*; D018360:Crystallography, X-Ray; D049308:Dioxygenases / Q000737:chemistry*; D044948:Flavonols / Q000737:chemistry*; D008958:Models, Molecular; D010084:Oxidation-Reduction; D013113:Spin Labels
chemical_list: D044948:Flavonols; D013113:Spin Labels; D002563:Cerium; D049308:Dioxygenases; C121201:flavonol 2,4-dioxygenase