title: The basic antioxidant structure for flavonoid derivatives.
abstract: An antioxidant structure-activity study is carried out in this work with ten flavonoid compounds using quantum chemistry calculations with the functional of density theory method. According to the geometry obtained by using the B3LYP/6-31G(d) method, the HOMO, ionization potential, stabilization energies, and spin density distribution showed that the flavonol is the more antioxidant nucleus. The spin density contribution is determinant for the stability of the free radical. The number of resonance structures is related to the π-type electron system. 3-hydroxyflavone is the basic antioxidant structure for the simplified flavonoids studied here. The electron abstraction is more favored in the molecules where ether group and 3-hydroxyl are present, nonetheless 2,3-double bond and carbonyl moiety are facultative.
authors.affiliation: Núcleo de Estudos e Seleção de Biomoléculas da Amazônia, Instituto de Ciências da Saúde, Universidade Federal do Pará, 66075-110, Belém, PA, Brazil.
authors.forename: Anna P S
authors.initials: AP
authors.lastname: Mendes
authors.forename: Rosivaldo S
authors.initials: RS
authors.lastname: Borges
authors.forename: Antonio M J Chaves
authors.initials: AM
authors.lastname: Neto
authors.forename: Luiz G M
authors.initials: LG
authors.lastname: de Macedo
authors.forename: Albérico B F
authors.initials: AB
authors.lastname: da Silva
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D002412:Cations; D005419:Flavonoids / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D008958:Models, Molecular; D013329:Structure-Activity Relationship
chemical_list: D000975:Antioxidants; D002412:Cations; D005419:Flavonoids; D005609:Free Radicals