title: Structure-antioxidant activity relationships of flavonoids isolated from the resinous exudate of Heliotropium sinuatum.
abstract: Relationships between the structural characteristics of flavonoids isolated from the resinous exudate of Heliotropium sinuatum and their antioxidant activity were studied. Radical formation energies, DeltaH of dehydrogenation and spin densities were calculated using DFT methods (B3LYP/6-31G*). Results show that studied flavonoids can be divided into two sets according to their activity. It has been found that antioxidant activity depends both on substitution pattern of hydroxyl groups of the flavonoid skeleton and the presence of an unsaturation at the C2-C3 bond. A good tendency between DeltaH of dehydrogenation and antioxidant activity was established.
authors.affiliation: Facultad de Química y Biología, Departamento de Ciencias del Ambiente, Universidad de Santiago de Chile, Casilla 307, Correo 2, Santiago, Chile. bmodak@lauca.usach.cl
authors.forename: Brenda
authors.initials: B
authors.lastname: Modak
authors.forename: M Leonor
authors.initials: ML
authors.lastname: Contreras
authors.forename: Fernando
authors.initials: F
authors.lastname: González-Nilo
authors.forename: René
authors.initials: R
authors.lastname: Torres
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D028162:Heliotropium / Q000737:chemistry*; D006865:Hydrogenation; D017665:Hydroxyl Radical / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D013329:Structure-Activity Relationship
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010936:Plant Extracts; D017665:Hydroxyl Radical