title: Antioxidant and Free Radical Scavenging Activity of Phenolics from Bidens humilis.
abstract: A bioassay-oriented approach led to the isolation of 11 compounds, including three new natural flavonoids, (2S)-isookanin 7-O-α-L-arabinopyranoside (1), (2S)-isookanin 7-O-(2''-acetyl)-α-L-arabinopyranoside (2), and luteolin 7-O-β-D-glucopyranosyl-(1 → 6)-β-D-galactopyranoside (6), from Bidens humilis aerial parts. Their structures were determined via spectroscopic analyses including two-dimensional nuclear magnetic resonance. The antioxidant activity of all compounds was also tested by three different assays. The Relative Antioxidant Capacity Index (RACI) is applied herein, from the perspective of statistics, by integrating the antioxidant capacity data determined by these chemical methods.
authors.affiliation: Dipartimento di Farmacia, Università di Pisa, Pisa, Italy.
authors.forename: Mariela Beatriz
authors.initials: MB
authors.lastname: Vera Saltos
authors.affiliation: Departamento de Ciencias de la Vida, Universidad de las Fuerzas Armadas, ESPE, Sangolqui, Ecuador.
authors.forename: Blanca Fabiola
authors.initials: BF
authors.lastname: Naranjo Puente
authors.affiliation: Dipartimento di Scienze, Università degli Studi della Basilicata, Potenza, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Milella
authors.affiliation: Dipartimento di Farmacia, Università di Salerno, Salerno, Italy.
authors.forename: Nunziatina
authors.initials: N
authors.lastname: De Tommasi
authors.affiliation: Dipartimento di Farmacia, Università di Salerno, Salerno, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Dal Piaz
authors.affiliation: Dipartimento di Farmacia, Università di Pisa, Pisa, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Braca
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D031176:Bidens / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry / Q000378:metabolism*; D016166:Free Radical Scavengers / Q000737:chemistry / Q000378:metabolism*; D005609:Free Radicals / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry / Q000378:metabolism*; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D016166:Free Radical Scavengers; D005609:Free Radicals; D010636:Phenols; D010936:Plant Extracts