title: Antioxidant and free radical-scavenging activity of constituents from two Scorzonera species.
abstract: The aim of this study was to investigate the secondary metabolites content of Scorzonera papposa DC., an edible plant eaten in the desert region of Jordan and to assess its antioxidant and free radical-scavenging activity. By using this bioassay-oriented approach nine compounds, including the new natural compounds (6-trans-p-coumaroyl)-3-O-β-D-glucopyranosyl-2-deoxy-D-riburonic acid (1), (6-cis-p-coumaroyl)-3-O-β-D-glucopyranosyl-2-deoxy-D-riburonic acid (2a), (6-trans-p-coumaroyl)-3-O-β-D-glucopyranosyl-2-deoxy-D-riburonic acid methyl ester (3), and (6-trans-p-coumaroyl)-3-O-β-D-glucopyranosyl-(5-acetyl)-2-deoxy-D-riburonic acid (4), having the rare deoxy-D-riburonic acid moiety, were isolated. Their structures were elucidated by UV, MS, (1)H and (13)C NMR and 2D NMR. The antioxidant activity of the S. papposa pure compounds and of related derivatives isolated from another Scorzonera species (S. judaica Eig.) was also tested. The Relative Antioxidant Capacity Index (RACI) was applied as an integrated method to compare the antioxidant activities obtained using different chemical methods.
authors.affiliation: Dipartimento di Scienze, Università degli Studi della Basilicata, Viale dell'Ateneo Lucano 10, 85100 Potenza, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Milella
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Umm Al-Qura University, P.O. Box 13174, 21955 Makkah, Saudi Arabia.
authors.forename: Ammar
authors.initials: A
authors.lastname: Bader
authors.affiliation: Dipartimento di Farmacia, Università di Salerno, via Giovanni Paolo II 132, 84084 Fisciano, Italy. Electronic address: detommasi@unisa.it.
authors.forename: Nunziatina
authors.initials: N
authors.lastname: De Tommasi
authors.affiliation: Dipartimento di Scienze, Università degli Studi della Basilicata, Viale dell'Ateneo Lucano 10, 85100 Potenza, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Russo
authors.affiliation: Dipartimento di Farmacia, Università di Pisa, via Bonanno 33, 56126 Pisa, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Braca
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry*; D031186:Scorzonera / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D005609:Free Radicals; D010936:Plant Extracts
keywords: Antioxidant activity; Glycosides; Scorzonera judaica Eig.; Scorzonera papposa DC.