title: Evaluation of Antioxidant Activity, Total Flavonoids, Tannins and Phenolic Compounds in Psychotria Leaf Extracts.
abstract: The antioxidant activity of Psychotria carthagenensis, P. leiocarpa, P. capillacea and P. deflexa (Rubiaceae) extracts were investigated, and the concentrations of total phenolics, flavonoids, condensed tannins and flavonols were determined. The chemical compositions of the extracts were investigated using the high performance liquid chromatography (HPLC/PAD) method. We used 1,1-diphenyl-1-picrylhydrazyl free radical (DPPH), β-Carotene bleaching and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cations to determine antioxidant activity. The ability to scavenge radical was measured in these experiments by the discoloration of the solution. Concentrations of constituents were measured spectrophotometrically. P. carthagenensis and P. capillacea exhibited the highest antioxidant activity, in the DPPH test, β-carotene bleaching and ABTS system. The highest phenolic, flavonoid, condensed tannin and flavonol concentration was found in P. carthagenensis and P. capillacea extracts. HPLC-PDA analysis of P. carthagenensis and P. capillacea revealed hydroxycinnamic acid (p-coumaric acid). This is the first report on the antioxidant properties and constituent analysis of these Psychotria extracts.
authors.affiliation: Faculty of Agricultural Sciences, University Federal of Grande Dourados (UFGD), 79804-970/533 Dourados-MS, Brazil. aneliseformagio@ufgd.edu.br.
authors.forename: Anelise Samara Nazari
authors.initials: AS
authors.lastname: Formagio
authors.affiliation: Biological and Environmental Sciences, University Federal of Grande Dourados (UFGD), 79804-970/533 Dourados-MS, Brazil. volobuff81@gmail.com.
authors.forename: Carla Roberta Ferreira
authors.initials: CR
authors.lastname: Volobuff
authors.affiliation: Biological and Environmental Sciences, University Federal of Grande Dourados (UFGD), 79804-970/533 Dourados-MS, Brazil. matheus_ss@hotmail.com.
authors.forename: Matheus
authors.initials: M
authors.lastname: Santiago
authors.affiliation: Chemistry Program, State University of Mato Grosso do Sul (UEMS), Mato Grosso do Sul, 79804-970/351 Dourados-MS, Brazil. claudia@uems.br.
authors.forename: Claudia Andrea Lima
authors.initials: CA
authors.lastname: Cardoso
authors.affiliation: Faculty of Agricultural Sciences, University Federal of Grande Dourados (UFGD), 79804-970/533 Dourados-MS, Brazil. mariavieira@ufgd.edu.br.
authors.forename: Maria do Carmo
authors.initials: Mdo C
authors.lastname: Vieira
authors.affiliation: Biological and Environmental Sciences, University Federal of Grande Dourados (UFGD), 79804-970/533 Dourados-MS, Brazil. zefapereira@ufgd.edu.br.
authors.forename: Zefa
authors.initials: Z
authors.lastname: Valdevina Pereira
keywords: Psychotria; antioxidant activity; p-coumaric acid