title: Electrochemical and spectrometric study of antioxidant activity of pomiferin, isopomiferin, osajin and catalposide.
abstract: The antioxidant properties of pomiferin, isopomiferin, osajin and catalposide are evaluated. The electrochemical behaviour of these compounds at a carbon paste electrode was studied using square wave voltammetry. Oxidative signals, optimized frequencies and appropriate pH acetate buffer conditions were determined. The detection limits (3S/N) for pomiferin, isopomiferin, osajin and catalposide were estimated to be 50 pg/ml, 800 pg/ml, 40 pg/ml and 10 ng/ml, respectively. Furthermore, spectrometric test was employed with 2,2-diphenyl-1-picrylhydrazyle (DPPH) to evaluate the antioxidant activities of these compounds. Based on the obtained results, the highest antioxidant activity measured by DPPH tests was found at pomiferin followed by isopomiferin. The activities of osajin and catalposide were undetectable. The protective effects of pomiferin, isopomiferin, osajin and catalposide on DNA exposed to oxygen radicals in vitro were also studied. Changes in height of oxidative signals for the four bases (guanine, thymine, adenine and cytosine) were measured for DNA exposed to oxygen radicals, generated by Fenton's reaction, non-oxidized ssDNA (50 microg/ml) displayed well developed signals; however, after oxidative damage the observed oxidative signals decreased. Significant protective effects were observed for pomiferin and osajin. Decreased effect was observed for isopomiferin while a further reduced protective effect was seen for DNA exposed to catalposide. Based on the obtained results, pomiferin had the highest antioxidant activity followed by isopomiferin, osajin and catalposide.
authors.affiliation: Department of Plant Biology, Faculty of Agronomy, Mendel University of Agriculture and Forestry Zemedelska 1, CZ-613 00 Brno, Czech Republic.
authors.forename: Vaclav
authors.initials: V
authors.lastname: Diopan
authors.forename: Petr
authors.initials: P
authors.lastname: Babula
authors.forename: Violetta
authors.initials: V
authors.lastname: Shestivska
authors.forename: Vojtech
authors.initials: V
authors.lastname: Adam
authors.forename: Milan
authors.initials: M
authors.lastname: Zemlicka
authors.forename: Margita
authors.initials: M
authors.lastname: Dvorska
authors.forename: Jaromir
authors.initials: J
authors.lastname: Hubalek
authors.forename: Libuse
authors.initials: L
authors.lastname: Trnkova
authors.forename: Ladislav
authors.initials: L
authors.lastname: Havel
authors.forename: Rene
authors.initials: R
authors.lastname: Kizek
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology; D001578:Benzopyrans; D004563:Electrochemistry; D005960:Glucosides; D006863:Hydrogen-Ion Concentration; D007529:Isoflavones / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology; D015394:Molecular Structure; D010084:Oxidation-Reduction / Q000187:drug effects; D013053:Spectrophotometry / Q000379:methods*
chemical_list: D000975:Antioxidants; D001578:Benzopyrans; D005960:Glucosides; D007529:Isoflavones; C533098:isopomiferin; C474837:pomiferin; C006928:catalposide; C485800:osajin