title: Polyphenol contents and antioxidant activity of Maydis stigma extracts.
abstract: The antioxidant activity and contents of various polyphenol classes in the silks of fifteen maize hybrids with economic importance in Serbia were evaluated. Total polyphenols, tannins and proanthocyanidins were determined spectrophotometrically, after extraction of plant material with 70% aqueous acetone under sonication at room temperature. In addition, flavonoid content was determined. Antioxidant activity of aqueous acetone extracts was evaluated by FRAP assay. A positive linear correlation between antioxidant activity and contents of all investigated polyphenol classes was established. The highest antioxidant activity was observed in the extract of NS 640 hybrid, which had high levels of all polyphenol classes examined. Results suggested strongly that polyphenol content should be considered as an important feature of the herbal drug Maydis stigma. For that reason, the biological source of this herbal drug needs to be more precisely defined, as observed activities and polyphenol contents were greatly dependent on plant material source.
authors.affiliation: Institute of Pharmacognosy, School of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia and Montenegro. zmaksim1@pharmacy.bg.ac.yu
authors.forename: Zoran
authors.initials: Z
authors.lastname: Maksimović
authors.forename: Dorde
authors.initials: D
authors.lastname: Malencić
authors.forename: Nada
authors.initials: N
authors.lastname: Kovacević
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D005419:Flavonoids / Q000302:isolation & purification* / Q000494:pharmacology*; D029001:Herbal Medicine; D007501:Iron / Q000737:chemistry; D010084:Oxidation-Reduction; D010636:Phenols / Q000302:isolation & purification* / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D059808:Polyphenols; D013053:Spectrophotometry; D003313:Zea mays / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D007501:Iron