title: Phenolic acids, hydrolyzable tannins, and antioxidant activity of geopropolis from the stingless bee Melipona fasciculata Smith.
abstract: Geopropolis is a mixture of plant resins, waxes, and soil produced by the stingless bee Melipona fasciculata Smith. This paper describes the antioxidant activity and chemical composition of geopropolis produced by M. fasciculata. The total phenolic content determined with the Folin-Ciocalteu reagent was highest in the ethyl acetate fraction and hydroalcoholic extract. Antioxidant activity was assayed by the in vitro DPPH, ABTS, and FRAP assays. The hydroalcoholic extract and fractions of geopropolis, except for the hexane fraction, exhibited antioxidant activity against DPPH, ABTS, and FRAP. The phenolic compounds were identified by HPLC-DAD-MS on the basis of the evaluation of their UV-vis absorption maxima (λmax) and mass spectral analysis. Eleven compounds belonging to the classes of phenolic acids and hydrolyzable tannins (gallotannins and ellagitannins) were tentatively identified. These compounds are responsible for the antioxidant activity and high phenolic content of geopropolis produced by M. fasciculata.
authors.affiliation: Laboratório de Imunofisiologia and ‡Laboratório de Farmacognosia, Universidade Federal do Maranhão , Av. dos Portugueses 1966, 65085-580 São Luı́s, Maranhão, Brazil.
authors.forename: Richard Pereira
authors.initials: RP
authors.lastname: Dutra
authors.forename: Bruno Vinicius de Barros
authors.initials: BV
authors.lastname: Abreu
authors.forename: Mayara Soares
authors.initials: MS
authors.lastname: Cunha
authors.forename: Marisa Cristina Aranha
authors.initials: MC
authors.lastname: Batista
authors.forename: Luce Maria Brandão
authors.initials: LM
authors.lastname: Torres
authors.forename: Flavia Raquel Fernandes
authors.initials: FR
authors.lastname: Nascimento
authors.forename: Maria Nilce Sousa
authors.initials: MN
authors.lastname: Ribeiro
authors.forename: Rosane Nassar Meireles
authors.initials: RN
authors.lastname: Guerra
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000032:analysis* / Q000378:metabolism; D001516:Bees / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D047348:Hydrolyzable Tannins / Q000032:analysis* / Q000378:metabolism; D062385:Hydroxybenzoates / Q000032:analysis* / Q000378:metabolism; D013058:Mass Spectrometry; D011429:Propolis / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D047348:Hydrolyzable Tannins; D062385:Hydroxybenzoates; D011429:Propolis; C017616:phenolic acid