Caracterização química e fitogeográfica de geoprópolis das espécies de abelhas nativas do Maranhão

Abstract

We analyzed the pollen spectrum of one hundred and thirty geopropollis samples of the following species of Melipona: M. fasciculata, M. flavolineata, M. seminigra and M. subnitida. Samples were collected in the municipality of Santa Luzia do Paruá, in the Alto Turi region, which belongs to the Amazon region, in the state of Maranhao. The objective of this study was to recognize the phytogeographic and chemical profile of the Melipona geopropolis samples and to help characterize the resin supplying vegetation for these bees. The geopropolis samples were collected monthly from December/2013 to December/2014 from nests kept in wooden boxes in a particular meliponary. The palynological analysis was done according to the standard methodology proposed by Barth (1998). The chemical profile of the samples was determined by high performance liquid chromatography (CLAE), liquid chromatography coupled to mass spectrometry (LC-MS) and gas chromatography coupled to mass spectrometry (GC / MS) analysis. And also included quantification of the content of total polyphenols (TPT) through the use of Folin-Ciocalteau reagents and sodium carbonate 20%; total flavonoids (TFT) by the photocolorimetric method with methanolic solution of aluminum chloride (AlCl3) 5%, and the antioxidant activity of the hydroalcoholic extracts of geopropolis by the DPPH free radical assay (Brand-Williams et al). A total of 148 pollen types were identified, distributed in 49 families, 108 genera and two unidentified types. In the geopropolis samples of M. subnitida 107 pollen types were distributed in 40 families and 72 genera. In the M. seminigra, 93 pollen types, 37 families and 70 genera were observed. For M. flavolineata were 98 pollen types, belonging to 33 families and 72 genera. In M. fasciculata there were 64 pollen types, 28 families and 53 genera, being therefore the one with the lowest pollen richness in the samples. Fabaceae presented the highest richness of pollen types (39 types), followed by Rubiaceae (11 types). The pollen types most common to Melipona species were: Attalea speciosa, Anacardium, Borreria verticilatta, Baccharis, Clusia, Chamaecrista, Croton, Euterpe/Syagrus, Eucalyptus, Hyptis, Mauritia, Mimosa pudica, M. caesalpinaefolia, Mouriri, Myrcia /Psidium, Protium And Symphonia globulifera, which characterized the phytogeographic profile of the geopropolis of this region. Aniardium, Ardisia, Baccharis, Caryocar, Clusia, Clusia grandiflora, Eucalyptus, Eupatorium, Hyptis, Myrcia/Psidium, Platonia insignis, Protium, Spondias, Symphonia globulifera, Tapirira and Vismia were the possible resin species suppliers for the Melipona geoprópolis . The presence of various compounds which have been tentatively characterized as quinic acid, benzophenone derivatives, O-glycosylated flavonoid and xanthones have been disclosed. The mangiferin compound was present in all samples. It was also verified the presence of benzophenones that appear to be involved in the biosynthesis of glycosylated xanthones. The extracts presented flavonoid contents above 2%, which allows them to be classified according to Brazilian legislation as a geopropolis with a high content of flavonoids. For the antioxidant activity a variation of 2.20 to 44.35% occurred. There was a variation in the content of phenolic compounds and flavonoids among the different samples of the four Melipona species analyzed. The results indicate that the bee species and the collection season, as well as the interaction between these factors, influence the concentration of bioactive compounds in the geopropolis. Thus, we believe that the results obtained contribute significantly to the geopropolis characterization of stingless bees from Amazonia Maranhense and show the importance of expanding the studies of chemical characterization and standardization of product quality parameters, since thisis a rich source of bioactive compounds with great pharmacological potential.