Estudo químico e avaliação da atividade antioxidante da geopropolis da abelha sem ferrão jandaira (Melipona subnitida Ducke)

Abstract

Mepolina bees use different materials to build and protect their nests against their enemies, such as resins, wax and clay. The mixture of this material of hard consistency and coloring characteristic of the clay of the region is called geopropolis. Some Melipona species are widely distributed in various regions, such as species jandaira which is typical of the interior and is endemic in northeastern caatinga.This paper describes the chemical and evaluation of antioxidant activity of a sample of geopropolis jandaira bee (Melipona subnitida Ducke). The chemical study resulted in the isolation and identification of seven flavonoids 7-methoxynarigenina, 7-methoxy aromadendrina, 5-methoxyaromadendrina, 7,4'-dimethoxy-aromadendrina, 3-methoxy-quercetin, 4'-methoxykanferol , 5-methoxy-kanferol and two glycosylated Phenylpropanoids 6-O-p-coumaroil-D-galactopyranose and 1-O-coumaroil 6-O-cinnamoyl-β-D-glucopyranoside. The structures of the isolated compounds were elucidated by analysis of NMR spectra of ¹H and ¹³C, including bidimensional correlation techniques and LC-ESI-MS. The complete elucidation of the substance 3 (6-Op-coumaroil-D-galactopyranose) confirms that these are two unprecedented anomers. To determine the total phenolic content, Folin-Ciocalteu was used and to evaluate the antioxidant potential, tests were performed with DPPH, ABTS and β-caroteno/ácido linoleic system with the extract and fractions EtOH hexane, EtOAc and MeOH/H2O. The EtOH extracts and fractions tested were correlated with thetotal phenolic content and antioxidant activity. The AcOEt fraction showed the highest activity during all the tests which was the aim of this study.. The EtOAc fraction showed the highest activity during all the tests which was the aim of this study. All the isolated substances from geopropolis jandira are being described for the first time, with emphasis on the substance 6-O-p- coumaroil -D-galactopyranose that is unprecedented.