Estudo químico de própolis do estado de Minas Gerais

Abstract

Propolis is a complex product elaborated by bees from tree resins, waxes, pollen, plant fragments and bee salivary secretions. It is used to seal and protect the hive against insects and microorganism attacks, and to improve the temperature and moisture controls. Propolis has good biologic properties like antibiotic, microbicide , anti-cariogenic, antifungic, antioxidant, antitumoural and cicatrization activities. Propolis composition varies accordingly to the local flora and can have brown, red, black, white or green color. The green propolis distinguish itself from the others, because in its constitution, there is a resin extracted from “ alecrim-do-campo” buds (Baccharis dracunculifolia), an endemic bush in certain regions from Brazil. At this work, green propolis samples were analyzed by chromatographic (GC-MS, HT-HRGC-MS, HPLC and HPLC-APCIMS/MS), spectrophotometric (total phenols, flavonoids levels in quercetin equivalents and antioxidant activity) and gravimetric assays. Other propolis and plants samples were analyzed for identification and verification of similarities in their constituents. The HPLC/MS and GC/EM techniques furnished the best information about the chemical composition of the propolis samples. Cinnamic acid and derivatives, flavonoids, high chain alkanes and alcohols, carboxylic acids and derivatives (main ly esthers), nonhydroxilated aromatic compounds and terpenoids were identified. Many compounds could not be identified specially the four isomers with MW 270 and one compound with MW 256. All the propolis samples collected in areas where Baccharis dracunculifolia was native, showed a chemical marker, a non -identified compound with MW of 256 Da. This compound was found in this plant, but not in other plants samples neither in propolis samples collected where this plant was not present. The biological tests with PSB and PSG samples showed reasonable bactericide activity, although the minimum inhibitory concentration could not be determined.