No abstract

Propolis, Polyphenols, Volatiles, GC/MS, Antibacterial Activity Four samples of Brazilian propolis were investigated by GC/MS of different fractions. 32 volatile compounds, (10 of them new for propolis), as well as 12 more polar compounds (one of them new for propolis) were identified. Antibacterial activity was found in some propolis fractions.

Four labdane-type diterpenic acids and syringaldehyde were isolated and identified from Brazilian propolis. A ll the com pounds exhibit antibacterial activity. The diterpenes, found for the first time in propolis, are typical for som e Araucaria species and thus indicate a possible plant source of Brazilian propolis.

Propolis, A raucaria angustifolia, B accharis dracunculifolia, Eucalyptus citriodora, Botanical Origin Propolis and plant secretions from three species, most frequently mentioned as botanical sources of the bee glue in Brazil (B accharis dracunculifolia, A raucaria angustifolia and E u ca lyptus citriodora) have been investigated using GC-MS. Based on chemical evidence, B. dra cunculifolia was shown to be the main propolis source in Säo Paulo state. The antibacterial and antifungal activities of all four materials were also tested, the most active being propolis and B accharis leaf exudate.

Twenty-one propolis samples produced by 12 different Meliponinae species were analyzed by GC-MS. Several chemical types of stingless bees’ propolis could be grouped, according to the prevailing type of compounds like: “gallic acid”, “diterpenic” and “triterpenic” types. The results confirm that neither the bee species nor the geographical location determine the chemical composition of Meliponinae propolis and the choice of its plant source, respectively. This could be explained by the fact that Meliponinae forage over short distances (maximum 500 m) and thus use as propolis source the first plant exudate they encounter during their flights. The antibacterial, antifungal and cytotoxic activities of the samples were also investigated. Most samples had weak or no activity against E. coli, weak action against Candida albicans. Some of them showed significant activity against St. aureus., presumably connected to the high concentration of diterpenic acids. Samples rich in diterpenic acids possessed also high cytotoxic activity (Artemia salina test).