Chemical composition and biological activity of propolis from Brazilian Meliponinae

Twenty-one propolis samples produced by 12 different Meliponinae species we re analyzed by GC-MS. Several chemical types of stingless bees' propolis co uld be grouped, according to the prevailing type of compounds like: "gallic acid", "diterpenic" and "triterpenic" types. The results confirm that neit her the bee species nor the geographical location determine the chemical co mposition of Meliponinae propolis and the choice of its plant source, respe ctively. This could be explained by the fact that Meliponinae forage over s hort distances (maximum 500 m) and thus use as propolis source the first pl ant exudate they encounter during their flights. The antibacterial, antifun gal and cytotoxic activities of the samples were also investigated. Most sa mples had weak or no activity against E. coli, weak action against Candida albicans. Some of them showed significant activity against St. aureus., pre sumably connected to the high concentration of diterpenic acids. Samples ri ch in diterpenic acids possessed also high cytotoxic activity (Artemia sali na test).