Bee Species, Botanical Sources and the Chemical Composition of Propolis from Yucatan, Mexico

Propolis is used by corbiculated bees to protect the bee hive; it is mostly used to seal cracks, to reduce or prevent microbial growth and to embalm invaders. Different factors have been reported to influence the chemical composition of propolis, including bee species and the flora surrounding the hive. Nevertheless, the majority of the studies are focused on propolis produced by Apis mellifera, while studies on the chemical composition of propolis produced by stingless bees are still limited. In this investigation, the chemical composition of 27 propolis samples collected in the Yucatan Peninsula from A. mellifera beehives, together with 18 propolis samples from six different species of stingless bees, were analyzed by GC-MS. Results showed that lupeol acetate and β-amyrin were the characteristic triterpenes in propolis samples from A. mellifera, while grandiflorenic acid and its methyl ester were the main metabolites present in samples from stingless bees. Multivariate analyses were used to explore the relationship between bee species and botanical sources on the chemical composition of the propolis samples. Differences in body size and, therefore, foraging abilities, as well as preferences for specific botanical sources among bee species, could explain the observed variation in propolis chemical composition. This is the first report on the composition of propolis samples from the stingless bees Trigona nigra, Scaptotrigona pectoralis, Nannotrigona perilampoides, Plebeia frontalis and Partamona bilineata.