The chemical profiles of propolis ethanol extracts were studied by GC-MS (after silylation). All three samples of T. laeviceps propolis displayed identical profiles, while T. melanoleuca propolis was different from them (Total Ion Chromatograms: S15 Fig). Moreover, the GC-MS profiles for propolis of both species did not coincide with any known propolis type and demonstrated the lack of plant secondary metabolites previously found in propolis. For this reason, it was necessary to isolate and identify individual compounds in order to reveal the specific chemistry and, if possible, the plant origin of the studied stingless bee propolis.