CHEMICAL PROFILE AND ANTIOXIDANT ACTIVITY OF GEOPROPOLIS FROM Melipona subnitida COLLECTED INSIDE AND OUTSIDE THE NEST

Melipona subnitida (jandaira) is a species of stingless bee endemic to the Caatinga, a dry forest in the northeastern Brazilian semiarid. Propolis is a product containing beeswax and plant resin. It contains compounds that can be able to prevent health problems by protecting cells against damage by oxidative agents. M. subnitida produces geopropolis, a mixture of propolis with soil. Samples of geopropolis of M. subnitida, one of inside and another outside of the nest from a hive in the municipality of Mossoro (northeastern Brazil) were analyzed by HPLC-PDA-ESI-MS/MS and their antioxidant activity evaluated by the DPPH and beta-carotene/linoleic acid methods. Both samples exhibited similar chemical profile, characterized by 26 phenolic compounds, however, the compounds detected were more abundant in sample collected from inside of the nest. They were tentatively characterized as galloyl hexoses, coumaroyl-O-galloyl-hexoses, cinnamoyl-O-galloyl-hexoses, coumaroyl- and cinnamoyl- galloyl hexoses, phenylpropanoyl-O-benzoyl hexoses, flavanones and ellagitannins. Flavonoids, galloyl hexoses, coumaroyl-O-galloyl-hexosides, cinnamoyl-O-galloyl-hexosides and coumaroyl-cinnamoyl-galloyl hexosides were reported previously in this genus, however ellagitannins and phenylpropanoyl-O-benzoyl hexoses are reported for the first time. Comparing the antioxidant activity of the geopropolis samples from inside and outside of the nest, the latter was higher than the former.

Automated summary

This study analyzed the chemical composition and antioxidant activity of M. subnitida geopropolis samples from inside and outside the nest in northeastern Brazil. The results showed that both samples contained 26 phenolic compounds, with the compounds being more abundant in the sample collected from inside the nest. Additionally, ellagitannins and phenylpropanoyl-O-benzoyl hexoses were reported for the first time. The antioxidant activity of the geopropolis sample collected from outside the nest was higher than that from inside.