Chemical Variability and Antioxidant Activity of Stingless Bee Melipona seminigra Geopropolis from Different Amazon Regions

Melipona seminigra geopropolis is a significant income source for many people in Amazonia due to its medicinal and nutritional properties. This study describes the chemical composition of geopropolis from local producers across five different locations in Manaus and Iranduba in the State of Amazonas, Brazil. Using chemical analysis techniques such as nuclear magnetic resonance, mass spectrometry (ion-trap analyzer), and liquid chromatography coupled to high resolution mass spectrometry (time-of-flight analyzer), the presence of organic acids, flavonoids, and benzophenones was annotated. Chemometric analysis, including principal component analysis (PCA) and hierarchical cluster analysis (HCA) of the mass spectrometry data, revealed a relationship between the chemical composition of the samples and the geographical sources. The antioxidant activity measured using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical assay showed values ranging from 57.01 to 142.10 µg mL-1, while total phenolic content ranged from 248.85 to 367.01 µg mL-1. These findings provided new insights into a product that has not been extensively studied.