Analysis of the chemical constituents of Myrcia glomerata G.Burton & E.Lucas leaves and assessment of their antimicrobial, antioxidant, and antibiofilm potential against pathogenic microorganisms

The Myrtaceae family plays a significant role in the Angiosperm landscape in Brazil, standing out as one of the most relevant. Within this context, the genus Myrcia ranks as the fourth largest, and its plant extracts and essential oils from these species are recognized as a valuable source of plant bioactives. In this context, Myrcia glomerata, popularly known as guamirim, stands out. Despite belonging to the Myrtaceae family, there is a lack of detailed research on its biological activities and chemical composition. The phytochemical investigation of the different plant extracts: ethanolic (EE), methanolic (ME), hexane (HE), acetone (AE), ethyl acetate (EAE) and dichloromethane (DE) revealed the presence of saponins, free steroids, alkaloids, anthocyanins, anthocyanidins, flavones, flavonols, xanthones, chalcones, aurones, flavononols and tannins, leading to the quantification of phenolic compounds (flavonoids, tannins, and alkaloids). The essential oil of the leaves, identified by gas chromatography coupled to mass spectrometry (GC-MS) identified 29 compounds, corresponding to 97.54% of the total area of the essential oil of M. glomerata. The main compounds found were sesquiterpenes, Elemicin (76.85%), Elixene (3.99%), E-caryophyllene (2.25%). EE showed the best antimicrobial potential, with concentrations ranging from 0.39 to 25 mg.mL-1, with Staphylococcus aureus and Proteus mirabilis strains being more susceptible in EE, ME and AE, showing 98.72%, 96.23% and 88.60% antioxidant activity, respectively. As for the antibiofilm potential, ME showed the greatest biomass reduction (90.53%) for Salmonella enterica Typhimurium, with cell viability of 9.02%. These results demonstrate the potential of EE and ME extracts from M. glomerata, representing a possible source of natural bioactives to be used in pharmaceuticals for the control of resistant microorganisms.