The Vismia Vand. genus encompasses many species indigenous to the Amazon rain forest where they are popularly known as “Lacre” bark and leaves are widely employed by locals to treat dermatophytoses. The aim of this study was to investigate the chemical composition of essential oils (EOs) extracted from the aerial parts of the species Vismia guianensis (Aubl.) Choisy and Vismia cayennensis (Jacq.) Pers. and to assess their antimicrobial activity against the bacteria Staphylococcus aureus Rosenbach 1884 and Escherichia coli (Migula 1895) Castellani and Chalmers 1919 as well as the fungi Candida albicans (C.P. Robin) Berkhout 1923 and Candida parapsilosis (Ashford) Langeron & Talice 1932. The analysis of the chemical composition of the essential oil extracted from V. guianensis leaves (EOVg) indicated 46 components, of which three sesquiterpenes predominated, namely: (E)-caryophyllene (10.40%), α-copaene (29.45%), and (E)-nerolidol (24.06%). As to the essential oil from V. cayennensis leaves (EOVc), 61 components were identified, of which two oxygenated sesquiterpenes stood out as the main components, namely, germacrone (25.42%) and curzerene (25.29%). EOVg exhibited Minimum Inhibitory Concentration (MIC) of 1.56 µg/mL against the yeast C. parapsilosis whereas EOVc was active against the bacteria E. coli and S. aureus as well as the yeast C. parapsilosis. The results obtained in this study strongly recommend further research on the essential oils in question with a view to isolating and identifying the components responsible for their observed antimicrobial activities.

Background: Traditional medicine has inspired the scientific community to discover natural compounds with the ability to inhibit the enzyme acetylcholinesterase (AChE) and with significant antioxidant capacity. These themes are associated with therapeutic processes to decrease the symptoms of Alzheimer's disease (AD). Acetylcholine (Ach) is an important neurotransmitter in the central nervous system responsible for transmitting the nervous impulse and increasing intestinal motility and dilation of sphincters in the gastrointestinal tract. As the species Peumus boldus Molina is widely known and used in folk medicine to treat gastrointestinal discomfort, its constituents could have an affinity for AChE and could be used to treat AD. Materials and Methods: This study evaluated the chemical, inhibitory activity of AChE (using the Elmann method and in silico), antioxidant capacity (DPPH, ABTS, FRAP, and oxidation inhibition of the β-carotene/linoleic acid system), and quantification of total leaf phenols from a commercial sample of P. boldus. Results: The mass spectral analysis allowed identification of the alkaloids isoboldine, boldine, clocaurine, laurotetanine, N-methylurotetanine, reticuline, and N-methylcoclaurine. In the in silico prediction test, the alkaloid N-metillaurotetanine was the best acetylcholinesterase enzyme inhibitor, with energy of -10.1 kcal mol -1 . Conclusion: These results are of scientific relevance for the discovery of new drugs to treat dementia associated with Alzheimer's disease and stimulate the continuity of chemical and biological studies (anticholinesterase and antioxidant action) of prepurified fractions and substances isolated from P. boldus leaves.