Leaves from Piper aduncum and Grias neuberthii are used in Ecuadorian Amazon communities as traditional medicine for their antiseptic and antihemorrhagic properties. The present study was designed to elucidate the chemical composition and biological properties of methanolic extracts from these plants, evaluating the effect of the plant material state (fresh vs. dry). Leaf samples collected in Tena, Ecuador, were macerated in methanol, lyophilized, and the resulting extracts were employed for chemical characterization and biological activity assessment.
Phytochemical screening and metabolomic analysis identified a wide spectrum of secondary metabolites. The results indicated significant differences between species: G. neuberthii showed higher concentrations of total phenols and flavonoids, such as quinic acid and catechin, whereas P. aduncum had a greater alkaloid content and glycosylated flavonoids. Furthermore, dry leaf extracts exhibited a more robust phytochemical profile.
For biological activity, the extracts demonstrated antimicrobial efficacy against model microorganisms and multidrug-resistant strains, including Staphylococcus aureus and Pseudomonas aeruginosa, with dry leaf extracts showing stronger inhibition. Additionally, hemolytic activity assessment revealed that P. aduncum had low hemolysis even at high concentrations, supporting its safe topical use, while G. neuberthii exhibited dose-dependent hemolysis. The results validate the traditional uses of P. aduncum for infections and G. neuberthii as a topical analgesic and suggest their complementary, synergistic potential. This study confirms the presence of compounds of therapeutic interest and highlights the ethnopharmacological value of these plants for developing natural antimicrobial agents.

Keywords: antimicrobial activity, Grias neuberthii, hemolysis, Piper aduncum, secondary metabolites.