Background: Infusions of Maiten (Maytenus boaria) leaves are used in folk medicine as an antipyretic and for skin allergic rash treatment. Antioxidant, antipyretic and anti-inflammatory properties of medicinal plants have been attributed to phenolic compounds presence. This work, the first in this type, reports the presence of total phenolic compounds (TPC), total flavonoids (TFC), and the antioxidant activity by DPPH, FRAP and ORAC methods of extracts of maiten leaves, including an infusion; also, antimicrobial activity on Gram + and Gram − bacteria were determined. In addition, the presence of Quercetin and catalase were determined, and the FTIR spectrum was done.

Results: The best values of TPC and TFC were 20.55 g_GAE/kg_leaves, and 23.69 g_QE/kg_leaves, respectively, in an ethanolic extract. Best antioxidant activities were obtained in a methanolic extract for DPPH, aqueous extract for FRAP. No significant differences were observed in ORAC activity determination of aqueous, ethanolic, and methanolic extracts and a maiten infusion, with an average value of 22.41 mmol_TE/kg_leaves. In the case of antimicrobial activity, extract of maiten leaves can inhibit the growth of bacteria as Escherichia coli and Listeria monocytogenes, among others.

Conclusions: M. boaria leaves are an important source of phenolics compounds with antioxidant activity; these properties are observed in extracts and infusions. In addition, the extract of maiten leaves produces the inhibition of pathogens Gram+ and Gram− bacteria, showing the great therapeutic potential of this plant used in folk medicine.