Phytochemical Profile, Antioxidant and Antibacterial Activity of the Essential Oil of Luma Chequen (Molina) A. Gray from Peru

Background: Luma chequen belongs to Myrtaceae family and it is known as “arrayan”. In the traditional medicine from Peru, L chequen is used as aromatic plant, anti-inflammatory and hypocholesterolemic. Objective: To determine the phytochemical profile, evaluate the antioxidant and the antibacterial activity of L. chequen essential oil. Material and Methods: In the analysis of the volatile components a Gas Chromatography coupled to Mass Spectrometry (GC-MS) was used to identify the content of terpenes and sesquiterpenes. 2,2-diphenyl-1-picrylhydrazyl (DPPH) was the method used to determine the antioxidant activity and obtain the half inhibitory concentration (IC₅₀). For the antibacterial activity, a colorimetric macrodilution method was carried out to evaluate the effect of the essential oil of L. chequen against Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922. Results: The analysis by GC-MS showed two major components alpha-pinene (62.89%) followed by 1,8-cineole (11.94%), and propanoic acid, 2-methyl-, 2-methylpropyl ester with 8.67%. In the antioxidant activity against DPPH radical, the essential oil of L. chequen showed an IC₅₀ equivalent to124.60 ± 2.0 μg/mL. In the antibacterial activity, L. chequen had an MIC (minimum inhibitory concentration) for Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922 of 4.35 ± 0 μg/mL and 8.71 ± 0 μg/mL respectively. Conclusion: L. chequen presented monoterpene compounds as main phytoconstituents as well as antioxidant and antibacterial activity in vitro. The essential oil might be used as antimicrobial agent in the future overall against S. aureus.