Fractionation of Schinus molle essential oil: chemical composition, antimicrobial, insecticidal and anti-inflammatory potentials

The study aimed to investigate the impact of fractionation on Schinus molle essential oil composition and antimicrobial properties. The crude oil was fractionated using open-column chromatography, and gas chromatography–mass spectrometry (GC–MS) identified Dl-limonene as chemotype (31.14%). Unfractionated oil showed substantial antimicrobial effectiveness against various microorganisms, including Enterococcus faecalis ATCC 29212, with inhibition zones (IZ) ranging between 12 and 29 mm. After fractionation, the hydrocarbon fraction exhibited enhanced antimicrobial properties, with inhibition zones of 40 mm and 45 mm and a minimum inhibitory concentration (MIC) of 0.031 mg/mL against methicillin-resistant Staphylococcus aureus and Enterococcus faecalis ATCC 29212. Additionally, the oil demonstrated robust insecticidal activity against Tribolium castaneum (RD₅₀ = 0.010 µL/cm²; LD₅₀ = 0.019 µL/cm²) and Rhyzoperta dominica (RD₅₀ = 0.015 µL/cm²; LD₅₀ = 0.010 µL/cm²), and potent anti-inflammatory activity by suppressing nitric oxide production (51.41% at 62.5 μg/mL) without cytotoxicity toward RAW 264.7 macrophage cells. These results underscore the applicability of Schinus molle essential oil as efficient antimicrobial, insecticidal, and anti-inflammatory agents in agricultural, food, and pharmaceutical sectors.