Chemical composition of essential oil of Jatropha curcas L. leaves and its antioxidant and antimicrobial activities

Jatropha curcas L. is a perennial energy crop in the Euphorbiaceae family that received much attention for its bio-oil multiple uses. This study was designed to determine the composition and antioxidant, antimicrobial activities of jatropha's essential oil grown under Moroccan ecological conditions. The gas chromatography coupled with mass spectrometry (GC/MS) analysis revealed that the oil contains 39 compounds, with dominant the δ-cadinene (9.6%), α-epi-cadinol (7.38%), pulegone (5.95%), chrysanthenyl acetate (5.26%), α-cadinol (4.32%), thymol (4.03%). The antioxidant activity was evaluated by radical 2.2-diphenyl-1-picrylhydrazyl (DPPH) and by reducing power test. The result showed a moderate activity with the concentration providing 50% inhibition (IC50) 314 μg/mL and 298 μg/mL, respectively. The essential oil was used for antimicrobial activity against six bacteria and three yeasts. The yeasts strains were the most sensitive among the microorganisms tests, with minimum inhibitory concentration (MIC) ranging between 0.3 mg/mL and 0.6 mg/mL, followed by Gram-positive strains (0.3 mg/mL-1.2 mg/mL) and Gram-negative (0.6 mg/mL-2.4 mg/mL) apart from Pseudomonas aeruginosa which was a resistant strain to J. curcas L. essential oil. The results of this study showed that essential oil of J. curcas L. contains compounds with an antioxidant and antimicrobial power against several pathogenic strains and these properties may be employed in the management of microbial infections.