Investigation on chemical composition, antioxidant and antimicrobial potential of Pulicaria mauritanica essential oil applied by direct addition or vapor contact

Analysis of essential oil (EO) obtained from Pulicaria mauritanica in southeast of Morocco allowed the identification of 23 components, which accounted for 91.6% of the total oil in which carvotanacetone was the predominant constituent (55.1%), followed by (E)-Phytol (6.8%), β-caryophyllene (6.6%) and Thujopsene (4.9%). Antimicrobial potential of P. mauritanica oil in liquid and vapor phase against different fungal strains (Penicillium expansum, Alternaria sp., Rhizopus stolonifer, Fusarium oxysporum f. sp. albedinis and Aspergillus brasiliensis ATCC 16404) and bacterial strains (Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 8739, Salmonella abony NCTC 6017) was determined by agar dilution method and disc volatilization method. S. abony was the most sensitive bacteria, providing the lowest growth with an MIC equal to 0.039 mg mL-1. Alternaria sp., R. stolonifer and A. brasiliensis were found to be fungal susceptible to the EO of P. mauritanica and were completely inhibited in the presence of the liquid oil at 0.25 µL mL-1. However, the mycelium growth was totally inhibited in the presence of the vapor generated by 0.125 µL mL-1 air for Alternaria sp., F. oxysporum albedinis, A. brasiliensis and R. stolonifer. Furthermore, the P. mauritanica EO showed an important antioxidant property determined by 1, 1-diphenyl-1-picrylhydrazyl (DPPH) assay and by β-carotene bleaching test.