Chemical profile, allelopathic, antibacterial and antioxidant potential of the essential oil from Aleppo pine (Pinus halepensisMiller) needles

This study highlighted the chemical composition of Tunisian Aleppo pine (Pinus halepensis) essential oil and its biological activities as allelopathic, antioxidant and antibacterial capacities depending on the collection region. The highest essential oil yield was obtained in Boukornine (0.67%) followed by Bizerte (0.50%) and Djerissa (0.25%). The analysis of the chemical composition of Aleppo pine essential oils showed considerable qualitative variability of major components, namely β-caryophyllene (12.27-14.26%), myrcene (11.51-14.26%), p-cymene (8.07-10.57%) and α-pinene (6.57-9.37%). The essential oil of Djerissa had stronger allelopathic effect against Triticum aestivum than Bizerte and Boukornine owing to its richness in monoterpenes, especially myrcene. However, the essential oils of Bizerte and Boukornine had higher antioxidant and antibacterial capacities than Djerissa which could be related to the synergistic property associated with the high level of the sesquiterpene β-caryophyllene with the other essential oil constituents. These results suggested that Aleppo pine essential oil could give a hope toward production of eco-friendly bio-herbicides at least against Triticum aestivum and also as a source of natural antioxidant and antibacterial agents that could be used as food additives.