Potential impacts ofPinus halepensisMiller trees as a source of phytochemical compounds: antibacterial activity of the cones essential oil andn-butanol extract

The Aleppo pine (Pinus halepensisMiller) trees grown in the agricultural lands with high biodiversity, and considered as a potential source for chemical and therapeutic compounds. Essential oil (EO) andn-butanol fraction (But-fr) of Aleppo pine cones were evaluated against the growth of four plant bacterial pathogens (Dickeya solani,Pectobacterium atrosepticum,Ralstonia solanacearum, andAgrobacterium tumefaciens) and four human pathogenic bacteria (Bacillus subtilisATCC 6633,Sarcina luteaATCC 9341,Escherichia coliATCC 8739, andStaphylococcus aureusATCC 6538). The diameter of the inhibition zone (IZ) and the minimum inhibitory concentrations (MICs) were measured. At 2000 mu g/mL, But-fr showed the strongest activity againstD. solani,P. atrosepticum, andR. solanacearumwith inhibition zones (IZs) of 14.33 mm, 12.33 mm, and 15.33 mm, respectively. At 2000 mu g/mL, EO showed the best activity againstA. tumefacienswith an IZ value of 12.67 mm. Weak activity was observed by applying the EO and But-fr againstB. subtilisandS. lutea, while good activity was recorded by But-fr againstE. coliandS. aureuswith IZs values of 13.67 mm and 11.33 mm, respectively, at 2000 mu g/mL. Gas chromatography-mass spectrometry (GC/MS) analysis reported that the EO from cones contained mainly caryophyllene (15.17%),alpha-pinene (13.51%), and caryophyllene oxide (12.57%); But-fr contained 3,4-dimethyldihydrofuran-2,5-dione (36.25%), and 2-methylenecholestan-3-ol (18.12%). The phytochemical But-fr extract of Aleppo pine cones demonstrated moderate antibacterial effects against the studied bacteria.