Chemical composition, antioxidant and antibacterial properties of Juniperus excelsa M. Bieb. leaves from Türkiye

Juniper species are especially used in traditional medicine due to their analgesic, diuretic, antibacterial, antimicrobial, anti-inflammatory, and liver-protective effects. The goal of the present study was to investigate the chemical compounds, antioxidant, and antimicrobial properties of essential oil of Juniperus excelsa M. Bieb., a species of juniper with a large spread area in Turkey. Essential oils were extracted by the hydro-distillation method. The components of the hydro distilled oil samples were analyzed by gas chromatography-mass spectrometry (GC-MS). In the study, the essential oil was evaluated for its antibacterial activity against six bacterial strains consisting of two Gram (+) and four Gram (–) by the agar disc diffusion method. Additionally, the antioxidant properties of the oil were determined by TEAC/ABTS+ free radical scavenging assay. As a result, there were 27 compounds in the essential oil of J. excelsa. Of the 27 essential oil components identified, α-pinene (40.59%), α-cedrol (18.15%), β-myrcene (4.53%), and limonene (3.84%) were determined as the main components in total 91.54% of the essential oil. As a result, it was observed that the examined juniper essential oil showed a weak but effective antibacterial activity against all bacterial strains compared to the control agents, and also, the examined oil had low but valuable antioxidant activity.