Comparative analysis of essential oils from two Satureja species; extraction methods, chemical composition, and antimicrobial activities

Abstract

This study aimed to investigate the antibacterial and antifungal properties of the essential oils extracted from two medicinal plants, Satureja sahendica and Satureja spicigera. Three different methods, including Multi-walled carbon nanotubes (MWCNT) extraction, Clevenger hydrodistillation (Clevenger HD) extraction, and simultaneous distillation-extraction (SDE), were employed to isolate the volatile components of the two species, and then extraction efficiencies were compared. The composition of the essential oils was analyzed using gas chromatography-mass spectrometry (GC-MS). The results revealed that the two plant species contain a significant amount of oxygenated monoterpenes, while sesquiterpenes have a lower percentage. The main compounds of S. sahendica and S. spicigera essential were thymol (10.28–46.83%), carvacrol (7.81–36.88%), terpinolene (5.73–28.53%), ɣ-terpinene (14.76–16.27%), linalool (5.11–14.43%), p-cymene (8.23–12.33%), terpinen-4-0l (4.93–9.97%), germacerene (8.19–9.44%), α-pinene (5.22–8.41%), thymoquinane (4.49–7.65%), 1,8-cineole (4.82–6.83%), spathulenol (3.01–5.47%). To study the antibacterial and antifungal effects of the obtained essential oils, the micro broth dilution method was used on four bacterial species, including Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Pseudomonas aeruginosa, as well as the fungus Candida albicans. The results indicated that both species essential oils had a high activity against C. albicans, while P. aeruginosa was the most resistant bacteria. Furthermore, it was found that S. sahendica essential oil exhibited a greater antimicrobial effect than S. spicigera. This study provides valuable insights into the antibacterial and antifungal effects of essential oils extracted from S. Sahendica and S. Spicigera, which have potential applications in medicinal industry.