Essential oils (EOs) from medicinal and aromatic plants are interesting products to be used as natural food preservatives. The EOs from the genus Satureja are reported to inhibit foodborne pathogens being worthy of use as food preservatives. Satureja macrantha is found in Western and Northwest Iran and commonly used as a food flavoring agent and for the treatment of urinary diseases. The objective of the present study was to identify the chemical composition of S. macrantha EOs at different growth stages (vegetative, flowering and fruiting stages) and to evaluate their biological activities. Chemical compositions were analyzed using GC-FID and GC-MS. The antibacterial activity was evaluated using the broth microdilution method against the foodborne pathogenic bacteria Staphylococcus aureus (ATCC23922), Enterococcus faecalis (ATCC29212) (Gram-positive), Enterobacter aerogenes (ATCC13046) and Escherichia coli. The antioxidant activity was estimated using the DPPH, ABTS and reducing power assays. The yields of S. macrantha EOs were in the range of 1.4–1.8%, thus scalable for the manufacture of food preservatives on an industrial level. The main compounds of EOs were carvacrol (42.7–48.2%), thymol (0.2–16.5%), p-cymene (10.1–14.7%) and γ-terpinene (7.9–9.1%) in all phenological stages examined. The strongest antibacterial activity (MICs = 5–20 µg/mL) of the EOs was recorded in samples obtained during the flowering stage where carvacrol (42.7%) and thymol (16.5) were present both at high percentages. On the other hand, the antioxidant activity was found to be slightly higher in the other stages. As the EO obtained at flowering showed the best inhibitory properties against foodborne pathogenic bacteria, it is suggested that plants at this stage can be selected as main sources of food preservative agents.

The natural compounds such as essential oils are getting more attention due to their potential usage in pharmaceuticals and possibly as natural herbicides. This study was conducted to identify the chemical compositions of essential oils from Foeniculum vulgare Mill. populations collected from different regions of Iran, Turkey, and Germany, and their antioxidant (DPPH·, ABTS·⁺ and reducing power methods) and phytotoxic activity (against Convolvulus arvensis L.). The results exhibited a significant variation in essential oils content (1.74-2.97%). The main compounds in essential oils were trans-anethole (15.23%−90.11%), estragole (4.00-63.72%), fenchone (0.03-12.62%) and limonene (1.05-13.04%). The results revealed that the essential oils have considerable antioxidant (IC₅₀ values in the range of 11.83-36.90 mg mL⁻¹ in DPPH, 7.65-20.13 mg mL⁻¹ in ABTS^·+ and EC₅₀ values in the range of 3.65-15.24 mg mL⁻¹ in reducing power assay) and phytotoxic activity. The results of this study can help in the development of natural antioxidants and herbicides.

Satureja macrantha C.A.Mey. is a medicinal plant which produces essential oils with antibacterial and antifungal activity. This study was carried out to determine the chemical composition of essential oils obtained from four Satureja macrantha populations growing in Iran, and to evaluate their antioxidant and antibacterial activities. The essential oils were obtained by hydrodistillation and analyzed by GC-FID and GC/MS. The main identified constituents were p-cymene, γ-terpinene, thymol and carvacrol. Although the population from Khodafarin was rich in thymol (36.5%), the population from Arasbaran showed a high content of p-cymene (34.7%). In comparison, the populations from Marand and Kaleybar possessed high quantities of carvacrol (42.4% and 48.6%, respectively). The radical scavenging activity against the DPPH radical was noteworthy with IC₅₀ values in the range of 5.6–62.9 µg/mL. The essential oils displayed minimum inhibitory and minimum bactericidal concentrations in the range of 4.6–37.5 µg/mL.