Chemical Composition and Insecticidal Activity of Origanum syriacum L. Essential Oil Against Sitophilus oryzae and Rhyzopertha dominica

Chemical profile, antibacterial and antioxidant properties of Rubia tinctorum L. essential oils

Plants have gained great importance. Secondary metabolites contribute to the drug discovery and development by their bioactive properties. Rubia tinctorum L. essential oil (EO) was obtained and analysed. Antioxidant and antibacterial activities were evaluated. The plant's EOs were obtained through steam distillation, and the compounds were identified using gas chromatography-mass spectrometry (GC-MS) analysis. DPPH free radical scavenging and ferric-reducing antioxidant power (FRAP) were employed to assess antioxidant activity. Total antioxidant capacity (TAC) was also presented. The disc diffusion method was employed for testing antibacterial activity. Cyclohexanone was identified as the predominant component in the EO, constituting 88.74% of the total composition. The EO did not show significant antioxidant capacity, while it demonstrated antimicrobial effect against Bacillus cereus ATCC 6633 (>13 mm of inhibition; 500 mg/mL) and Shigella ATCC 12022 (≥12 mm of inhibition; 500 mg/mL). R. tinctorum L. is new source of cyclohexanone.

Origanum syriacum L. (Za'atar), from Raw to Go: A Review

The interest in za'atar has increased in recent years due to its economic, cultural, and functional importance. The traditional za'atar mix made from dried Origanum syriacum is now a demanded product nationally and internationally. Air-drying at low temperatures can preserve za'atar quality traits better than other techniques such as oven-drying. The Palestinian za'atar market has the potential to develop and increase its value. However, it is facing many challenges. Another valuable product of za'atar is essential oil. Za'atar essential oil quantity and quality are affected by many factors including geographical location, cultivation, harvesting season, soil, extraction method, temperature, and others. These factors interact with za'atar and with each other; therefore, some factors are more effective than others and further research is needed to determine the optimum condition for producing and obtaining za'atar essential oil. Antimicrobial and antioxidant activities are the main functionalities of za'atar essential oil that are behind its medicinal importance. One hundred and twenty-one compounds have been identified in za'atar essential oil. The most common compounds are thymol, γ-terpinene, carvacrol, and α-pinene. The variation in the composition among za'atar essential oil samples results from the different conditions of the studies during za'atar growth as well as essential oil extraction.