Essential oils of oregano are widely recognized for their antimicrobial activity, as well as their antiviral and antifungal properties. Nevertheless, recent investigations have demonstrated that these compounds are also potent antioxidant, anti-inflammatory, antidiabetic and cancer suppressor agents. These properties of oregano essential oils are of potential interest to the food, cosmetic and pharmaceutical industries. The aim of this manuscript is to review the latest evidence regarding essential oils of oregano and their beneficial effects on health.

https://www.mdpi.com/1420-3049/22/6/989/pdf

Essential Oils of Oregano: Biological Activity beyond Their Antimicrobial Properties

Essential oil diversity of European Origanum vulgare L. (Lamiaceae)

Interest in essential oils with pesticidal activity against insects and pests is growing. In this study, essential oils from different parts (leaves, twigs and seeds) of Cinnamomum camphora L. Presl were investigated for their chemical composition, and insecticidal and repellent activities against the cotton aphid. The essential oils, obtained by hydrodistillation, were analyzed by GC×GC-TOFMS. A total of 96 components were identified in the essential oils and the main constituents found in the leaves and twigs were camphor, eucalyptol, linalool and 3,7-dimethyl-1,3,7-octatriene. The major components found in the seeds were eucalyptol (20.90%), methyleugenol (19.98%), linalool (14.66%) and camphor (5.5%). In the contact toxicity assay, the three essential oils of leaves, twigs and seeds exhibited a strong insecticidal activity against cotton aphids with LC50 values of 245.79, 274.99 and 146.78 mg/L (after 48 h of treatment), respectively. In the repellent assay, the highest repellent rate (89.86%) was found in the seed essential oil at the concentration of 20 μL/mL after 24 h of treatment. Linalool was found to be a significant contributor to the insecticidal and repellent activities. The results indicate that the essential oils of C. camphora might have the potential to be developed into a natural insecticide or repellent for controlling cotton aphids.

https://www.mdpi.com/1420-3049/21/4/423/pdf

GC×GC-TOFMS Analysis of Essential Oils Composition from Leaves, Twigs and Seeds of Cinnamomum camphora L. Presl and Their Insecticidal and Repellent Activities

The composition of the essential oil and aqueous distillate of Origanum vulgare L. growing in Saudi Arabia and evaluation of their antibacterial activity

Supercritical fluid extraction of essential oil from Leptocarpha rivularis using CO2

Origanum vulgare L., Lamiaceae, from six different production areas of China and Pakistan were analyzed via gas chromatography equipped with a flame ionization detector (GC-FID) and examined for their volatile constituents by gas chromatography-mass spectroscopy (GC-MS). This procedure allowed the identification of 11 to 46 components among six production areas, representing 98.5% to 99.9% of the total oil extracted. The yields of the essential oil of the six production areas of O. vulgare ranged from 0.1 to 0.7%. The class of oxygenated monoterpenes was predominant in all the essential oils. However, samples S5 and S6 have high content of sesquiterpene hydrocarbons (33.7 and 43.7%); while sample S6 is high on oxygenated sesquiterpene (32.9%). The principal component analysis of O. vulgare was employed to provide a comprehensive evaluation of essential oil components. The cluster analysis of O. vulgare was classified into three subsets, characterized according to the major essential oil components. The current study investigated the composition differences of essential oil among six production areas offering foundation for quality control, resource optimization, and clinical treatments.

/pdf/analysis-of-essential-oils-of-origanum-vulgare-from-six-1on56s2r5b.pdf

H.Y. Gong

Papers

Analysis of essential oils of Origanum vulgare from six production areas of China and Pakistan