Chemical Composition and Anti-microbial Activity of Essential Oil from Aerial parts of Origanum vulgare L. from North-Western Himalayas

Origanum vulgare L. is an important aromatic medicinal plant, which has many medicinal properties and is used in the cosmetics and pharmaceutical industries. This study aims to evaluate the chemical composition and anti-microbial activities of essential oil extracted from aerial parts of a wild-growing O. vulgare L. The plant has been collected from the North-Western Himalayas region (Himachal Pradesh, India) and essential oil from its aerial part has been isolated through hydro-distillation. Gas chromatography/mass spectroscopy (GC/MS) analysis of the essential oil has been carried out to reveal its chemical composition. A total of twenty-four constituents have been identified, out of which eight constituents were different than reported in other studies, most probably due to geographical (height, temperature, soil, flora, and fauna) and geological (plants and animals) conditions. This essential oil has been dominated by oxygenated sesquiterpenes-38.08 %, followed by phenolic monoterpenoids-20.39 %, sesquiterpene hydrocarbon-14.4 %, monoterpene hydrocarbon-5.75 %, aliphatic alcohols-4.35 %, oxygenated monoterpene-3.99 %, polycyclic aromatic hydrocarbon-2.55 %, and sesquiterpenoid alcohol-2.26 %. Caryophyllene oxide (38.08 %) and thymol (20.39 %) have been found as major chemical components of essential oil. Anti-microbial activity of essential oil of O. vulgare has shown the highest zone of inhibition against the fungus Aspergillus niger (14 mm) and lowest against the Gram +ve bacteria Staphylococcus aureus (6 mm) at 600 ppm concentration among the all tested strains.