Chemical Composition and Antioxidant Activity of Origanum elongatum Essential Oil

Abstract

Background: In recent years, antioxidants have become essential in nutrition because of their ability to protect the body against oxidative cell damage that can produce dangerous diseases. Medicinal plants are a major source of many bioactive molecules that act directly on the body.Objective: The main objective of our work is to highlight the antioxidant potential of the essential oil (EO) of Origanum elongatum Emb and Maire (endemic plant of Morocco), determine its composition, and carry out fractionation operations to isolate the molecule (s) responsible for this activity.Materials and Methods: The measurement of the antioxidant activity of the EO is carried out by trapping the free radical 2,2‑diphenyl‑1‑picrylhydrazyl and the composition of the EO is determined using gas chromatography coupled with mass spectrometry. The fractionation of the EO was carried out by various chromatography techniques.Results: The results show that the EO has an interesting antioxidant activity with an EC50 in the order of 1.2 in comparison with a reference antioxidant, δ‑tocopherol whose EC50 is 0.26. The EO of O. elongatum consists of 11 compounds, of which 3 are the majority: carvacrol (60.42%), para‑cymene (13.9%), and γ‑terpinene (9.4%).Conclusion: Fractionation of the oil made it possible to isolate a purified antioxidant molecule consisting mainly of carvacrol (95%).

Keywords: 2; 2‑diphenyl‑1‑picrylhydrazyl; Antioxidant activity; Essential oil composition; Fractionation; Origanum elongatum