Essential Oil Composition and Antioxidant Activities of Alkanet (Alkanna tinctoria subsp. tinctoria)

Abstract

This study is designed to examine the chemical composition and in vitro antioxidant activity of the hydrodistillated essential oil and the various extracts of alkanet (Alkanna tinctoria subsp. tinctoria). Gas chromatography (GC) and GC-mass spectrometry (GC-MS) analysis of the essential oil were resulted in the determination of 27 different compounds, representing 93.32% of the total oil. The major compounds detected in the oil, were pulegone (22.27%), 1,8-cineole (13.03%), alpha-terpinyl acetate (6.87%), and isophytol (6.83%), respectively. Antioxidant activities of thy samples were determined by 4 different test systems namely beta-carotene/linoleic acid, 1,1-diphenyl-2-picrylhydrazyl (DPPH), reducing power, and chelating effect. In all systems, essential oil showed the weakest activity profile. On the other hand, ethyl acetate and water extracts exhibited excellent antioxidant activities. As well as the antioxidant activities of the extracts, they were evaluated in terms of their total phenolic and flavonoid contents. In parallel to the experiments, ethyl acetate and water extracts were found to be rich-in these phytochemicals.