Identification of volatile components in two Thymus species from Iran and their antioxidant properties

• Main Authors: Malekitabar, Elaheh, Nickavar, Bahman
• Format: Article
• Language: deu
• Published: Julius Kühn-Institut 2016-07-01
• Series: Julius-Kühn-Archiv
• Subjects: T. Pubescense; T. kotschyanus; antioxidant activity; essential oil; chemical composition; Labiateae
• Online Access: http://pub.jki.bund.de/index.php/JKA/article/view/6518/6113
• ISSN: 1868-9892; 1868-9892

Thymus species are well known to have significant amount of phenolic compounds and exhibit strong antioxidant activities. This study is designed to analyze the essential oils of two Iranian Thymus species, (T. kotschyanus Boiss. et Hohen and T. pubescense Boiss. et Kotschy ex Celak) obtained by hydrodistillation of aerial part of this plants, using GC-FID and GC/MS and evaluate the in-vitro antioxidant activities in two quantitative methods (namely DPPH. and ABTS.+ assay) to determine the total phenolic content of the species (assayed by colorimetric techniques) and to study the possible compositionantioxidant activity relationship. The major aroma constitutes in the essential oil of T. pubescense were found to be thymol (38.7 %), γ-terpinene (7.5 %), p-cymene (5.5 %), α-terpenyl acetate (3.8 %) and β-bisabolene (3.7 %) while in the essential oil of T. kotschyanus, -terpineol (16.9 %), 1,8-cineol (14.4 %), linalool (9.6 %), thymol (7.2 %) and geranyl acetate (5.4 %) were the main compounds. Both of the tested essential oils exhibited concentration-dependent antioxidant activity. T. pubescense showed more activity in both DPPH. [IC50= 285.2 (236.5-344.0) μg/mL] and ABTS.+ methods [IC50= 1.956 (1.810-2.113) μg/mL], as well as total phenolic content of T. pubescence [70254 ± 0.0049 μg/mg] was found to be slightly higher than T. kotschyanus [62933 ± 0.0026 μg/mg].