Chemical composition and antioxidant activity of the essential oil of Clinopodium vulgare L.

Abstract

This study was designed to examine the chemical composition and in vitro antioxidant activity of the essential oil of Clinopodium vulgare. GC-MS analysis of the oil resulted in the identification of 40 compounds, representing 99.4% of the oil; thymol (38.9%), gamma-ter-pinene (29.6%) and p-cymene (9.1 %) were the main components. The samples were subjected to a screening for their possible antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and beta-carotene-linoleic acid assays. In the first case, IC50 value of the C. vulgare essential oil was determined as 63.0 +/- 2.71 mu g/ml. IC50 value of thymol and gamma-terpinene, the major compounds of the oil, was determined as 161 +/- 1.3 mu g/ml and 122 +/- 2.5 mu g/ml, respectively, whereas p-cymene did not show antioxidant activity. In beta-carotene-linoleic acid system, C. vulgare essential oil exhibited 52.3 +/- 1.19% inhibition against linoleic acid oxidation. In both systems, antioxidant capacities of BHT, curcurnine and ascorbic acid were also determined in parallel experiments. (c) 2006 Elsevier Ltd. All rights reserved.