Chemical characterization of the essential oil compositions and antioxidant activity from Iranian populations of Achillea wilhelmsii K.Koch

To evaluate the chemical composition and the antioxidant activity of the essential oils from Iranian yarrow (Achillea wilhelmsii K.Koch), twenty accessions were collected from their natural habitats throughout southwest Iran. Essential oils were obtained by using a Clevenger-type apparatus, and were then chemically characterized by gas chromatography (GC) and gas chromatography with mass spectrometry (GC–MS) methods Essential oil yields ranged from 0.14% to 0.44% (w/w) and 54 components were identified in the samples. The main components were found to be chrysanthenone (38.8%), trans-carveol (27.5%), linalool (26.1%), neoiso-dihydrocarveol acetate (25.2%), camphor (19.9%), filifolone (19.7%), 1,8-cineole (16.7%), borneol (13.6%), a-pinene (11.8), trans-piperitol (11.7%), (E)-caryophyllene (11.2%), (E)-nerolidol (10.8%), and lavandulyl acetate (10.0%). The volatile composition of the yarrow accessions was analyzed using hierarchical cluster analysis. The yarrow populations fell into five chemotypes based on essential oil constituents. The antioxidant activity was evaluated using DPPH radical sequestering method (IC50 = 129-372 mg/ml). Results showed a significant variation among accessions with regard to quality and quantity as well as biological activity of essential oils due to genetic makeup, environmental specifications, physiological conditions of the sampled plants and interaction between them. The current research provided new insights into the chemical variation of this species together with a possible application of its essential oil as a natural preservative agent in food and pharmaceutical industries.