The essential oil characterization of Achillea millefolium var. occidentalis DC. from the Great Basin of North America

Abstract

Article InformationAchillea millefolium is native to temperate regions of the northern hemisphere and is important in traditional herbal medicines throughout its range. The purpose of this work is to evaluate the essential oil composition of the North American variety, A. millefolium var. occidentalis, and to test the hypothesis that var. occidentalis has a chemical composition different from Old World A. millefolium. Six samples of A. millefolium were collected from different locations in the Great Basin region of eastern Oregon and southern Idaho. The essential oils were obtained by hydrodistillation and analyzed by gas chromatographic methods. The essential oils showed wide variation in composition with the major components (-)-camphor (0.5-59.6%), (-)-α-thujone (0.0-40.5%), terpinen-4-ol (0.9-23.4%), artemisia ketone (0.0-18.7%), 1,8-cineole (5.3-16.4%), and (+)-(E)-nerolidol (0.4-13.5%). The essential oil compositions of western North American A. millefolium cannot be distinguished from the samples from Old World samples of A. millefolium; there is no phytochemical support for infraspecific differentiation of the North American variety.