Chemical variation in the essential oil of Ephedra sinica from Northeastern China

Hydro-distillated volatile oils of Ephedra sinica Stapf. from six populations of Inner Mongolia in Northeastern China were analyzed by using GC/MS. Ninety-nine compounds were identified in the oils and a relatively high variation in their contents was found. The main constituents of the essential oils were alpha-terpineol (19.28-52.23%), p-vinylanisole (0.59-11.64%), 3-methyl-2buten-1-ol (0-5.44%), tetramethylpyrazine (0.63-8.99%), terpine-4-ol (1.17-4.37%), alpha-linalool (1.62-5.15%), phytol (1.2415.73%), gamma-eudesmol (0-7.77%), and eudesm-7(11)-en-4-ol (0.41-6.13). Six populations were divided into two chemotypes based on cluster analysis and principal component analysis (PCA); one rich in alpha-terpineol and p-vinylanisole, and the other rich in phytol, gamma-eudesmol, and eudesm-7(11)-en-4-ol. (c) 2005 Published by Elsevier Ltd.