Oil constituents of Artemisia nilagirica var. septentrionalis growing at different altitudes.

Oils of Artemisia nilagirica var. septentrionalis plants growing at different altitudes in Himachal Pradesh, India were hydro-distilled and analyzed by GC-GC/MS. The major constituents of the oil show variation with changes in altitude. At lower, middle and higher altitudes, the major constituents of the oil were caryophyllene oxide (28.6%), borneol (35.8%) and camphor (46.9%), respectively. The percentages of alpha-humulene and trans-beta-guaiene also increased, but the percentage of sabinene, trans-sabinene hydrate, 4-terpineol, caryophyllene oxide and humulene epoxide-II decreased with an increase in altitude. The characteristic compounds observed in the plants from lower altitudes were 2-hexene-1-ol, beta-thujone, thujanol, myrtenol and linalyl acetate, while the higher altitude plants were characterized by the presence of alpha-pinene, beta-pinene, limonene, linalool, gamma-gurijunene, germacrene-D and farnesol.