Characterization of the Essential Oil ofArtemisia annuaL.

Abstract
A germplasm collection of Artemisia annua L. consisting of 13 accessions was field grown. The essential oil, which was obtained from dry leaves and flowers by hydrodistillation was analyzed by GC and GC/MS for essential oil composition. The oil content of leaves ranged from 0.84% to 1.51% (volume/dry weight) with individual plants as high as 2.35%. Thirty-two constituents were identified in the oil of the leaves and flowers, and the greatest concentration of oil was found in fully mature leaves (47% total oil/plant), the middle third portion of the foliage. The major components of the oil include: artemisia ketone (35.6%) and 1,8-cineole (28.1%) in the leaves of early summer harvested plants, artemisia ketone (26.8%) and camphor (20.5%) in leaves of fall harvested plants, and artemisia ketone (56%) and camphor (10.5%) in flowers of fall harvested plants. Certain accessions which were rich in specific constituents (as % of essential oil) were identified, e.g., artemisia ketone (68.5%), camphor (27.5%), 1,8-cineole (22.8%), α-pinene (16.0%) and camphene hydrate (12%). Plants within accessions also varied in essential oil composition.