Gas chromatography-mass spectrometry investigation of the volatile components of Artemisia annua L.
Artemisia annua L., annual wormwood, is an aromatic herb of Asiatic and Eastern European origin that has also become naturalised worldwide. The plant is known as the only source of the traditional Chinese herbal medicine Qing Hao, which has been used for over 2000 years to alleviate fevers (1). The species received considerable attention because of its antimalarial properties. The plant activity has been established to be due to artemisinin (qinghaosu) a cadinene – ; ; ; type sesquiterpene lactone endoperoxide, present in the aerial parts. A. annua is also valued for its essential oil of which the characteristic sweet aroma has been described as grassy, fresh and bitter with camphoraceous nuance. The essential oil composition has been studied thoroughly and about 60 components were identified. Artemisia ketone, camphor, germacrene D and 1, 8-cineole are usually the main components. If the oils are grouped according to geographical origin the following groups can be established: chemotype 1, with 33-75% artemisia ketone and 15-56% artemisia alcohol, chemotype 2, with 9-22% camphor and 4-19% germacrene D, chemotype 3, with 64% artemisia ketone, 5-15% 1, 8-cineole, 4-16% a-pinene and germacrene D, and chemotype 4 with 37-53% artemisia ketone.