Effect of method of distillation on the yield and chemical composition of Artemisia annua essential oil

Flowering shoot biomass of Artemisia annua var. Jeevanraksha grown under the semi-arid tropical climate of Hyderabad, South India, and distilled by field- and hydro-distillation techniques produced 0.26% and 0.35% essential oil yields on a fresh weight basis, respectively. Gas chromatography-flame ionization detector (GC-FID) and GC/mass spectrometry (GC/MS) analyses yielded fifty-four constituents accounting for 95.8% and 92.0% of the oils in field and hydro-distillations, respectively. The major compounds of the field-distilled oil were: camphor (23.6%), beta-caryophyllene (16.6%), alpha-humulene (5.4%) and germacrene D (17.0%). The principal components of the hydro-distilled oil were: 1,8-cineole (11.1%), camphor (36.6%), beta-caryophyllene (5.7%) and germacrene D (5.9%). Aliphatic ketones (37.7%), monoterpene hydrocarbons (11.2%) and oxygenated monoterpenes (19.9%) were higher in the hydro-distilled oil. Sesquiterpene hydrocarbons (54.1%) and oxygenated sesquiterpenes (6.8%) were present in large amounts in the field-distilled oil.