Chemical Composition and Biological Activities of Volatile Oils in Different Periods of Growth of Artemisia annua L. from China

Artemisia annua L. has been widely used as an antimalarial herbal medicine in China. The volatile oils of A. annua are also the main active substances, but the volatile oils in different growing periods has short of systematic research. This paper researched on chemical composition, antioxidant and antimicrobial activities of volatile oils in four different periods of growth of A. annua from Cliina. Results shown that the volatile oil of.4. annua in the flowering stage increased to 0.8 %. According to GC-MS analysis. 21,23,21 and 22 components were identified in the pre-flowering, initial flowering, flowering and post-flowering stages, representing 93.9 %, 95.3 %, 97.1 % and 90.6 % of the total detected constituents, respectively. For the chemical classification of volatile oils, the total hydrocarbon content decreased, while the total oxygenated compounds increased significantly from the pre-flowering stage to the post-flowering stage. Antioxidant activity of volatile oils in the flowering and post-flowering stages were stronger than that in pre-flowering and initial flowering stages. According the in vitro tests of inhibitory bacteria, the essential oils had different inhibitory effects on Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Salmonella typhimurium. Through this study, we understand the volatile oil of A. annua changes accumulated in different growth stages, can be advantageous to the oils exploitation.