Distribution of artemisinin and bioactive flavonoids from Artemisia annua L. during plant growth

Artemisia annua L. (Qinghao, Asteraceae) is a promising and potent antimalarial herbal drug. Its activity has been ascribed to the content of artemisinin, a sesquiterpene lactone that is very effective against drug-resistant Plasmodium. Many studies have pointed out that the presence of polymethoxyflavonoids in the phytocomplex can enhance the bioavailability or the activity of artemisinin. In this study the production of both artemisinin and flavonoids by plants of an aromatic ecotype of A. annua L. was characterized in different aerial parts of the plants at different developmental stages. The qualitative profile of the investigated plant parts was similar; in addition to artemisinin, four flavonoids were identified: chrysoplenctin, casticin, eupatin and artemetin. The highest contents of both flavonoids and artemisinin were found at the full blooming stage. At this developmental stage, artemisinin was higher in leaves than in inflorescences, while the total flavonoid levels were similar in both plant organs. (C) 2007 Elsevier Ltd. All rights reserved.