The influence of temperature in the production of Artemisinin in Artemisia annua L.

Abstract

Artemisia annua is a rich source of artemisinin, a sesquiterpene lactone proven Io effective in the control of the resistant strain ol the malaria agent Plasmodium. Secondary metabolism compounds, such as artemisinin, show changes in their contents when the plants come under the influence of environmental stress and variations. The scope of this work was to study the influence of temperature in the production of artemisinin in plants of hybrid CPQBA 2/39x1 V of A. annua. Plants of 88 days of age were cultivated in growing chambers, under two temperature levels. 11/20°C and 18/28°C, night and day, for 16 days. The artemisinin content in dry leaf mass was determined through by high performance liquid chromatography technique using ultraviolet detection. Other determinating parameters were dry leaf and stem mass, and artemisinin production by plant and the leaf stem relation. The average results were compared by t-student test. The lest at 18/28°C accumulated significantly more artemisinin than the 11/20°C treatment (p< 0.003). Significant differences were not found between lhe 18/28°C and 11/20°C treatments relating to dry leaf matter and artemisinin production by plant parameters. In plants submitted to the 18/28°C level, there was observed a significant reduction in dry stem mass (p<_0.024), and consequently, a significant increase in the leaf/stem relation (p<_0.008), when compared with the 11/20°C treatment plants. A greater leaf/stem relation is desirable in the A. annua industrial processing, in that the stem contains waxes which make more difficult the artemisinin isolation and purification.