Articles
THE INFLUENCE OF DISTRIBUTION OF ANTIMALARIAL CONSTITUENTS IN ARTEMISIA ANNUA L. ON TIME AND METHOD OF HARVEST
Article number
390_8
Pages
67 – 74
Language
Abstract
A field experiment in Tasmania studied the concentration profiles of artemisinin and a precursor artemisinic acid in the leaves of Artemisia annua L. from top to bottom of the plant and from the vegetative stage to full bloom.
In a Yugoslavian cultivar the artemisinin concentration decreased from top to bottom during the vegetative stages (0.12–0.05%) but increased from the bud stage to full bloom (0.08–0.12%). From the vegetative stage to early bud the concentration of artemisinic acid in the top quarter of the plant (1.00–1.28%) was about tenfold that of artemisinin but its concentration decreased from top to bottom of the plant at all growth stages.
Artemisinic acid can be chemically converted to artemisinin at about 40% efficiency.
In a Yugoslavian cultivar the artemisinin concentration decreased from top to bottom during the vegetative stages (0.12–0.05%) but increased from the bud stage to full bloom (0.08–0.12%). From the vegetative stage to early bud the concentration of artemisinic acid in the top quarter of the plant (1.00–1.28%) was about tenfold that of artemisinin but its concentration decreased from top to bottom of the plant at all growth stages.
Artemisinic acid can be chemically converted to artemisinin at about 40% efficiency.
These profiles of the antimalarial constituents suggested that is may be feasible to consider harvesting only the top half of the Yugoslavian cultivar at the early bud stage.
At this point 64% of the maximum potential artemisinin yield (direct and converted) at full bloom could be achieved for only 23% of the fresh plant yield.
A Chinese cultivar had a much more uniform distribution of artemisinic acid throughout the plant and this suggested that leaves from the whole plant should be harvested.
Authors
J.C. Laughlin
Keywords
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