The content of parthenolide and its yield per plant during the growth of Tanacetum parthenium

During the growth of Tanaceum parthenium (L.) Schultz-Bip. Feverfew, Asteraceae) the percentage of parthenolide was the highest at an early stage (just before the formation of stems). The yield of parthenolide per individual plant gradually increased from about 10 mg at the beginning of the study to about 20 mg when the plant was in full bloom. Parthenolide was present in the leaves and flowerheads, but not in the stems. Drying at ambient temperature and lyophilisation had no negative influence on the yield of parthenolide per individual plant on comparing the results with those of fresh plant material. Based on the results of this study and on data from the literature we propose to distinguish two qualities of feverfew: a: Tanaceti parthenii folium (feverfew leaf), harvested at an early stage before the formation of the stems and b: Tanaceti parthenii herba (feverfew herb), harvested at full bloom, with a minimum parthenolide content of 0.50% and 0.20%, respectively, calculated on a dry weight basis. Both drugs can be easily distinguished by means of microscopic examination.