COMPARISON OF EXTRACTION PROCEDURES FOR PARTHENOLIDE IN TANACETUM-PARTHENIUM

A comparison has been made of the efficiency of high performance liqui d chromatographic (HPLC) protocols and a human platelet-based bioassay to quantify parthenolide, a pharmacologically active sesquiterpenoid in Tanacetum parthenium (Feverfew). The optimum protocol, in terms bot h of concentration of parthenolide measured and of reproducibility of results, involved re-suspension of an acetone extract of the plant mat erial in 100% ethanol prior to isocratic HPLC. The mean parthenolide c oncentration in a leaf extract dissolved in ethanol from a glasshouse- grown clone (1.52+/-0.13%; n=10) was significantly greater (P=0.01) th an in an extract dissolved in acetonitrile (1.23+/-0.25%; n=10). progr essive reduction of the organic phase in the re-extraction solvent by replacement with phosphate-buffered saline resulted in concomitantly l ess parthenolide being measured in the samples. The mean parthenolide concentration measured by HPLC in extracts employing 3% ethanol in pho sphate-buffered saline as re-extracting solvent, as used previously in bioassays, was significantly (P<0.0001) lower than obtained with 100% ethanol. Parthenolide concentrations in extracts with 3% ethanol were also highly variable as reflected by coefficients of variance of up t o 15%. The protocol using 100% ethanol as re-extracting solvent was op timal for rapid and reproducible assessments of parthenolide content i n small (>20 mg dry weight) samples from glasshouse-grown and in vitro cultured materials of Feverfew.