Extraction of hyperforin and adhyperforin from St. John's Wort ( Hypericum perforatum L.) by supercritical carbon dioxide

Abstract

St. John's Wort ( Hypericum perforatum L.) was extracted with supercritical carbon dioxide (SC CO 2) under 10, 15 and 20 MPa and at 313 and 323 K. The influence of SC CO 2 density (400–800 kg/m 3) was examined with respect to extraction yield as well as to hyperforin and adhyperforin content, which was determined using a highly selective LC/MS/MS analytical method. A high concentration (up to 526 mg/g total extract) of two phloroglucinol derivatives was determined in this study showing that the absolute extracted amount of hyperforin and adhyperforin (mg per 1 g of dry plant) is almost constant not depending on total yield of extract, i.e. on density of SC CO 2. Determination of the rate of hyperforin and adhyperforin extraction at 313 K and 10 MPa showed that the maximal rates correspond to consumption of 7–8.5 g of CO 2 per 1 g of dry St. John's Wort. Investigation of ultrasonic extraction of St. John's Wort followed after pre-treatment of plant material (323 K; 10 MPa; 2 h; without CO 2 flow) indicated that obtained extract contains a higher amount (mg/g plant material) of two most important pharmacological active compounds of St. John's Wort, hyperforin and hypericin, than the extract obtained by ultrasonic extraction only.