Supercritical extraction of herbs I: Saw Palmetto, St John's Wort, Kava Root, and Echinacea

Extract yield and concentration of selected active components are presented for the supercritical extraction of dried Saw Palmetto berries, St John's Wort flowers and stems, Kava root and stems, and aerial portions of Echinacea purpurea using supercritical CO2, and CO2 + ethanol mixtures. Whole Saw Palmetto berries were obtained from America, and ground Kava root and stem from Fiji and Vanuatu. St Johns Wort and Echinacea were grown in New Zealand. Fatty acids and phytosterols were extracted from St Johns Wort at a total yield of 10 - 12% by mass. Kava lactones were obtained from Kava root at a yield of 3-8% by mass. The yield was highly dependent on the source and part of the plant used. Hyperforin, and plant waxes were recovered from St Johns Wort at a yield of 6-7% by mass. Hypericin was not extracted. Alkamides, plant waxes and other lipophilic solutes were extracted from Echinacea at a total yield of 2-3% by mass. Other desirable actives, such as chichoric acid and associated polyphenolic derivatives were not extracted. (C) 2002 Elsevier Science B.V. All rights reserved.