Supercritical carbon dioxide extraction and fractionation of hyper for in and adhyperforin from St. John's Wort (Hypericum perforatum L.)

Abstract

Plants of the genus Hypericum have been used as traditional medicinal plants in various parts of the world. St. John's Wort (Hypericum perforatum L.) has been reported as an antidepressive, antiviral, antimicrobial, anti-inflammatory, and a healing agent. Thus, extraction with high yields of total extract and high contents of the pharmacological active compounds is desired. St. John's Wort was extracted with supercritical carbon dioxide using a small batch extraction plant. The effects of pressure and temperature were examined with respect to extraction yield of total extract as well as content of two phloroglucinols (hyperforin and adhyperforin). Extracts were analyzed using a highly selective LC/MS/MS method. Applied method of extraction of St. John's Wort was compared with ultrasound extraction with methanol. Supercritical carbon dioxide extraction is showing high selectivity for phloroglucinols. Within the studied range of extraction (pressure: 100, 150, and 200 bar; temperature 40 and 50°C ) a high content of the two phloroglucinols in the resulting extracts was obtained (up to 52%). An increase of extraction temperature showed a negative effect, leading to increased degradation of hyperforin and adhyperforin. Additional, a fractionation of the supercritical carbon dioxide was performed at 100 bar and 40°C. The fraction 250-450 g of consumed CO2 gave the highest content of hyperforin and adhyperforin in extract (up to 54%, for hyperforin).