Tocopherol and tocotrienol homologue recovery from Hypericum perforatum L. and extraction residues after hydroethanolic extraction
Paweł Górnaś, Inga Mišina, Danija Lazdiņa
Abstract
Hypericum perforatum L. (St. John’s Wort) is a medicinal herb used in traditional and modern phytochemical drugs. Usually used to produce phloroglucinol (hyperforin, adhyperforin), naphtodianthrone (hypericin) and xanthone compound extracts for cosmeceuticals and the treatment of mild-moderate depression. The present study shows that H. perforatum inflorescences extracts contain tocopherols (Ts) and rare nature tocotrienols (T3s). To demonstrate that is high probability of the presence of tocotrienols in pharmaceutical products obtained from St. John’s Wort by hydroethanolic solutions, several hydroethanolic extracts (40.0–96.2 %) of H. perforatum inflorescences was obtained. To show that H. perforatum residues can still be a valuable source of tocotrienols after 1st extraction, several extracts using 96.2 % ethanol were produced. From eight tocochromanols present in H. perforatum inflorescences, the extracts contained mostly δ-T3, followed by α-T and α-T3. The 40.0 % and 50.0 % ethanol extracts contained trace amounts of only δ-T3, and the extractability of tocochromanols increased along with the ethanol ratio. Re-extraction in 96.2 % ethanol allowed for complete recovery of δ-T3 from St. John’s Wort. Residues of 1st extraction by hydroethanolic solutions below 70.0 % were a good source of tocotrienols which were successfully re-extracted by using 96.2 % ethanol with the assistance of ultrasound treatment. The present study demonstrated that the pharmaceutical value of H. perforatum is higher than estimated due to the presence of tocotrienols with high bioactive potential, multi-purpose potential of St. John’s Wort biomass, processing chain value improvement (multi-step extraction of bioactive compounds) and reduction of ethanol consumption. • St. John's wort ( Hypericum perforatum ) is a novel source of tocotrienols. • Tocotrienols (T3s) are extractable in hydroethanolic solutions (50.0–96.2 %, v/v). • Tocochromanol homologues are differently recoverable in hydroethanolic solutions. • 96.2 % ethanol recovers 103 ± 5 % of δ-T3 and 76 ± 7 % of α-T3 from H. perforatum . • < 70 % ethanol hydroethanolic extraction residues are prospective sources of T3s.