Supercritical Extraction and Identification of Bioactive Compounds in Dryopteris fragrans (L.) Schott

Background: This is a comparative metabolomic study of the medicinal plant Dryopteris fragrans (L.) Schott from the family Dryopteridaceae Herter (or Aspidiaceae Mett. ex Frank) growing under cold pole conditions in the Oymyakon region of the Republic of Sakha (Yakutia). Methods: The aerial parts of D. fragrans were subjected to extraction using supercritical CO₂ extraction and maceration methods. Several experimental conditions were investigated, including a pressure range of 50-300 bar and a temperature range of 31-60 °C. A 1% volume of ethanol was used as a co-solvent in the liquid phase of the extraction. Results: The most effective D. fragrans extraction conditions were 200 Bar pressure and a temperature of 55 °C. Tandem mass spectrometry was used to detect the target analytes. A total of 141 bioactive compounds (86 compounds from the polyphenol group and 55 compounds from other chemical groups) were tentatively identified in extracts of aerial parts of D. fragrans. Among these, thirty chemical constituents from the polyphenol group were identified for the first time. Other compound classes that were newly identified in D. fragrans include naphthoquinones (5,8-dihydroxy-6-methyl-2,3-dihydro-1,4-naphthoquinone, 1,8-dihydroxy-anthraquinone, 1,4,8-trihydroxyanthraquinone, chrysophanol, etc.), diterpenoids (tanshinone IIa, cryptotanshinone, isocryptotanshinone II, tanshinone IIb, etc.), polysaccharides, triterpenoids, and sesquiterpenes. Conclusions: These results highlight that D. fragrans is rich in bioactive compounds and put forward several newly detected compounds for further investigation.