Extraction and quantification of some valuable flavonoids from pinecone of Pinus brutia via Soxhlet and Supercritical CO2 extraction: a comparison study

In this study, the extraction of oil from pinecone of Pinus brutia was evaluated by supercritical CO2 (Sc-CO2) and Soxhlet extraction methods. The quercetin, rutin and kaempferol (QRK) contents of oil were analyzed one by one via HPLC. The rutin compound investigated in this study has the potential to be a drug against the COVID 19 virus. SEM and BET analysis were performed to observe the structural change and increase in surface area after Sc-CO2 extraction. The operating conditions were investigated in the range of 35-65 degrees C temperatures, 140-220 bar of pressures, 0.30-1.00 mm of mean particle sizes, 3-71/min of CO2 flow rates, 0-8% w/w co-solvent and 30-150 min extraction periods. When the results obtained by the Sc-CO2 method were compared with the results of Soxhlet extraction method, the maximum recovery of total QRK was found 4.18% in co-solvent-free studies and 30.94% in co-solvent-added Sc-CO2 studies. Sc-CO2 extraction results of Q, R, and K were found as 14.75 +/- 1.08 mu g/g, 14.23 +/- 1.27 mu g/g, and 15.70 +/- 1.13 mu g/g pinecone, respectively. Soxhlet extraction results of Q, R, and K were found as 36.43 +/- 2.26 mu g/g, 57.19 +/- 3.81 mu g/g, and 50.80 +/- 2.79 mu g/g pinecone, respectively. The maximum amount of QRK was found as 44.68 +/- 2.89 mu g/g pinecone by Sc-CO2 method via adding 8% ethanol by mass and as 144.42 +/- 5.39 mu g/g pinecone by Soxhlet method. According to the reference Soxhlet method efficiency, the Sc-CO2 extraction recovery was found as 30.94%. [GRAPHICS] .