Effects of pressure variation and dynamic extraction time in supercritical fluid extraction (SFE) with co-solvent on bioactive compounds from Orthosiphon stamineus

Supercritical Fluid Extraction (SFE) is an advance method used in extracting bioactive compounds from plants. However, carbon dioxide used as an extraction solvent in SFE has limitation in extracting polar compounds. By adding a small amount of co-solvent (polar solvent) to extract wide range (polar to non-polar) of bioactive compounds, thereby affecting the extract yields. Pressure and dynamic time play important roles in this technique. In this study, the effects of pressure variation and continuous dynamic extraction time on the bioactive compounds from Orthosiphon stamineus, which were rosmarinic acid, 3'-hydroxy-5,6,7,4'-tetramethoxyflavone, sinensetin, and eupatorin using ethanol (co-solvent) modified CO2 SFE were discussed. The pressure variations studied were included 150, 225, and 300 bar with continuous dynamic extraction. The co-solvent used was 10% (v/v) of absolute ethanol with a flow rate at 4 mL/min. The quantification of bioactive compounds was done using HPLC. The variation of pressure and dynamic time significantly affected the total component yields of targeted bioactive compounds obtained after the extraction process, as it was increased along with increasing of extraction pressure and time. The total yields of bioactive compounds at different pressures were 4.08% (150 bar), 4.18% (225 bar) and 4.51% (300 bar). The application of SFE with co-solvent and the relationship with the yields of targeted bioactive compounds obtained from of O.stamineus were given.