Abstract:
The supercritical CO2 fluid extraction (SFE) procedure for free anthraquinones from polygonum cillinerve(Nakai) Ohwi was studied. The contents were determined by magnesium acetate-colorimetry. The influences of extraction temperature, extraction pressure, static extraction time, volume of entrainer, maceration, and the times of repeated extracting on extracting efficiency were investigated. The results showed that the sample (200 mg) should be macerated in 10 mL water for 24 h before SFE．The optimal extraction parameters were temperature 45℃, pressure 35 MPa, 15 mL of ethanol as modifiers，static extracting 35 min and dynamic extracting 30 min, repeated extracting 3 times, respectirely. Contents of free anthraquinones，emodin and physcion obtained by SFE were 3.98%, 3.44% and 0.38%, respectively. Compared with sonication extraction, supercritical CO2 extraction has the advantages of high yield，environment-friendly property and fewer residual solvent．
