Assessment of radical scavenging capacity of Agrimonia extracts isolated by supercritical carbon dioxide

The results on the extraction of natural compounds from Agrimonia eupatoria and Agrimonia procera by using supercritical carbon dioxide (SC-CO2) are presented. Two agrimony species were extracted in laboratory scale equipment at various parameters and it was found that in case of A. eupatoria the increase in extraction pressure and the addition of a co-solvent ethanol remarkably increases the yield of the extracts, up to 4.25% at 25 MPa and 1% of ethanol. The highest yield from A. procera was 3.39% at the same conditions; however the dependence of pressure on extract yield was not so evident. In general, the extracts isolated at higher pressure were more effective free radical scavengers, although this dependence for some extracts, especially obtained from A. procera was rather complicated. The concentration of phenolics in A. eupatoria and A. procera SC-CO2 extracts was 2.3–8.3 and 2.5–7.1 mg/g, respectively. The compositions of SFE and organic solvent extracts were totally different.