Supercritical CO2 extraction of phenolic compounds from Baccharis dracunculifolia

Extracts from Baccharis dracunculifolia leaves were obtained using the following solvents: supercritical carbon dioxide (SC-CO2), ethanol and methanol. Supercritical extraction was carried out at temperatures of 40, 50 and 60 °C and pressures of 20, 30 and 40 MPa. Four phenolic compounds were analysed in the extracts by high-performance liquid chromatography: 3,5-diprenyl-4-hydroxycinnamic acid (DHCA or artepillin C); 3-prenyl-4-hydroxycinnamic acid (PHCA); 4-hydroxycinnamic acid (p-coumaric acid) and 4-methoxy-3,5,7-trihydroxyflavone (kaempferide). The global extraction yields (X0) obtained by the conventional methods with ethanol and methanol were higher than those obtained by SC-CO2. However on analysing the components of interest extracted at 60 °C and 40 MPa, the extraction yields of kaempferide, DHCA and PHCA were 156%, 98% and 64% higher, respectively, than in the ethanolic extracts. Only the p-coumaric acid extraction yield was better when extracted using the conventional method.

SC-CO2 at 40 MPa and 60 °C was more selective than alcohol to extract 3,5-diprenyl-4-hydroxycinnamic acid (DHCA or artepillin C); 3-prenyl-4-hydroxycinnamic acid (PHCA) and 4-methoxy-3,5,7-trihydroxyflavone (kaempferide) from Baccharis dracunculifolia leaves. The influence of temperature and pressure on extracts concentration can be seen in figure for the DHCA (known as artepillin C).Figure optionsDownload as PowerPoint slide