Extraction of luteolin and apigenin from leaves of perilla frutescens (L.) Britt. with liquid carbon dioxide

Abstract

The extraction of luteolin and apigenin from the leaves of Perilla frutescens (L.) Britt. by liquid carbon dioxide (CO2) was carried out at 5, 20 and 25 °C. The extraction pressure was from 8.5 to 14 MPa. The extraction yields were compared with yields obtained by other solvent extraction methods, such as supercritical CO2 extraction and conventional aqueous alcohol extraction. We conducted qualitative and quantitative analyses for luteolin and apigenin in the extract by HPLC and analyzed the extraction behavior. The effect of two operating parameters, temperature and pressure of liquid CO2, on the extraction yield was investigated using the single-factor method. The yields of luteolin and apigenin in the extraction were significantly improved by the operating temperature, whereas a change in the selectivity of the extract was not observed.