Extraction of Volatile Oil and Saikosaponins from Bupleuri Radix with Supercritical CO{sub}2

摘要

The extraction of volatile oil with supercritical CO{sub}2 (SC-CO{sub}2) was investigated at temperatures ranging from 30°C to 50°C and pressures ranging from 15MPa to 30MPa. The experimental results show that the optimal extraction conditions for extraction of volatile oil are temperature of 50°C and pressure of 20MPa. The extraction yield under the optimal conditions is 2.56%. The absorbance of the extracts was detected by UV spectrophotometer. Under above operation conditions, the absorbance of the extracts can overpass the specified value of 0.625. Compared with steam distillation, the yield of the extract with SC-CO{sub}2 is higher. GC-MS analytical results indicate that the volatile oil extracted with SC-CO{sub}2 contains more compounds with higher boiling point. The extraction of saikosapnins (SS) is further studied with SC-CO{sub}2 in the presence of 95% ethanol-water solution as co-solvent at temperature of 65°C and pressure of 30MPa. The extracts were analyzed by HPLC. The experimental results show that, compared with water extraction followed by ethanol precipitation (WEEP), the yield with SC-CO{sub}2 is lower, but the extracts contain active components saikosapnin-d, which may be decomposed and can not be detected in the extracts by WEEP.