[Studies on technology of supercritical-CO2 fluid extraction for volatile oils and saikosaponins in Bupleurum chinense DC].
OBJECTIVE
To study the technology of supercritical-CO2 fluid extraction (SFE-CO2) for the volatile oils and saikosaponins in Bupleurum chinense.


METHODS
Exploring the effects of pressure, temperature, extraction time, flow rate of CO2 and entrainers on the yield of the oils and saikosaponin-contained extracts; determining the optimum conditions for SFE-CO2; analyzing the oils by GC/MS and comparing the technology of SFE-CO2 with that of traditional steam distillation.


RESULTS
The optimum extraction conditions turned out to be--for volatile oils: pressure (EP) = 20 MPa, temperature (ET) = 30 degrees C, isolator I pressure (1P-I) = 12 MPa, temperature(1T-I) = 65 degrees C, isolator II pressure (1P-II) = 6 MPa, temperature (1T-II) = 40 degrees C, extraction time = 4 hours, and CO2 flow rate = 10-20 kg.(h.kg)-1 crude drug; for saikosaponins: EP = 30 MPa, ET = 65 degrees C, 1P I = 12 MPa, 1T I = 55 degrees C, 1P II = 6 MPa, 1T II = 43 degrees C, extraction time = 3 hours, entrainer = 60% ethanol, and CO2 flow rate = 20-25 kg.(h.kg)-1 crude drug.


CONCLUSIONS
SFE-CO2 excels the traditional steam distillation in raising yield and reducing extraction time. The oils are composed of 22 constituents including caproaldehyde, and the saikosaponins can only be extracted with the help of entrainers under higher pressure and temperature.
Ge
F H
FH
Guangzhou Pharmaceutical Industrial Research Institute, Guangzhou 510240, Guangdong, China.
Li
Y
Y
Xie
J M
JM
Li
Q
Q
Ma
G J
GJ
Chen
Y H
YH
Lin
Y C
YC
Li
X F
XF
D029972:Bupleurum / Q000737:chemistry*; D002245:Carbon Dioxide; D025924:Chromatography, Supercritical Fluid / Q000379:methods; D009822:Oils, Volatile / Q000302:isolation & purification*; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000302:isolation & purification*; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D012503:Saponins / Q000302:isolation & purification*
D009822:Oils, Volatile; D012503:Saponins; D002245:Carbon Dioxide; D009828:Oleanolic Acid; C025759:saikosaponin D