[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. METHOD: 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. RESULT: 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. CONCLUSION: 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.

[Studies on the chemical constituents of Excoecaria cochinchinensis Lour. var. viridis Merr].

Eight compounds have been obtained from the root and stem of Excoecaria cochinchinensis var. viridis growing in Tonghai county of Yunnan province. According to their spectroscopic analyses and physicochemical constants, they have been identified as: shikimic acid, 1-cyclohexene-1-carboxylic acid-5-hydroxy-3,4-isopropylidene-dioxy, oxy-bis(5-methylene-2-furaldehyde), beta-sitosterol, tetracosanoic acid, palmic acid, steric acid and hentriacontane.