Supercritical fluid CO2 extraction of colchicine from colchicine Autumnele liliaceae.
Colchicine was successfully extracted from the corms of colchicine autumnele Liliaceae using supercritical fluid (SF) CO2. The pressure range used in the experiments was 20-40 MPa and the temperature was 40 degrees C. Being its high molecular polar, colchicine or other alkaloids are not easy to be extracted by SF CO2. In order to increase the mass transfer from the sample matrix to SF, different presoakers (such as methanol, ethanol, acetone etc.) were employed. Among the selected pre-soakers, best results were obtained with ethanol both in the aspects of yield and selectivity. At 35 MPa, 40 degrees C and with ethanol as pre-soaker, the yield was 1.8 mg/g, and the colchicine could be almost completely extracted from the sample matrix. The average concentration increased from 0.18% in natural sample to 6.92% in extract with SFE processing only once under the given conditions. The comparison of liquid ethanol extraction (LEE) and SFE showed that SFE is greatly superior to LEE in colchicine separation with SFE not only higher yield and selectivity but also a quick, safe and non-toxic method were obtained in colchicine extraction.
Fang
R
R
Chem. Dept., Yunnan University, Kunming, 650091.
Zhang
S
S
D002245:Carbon Dioxide / Q000737:chemistry*; D005591:Chemical Fractionation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D003078:Colchicine / Q000737:chemistry / Q000302:isolation & purification*; D019668:Liliaceae / Q000737:chemistry*
D002245:Carbon Dioxide; D003078:Colchicine