The extraction of vindoline from Catharanthus roseus using the supercritical carbon dioxide was performed in various temperature and pressure conditions. Since carbon dioxide is structurally stable and nontoxic, it was chosen as a supercritical solvent. The experimental apparatus consists mainly of four parts; the gas supply, the cosolvent supply, the extractor and the separator. Complex indole alkaloids were extracted from the leaves or the stems of Catharanthus roseus in the operating range 35~70℃ and 100~300bar. The leaves and the stems of Catharanthus roseus were dried for 24 hours in a oven and then ground to the powders. Both the sample powders and the beads (diameter 3mm, glass) were charged together in the extractor to increase mass transfer efficiency between solid particles and a carbon dioxide. The extracts were analyzed by HPLC and LC/MS spectroscopy and also the results were compared with the results obtained by the solvent extraction method.
Additionally, the extraction using the supercritical carbon dioxide with ethanol as a cosolvent was also carried out in various temperature and pressure conditions and the contents of vindoline in the extracts were determined by HPLC. In this experiments, the flow rate of ethanol was 20.4㎕/min, about 3wt.% of flow rate of supercritical carbon dioxide. However the effect of ethanol on the yield of extracted vindoline was not significant.
In summary, the technique of extraction of vindoline from Catharanthus roseus using the supercritical carbon dioxide was better selective for vindoline and simpler in process than that of solvent extraction.
