| In this paper the ultrahigh pressure extraction (UPE) of ginsenosides from Panax ginseng root was studied. The operation parameters of UPE, such as extraction pressure, extraction time, solvent kind and concentration, the ratio of solvent to material, were examined emphatically. The extraction results of UPE were compared with soxhlet, heat reflux, ultrasound, microwave and supercritical CO2 extraction. The microcosmic mechanism about UPE was also studied in this paper. In this paper the main contents of research and results are as follow: 1. The essential components of two products which obtained by the UPE and the conventional reflux extraction respectively were analyzed by HPLC, ESI-MS and FTIR. As a result, they contain totally same ginsenosides molecules. So it could be deduced that the extraction of ginsenosides from Panax ginseng root by UPE is reasonable. It is the first time to determine the effect of ultrahigh pressure on the molecule structure of the essential components of plant extractions, and it is confirmed that the product of UPE has no different of conventional extraction by chemical evidence and spectrum analysis. 2. The process of ultrahigh pressure extraction had been studied roundly, the results are as follow: ①The 30～50% ethanol-water (v/v) is the best suitable extraction solvent to extract ginsenoside from Panax ginseng boot. Within 0～70% of ethanol concentration, the extraction yield of ginsenosides is increase as increasing of the ethanol concentration. When the concentration of ethanol is larger than 70% (v/v), the extraction yield of ginsenoside would decrease slowly with increasing of the ethanol concentration. ②The optimal pressure to extract ginsenosides is 100～200MPa. When the pressure is changed between 100 MPa and 500 MPa, the extraction yield of ginsenosides would increase with increasing of pressure, but the increasing extent is small. When the pressure is beyond 500 MPa, the yield is decrease slightly. The lower pressure should be chosen to save the investment of ultrahigh pressure equipment. ③The optimal ratio of solvent to material of ultrahigh pressure extraction of ginsenosides is 50/1 to 100/1. The extraction yield of ginsenosides increase with increasing of the ratio of solvent to material, but more solvent would be consumed while the ratio is large. When the ratio of solvent to material is higher than 100/1, the extraction yield of ginsenoside is decreased slowly with increasing of the ratio of solvent to material. ④The optimal extracting time of UPE is 2 min. Under the high pressure the diffusion speed is very great, and in a very short time the solubility and diffusion in the inner and outer cells get balance. And the solubility will be the maximum value. 3. Uniform experiments of UPE of ginsenosides from Panax ginseng root are done in the batch ultrahigh pressure extraction equipment. Interaction orthogonal table U10(103) is used to study the effects of extraction pressure, concentration of solvent, and the ratio of solvent to material and their interactive effects on extraction yield of ginsenosides. Experimental results showed that the effect of concentration of solvent on extraction yield is the most significant factor, and the relationship of extraction yield of ginsenosides with the operation parameters of UPE can be described by following equation: Y=0.3417486 + 0.0008669P+0.0066393V + 0.0038203R –0.0000005P2 + 0.0000001PV –0.0000091 PR -0.000093 V2 + 0.0000242VR According this equation, the optimum extraction conditions to extract Ginsenoide-Re by UPE are as follows: (I) the ethanol concentration is 50%; (II) The ratio of solvent to material (ml/g) is 100/1; (III) Pressure is 200MPa. The forecast yield of ginsenoside-Re (%) of HPE is in the range of 0.3828% to 0.9159%. It was proved by experiments. The optimum extraction process of UPE ginsenosides is established first time in this paper. 4. In the experiments, the same sample powder of Panax ginseng root was used, and same HPLC analysis was done. The optimum extraction process of soxhlet extraction, heat reflux extraction, ultrasound extraction, microwave extraction and supercritical carbon dioxide extraction ginsenosides from Panax ginseng root were established, and their extraction yields were compared. Results showed that all the extraction method could be used to extract ginsenosides except supercritical carbon dioxide extraction. 5. Comparison of UPE with other extraction method is shown as follow, every...
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