Biotransformation And Preparation Of Ginseng Rg2(Group)

The paper is mainly about the study on production process of ginsenoside Re,optimum condition about the ginsenoside enzyme which was excreted by microorganism sp.39 enzymatic converse Re,Rg2 to Rgl,Rh1,respectively,and separation and purification of the mixture of ginsenoside Rg2,Rg4 and Rg6.Firstly,5g of ginsenosides extracted from the ginseng stems and leaves or the ginseng leaves were separated and the mixture of ginsenoside Re and Rgl were obtained through AB-8 macroporous adsorption resin,respectively.It showed that the optimum was 36.3%,35%ethanol solution for the separation,respectively.23.6g of ginsenoside Re were obtained from 50g of mixture of ginsenoside Re and Rgl after recrystallization,the recovery of ginsenoside Re was 47.2%.Then,in the suitable cultivation condition,microorganism sp.39 was cultivated to obtained the ginsenoside enzyme.The optimum conditions of enzymatic reaction were ascertained.In the optimum of pH6 and 0.2%ginsenoside Rg2,the ginsenoside Rg2 was almost transformed to ginsenoside Rhl by ginsenoside enzyme at 40? for 24h.In the optimum of pH6 and 1.0%ginsenoside Re,the ratio of transformation for Re was up to maximum by ginsenoside enzyme at 40 ? for 48h.And then,the mixture of the Rg2?Rg4 and Rg6 was used as raw material.Firstly,the AB-8 macroporous adsorption resin column which could separate ginsenoside Rg2 from the mixture was chose from AB-8 macroporous adsorption resin column and silica gel column,and the optimum condition of separation was studied,it was the ethanol solution with the concentration of 42%.Then,an experiment with 50g of mixtures and ethanol solution whose volumes were 9 times than column was experienced,the yield of Rg2 with the purity of 89.9%was 5g which was 10%of 50g.Finally,5g of mixtures,mainly ginsenoside Rg2,was used as crude sample for further purification and preparation of 20(S)-Rg2 and 20(R)-Rg2 from Rg2 by recrystallization,the recrystallization yielded 0.9g of 20(R)-Rg2,0.4g of 20(R)-Rg2,0.3g of 20(S)-Rg2,0.8g of 20(S)-Rg2 and 0.3g of 20(S)-Rg2 with the purity of 85%,97.1%,84%,84.6%and 82.9%after 5 times,respectively.The recoveries of these ginsenosides after recrystallization were 18%,8%,6%,16%and 6%,respectively.Finally,the preparative chromatography technology used for separation of ginsenoside Rg2(group)was investigated.The ginsenosides 20(S)-Rg2,20(R)-Rg2,Rg6,Rg4 were obtained with the the purity of 95.3%,96.4%,96.3%,98.3%,respectively.