Hydrolyzing 20-O-Glycoside Of Ginsenoside By Bacterium

Ginsenoside Rg3 and Rh2 are improtant ingredients in ginseng,both of them belong to the protopanaxadiol type saponin(PPD),play important roles in anti-tumor and anti-cancer,Rh2,especially have the strongest physiological activity.What's more,protopanaxatriol saponins(PPT)such as Rg2 and Rh1,are responsible for the effect of inhibiting the growth of cancer cell.In this article,in order to transform the major protopanaxadiol type saponin and protopanaxatriol type saponin to rare ginsenoside like Rg3,Rh2,Rg2 and Rh1,a ginsenosidase from bacteria strains was studied,and the crude product were purified.First of all,to obtain a proper enzyme to transform glycoside of ginsenoside saponin,a kind of bacterium from Kaist(Korea)was studied in this experiment.The ginsenosidase was determined with TLC and HPLC while the ginsenoside Rb1,Rb2,Re and Rg1 were used as the substrate.TLC was used to detect the conditions of fermentation,such as types of inducer,the concentration of inducer,the optimal temperature and fermented time of the gisenosidase.The results showed that the optimal culture conditions for the Arthrobacter sp.No.3 GS0202 bacterium were in medium with 0.01%ginsenoside as inducer.For the PPD,the optimal temperature was 20 ? concentration was 0.1%,time were 12 h and 20 h for Rb1 and Rb2 respectively;for the PPT,temperature was 30 ?,concentration were 0.1%and 0.01%for Re and Rg1 respectively,time was 12 h and the transformation rate of Rh1 was 20%.Lastly,18.8 g the enzymatic reaction product containing ginsenoside Rg3 and Rh2 was separated by the AB-8 Diaion resin to remove the inorganic ion and sugar,further purified by the Silica Gel to obtain the high purity ginsenoside.While harvesting pure ginsenoside Rg33.2 g and Rh2 0.75 g,the result implicated that the yield of ginsenoside Rg3 and Rh2 was 17%and 4%respectively,and the purity of 20-(S)Rh2 was 80%.