Preparation Of Ginsenoside F2 By Biotransformation

This paper is mainly about the biotransformation of Protopanaxadiol type ginsenoside to ginsenoside F2 by enzyme,and then prepare ginsenoside Rh2 group by the enzyme in ginseng plant.The high performance liquid chromatography analysis of the chromatographic conditions of the various ginsenosides was also established.At first,the conditions of high performance liquid chromatography separation of ginsenoside was determined,including the protopanaxadiol type ginsenoside,protopanaxatriol type ginsenoside,the ginsenoside of extract in red ginseng and ginseng liquid;the ginsenoside of Rg2?Rg3?Rhl?Rh2 group.In raw materials ginsenosides,Rd is the last one appeared in HPLC,the.retention time was 39.975min,so the method of shorter time detection was selected,and the ginseng extract and ginseng liquid both containe some rare ginsenoside which has low sugar moieties,so the concentration of acetonitrile needs improving and the detection time must prolong.Next,the two fungi whice can produce enzyme to transform F2 and their cultivating medium were compared.Sp.48 strain was choosed as the enzyme producing strain,and bean pulp was choosed as inducer.The optimal condition for enzymatic reaction was:the optimum substrate concentration was 5.0%,the optimum temperature was 40 ?,the optimum time was 12 h,the conversion rate of more than 80%.Beside ginsenoside F2,ginsenoside C-K was also produced.125 g hydrolysate can be obtained from 200 g of PPD as substrate.50 g of crude product was desugar by macroporous adsorption resin AB-8,decolored by ion exchange resin D296,and then further purified by silica gel column.4.19 g of ginsenoside F2 was obtained,and its purity was 96.7%based on HPLC.Therefore,the yield of F2 to raw PPD was 5.24%.The enzyme produced in ginseng plant used to prepare Rh2 group ginsenoside,5.9 g Rh2 was obtained,and its purity was 93.98%.Silica gel column was used to separated this product,0.38g mixture of Rh3 and Rk2 was obtained,the purity was 94%,Rh3:Rk2=65.5:34.5;2.56g pure Rh2 was obtained,purity was 98%,20(S)-Rh2:20(R)-Rh2=61.6:38.4.Finally,crystallization used to separated 20(S)-Rh2 and 20(R)-Rh2,1.22 g 20(S)-Rh2 was obtained With the purity of 98%,and its yield was 12.2%.