The Low-cost Fermentation Of Ginsenosidase Type Ⅰ And The Crystallization Of C-K

Ginseng is a famous herbal medicine in our country.Ginsenoside is the major active ingredient in ginseng,and it has high pharmacology value.After oral intake of ginseng,the protopanaxadiol type ginsenosides(PPD)are hydrolyzed in the human intestinal tract into the more active minor ginsenoside C-K.C-K has special physiological and therapeutic activities that are readily used for ginseng medicines and health foods.Biotransformation that is used to transform protopanaxadiol type ginsenosides(PPD)into C-K has great significance.The main idea of this paper is to screen the enzyme producing strain,and optimize the culture medium and the conditions of fermentation.The sp.48 strain was choosed as the enzyme producing strain and sophora flower was used as the inducer in this research.The optimum reaction temperature was 45℃.The massive enzyme reacted in the large-scale reactor,and the substrate concentration increased to 6%,the reaction time was 48 h at 45℃.The produce rate of C-K was above 80%.The enzyme product 335 g was separated by macroporous absorbitive resins(AB-8)and ion exchange resins(D-296),and dried in the hot water pot.The extraction of raw C-K was 253 g,the yield was 75.5%.Then it was purefied by the silica gel column.The best mobile phase was the mixture of V(chloroform):V(methanol)= 9:1.The extraction of puritied C-K was 16.2 g,the yield was 32.4%and the purity of product was 90.8%.Finally,13.8 g pure C-K product was obtained by crystallization method with a purity of 98.9%based on HPLC method.Therefore,the yield from the crude product to the C-K standard was 20.8%.The structure of product was determined as C-K(20-O-β-D-glucopyranosyl-20(S)-protopanaxadiol)by 13C-NMR.