Preparation Of Rare Ginsenosidases Such As C-Mc From PPD Through The Method Of Enzyme Conversion Produced By Aspergillus Sp.48 Strain

This paper studies the method on the biotransformation of rare ginsenosides C-Mc,C-K,C-Y,F2 and GypLXXV from the Protopanaxadiol type ginsenosides(PPD)by enzyme that produced from Aspergillus sp.48 strain and the transformation of ginsenoside F2 hydrolased into ginsenosides Rh2 group by ginseng extract compound enzyme.The structure of rare ginsenoside C-Mc was identified by NMR.Aspergillus sp.48 strain was cultured to obtain the enzyme for preparing rare ginsenosides.After testing on the enzyme reaction,the optimum concentration of substrate was 7%and the best reaction time was 36 h.On the condition of the test results,56.0 g PPD was added into the reactor for biotransformation,the reaction temperature was 45?.The weight of the crude product obtained from the enzyme reaction with desugared by macroporous adsorption resin AB-8,decolored by ion exchange resin D-280,concentrated and dried was 40.0 g,the yield was 71.4%.The 40.0 g crude product was isolated by silica gel column chromatography,elution solvent:V(chloroform):V(methanol):V(water)=9:1:0.03.The isolated ginsenosides:C-Mc,0.70 g,yield 1.80%;C-K,18.3 g,yield 45.7%;C-Y,1.26 g,yield 3.15%;F2,3.49 g,yield 8.72%;GypLXXV,0.14 g,yield 0.35%.The test result by HPLC:C-Mc,purity 68.23%;C-K,purity 95.27%;C-Y,purity 74.85%;F2,purity 99.87%.3.49 g F2 was transformed into Rh2 group by ginseng extract compound enzyme,the crude were mixture of 20(S)-Rh2 and 20(R)-Rh2 by silica gel chromatography,its weight 2.22 g,yield 63.6%.2.0 g mixture of 20(S)-Rh2 and 20(R)-Rh2 was crystallized for preparing 20(S)-Rh2,the weight of 20(S)-Rh2 was 0.16 g,purity 76.17%,yield 8%.The structure of product was determind as ginsenoside C-Mc by NMR.System name is 20-O-[a-L-arabinofuranosyl-(1?6)-?-D-glucopyranosyl]-20(S)-protopanaxadiol,molecular formula:C41H70O12.