Specific Conversion of Ginseng Saponin by the Enzyme of Rhizopus japonicus

The enzyme produced by a strain of Rhizopus japonicus was able to covert selectively ginsenoside which was the most abundant ginseng saponin, into ginsenoside Rd which was known to be superior to ginsenoside pharmaceutically. This specific conversion of ginsenoside without any change of other ginsenoside patterns was confirmed by thin layer chromatography and high performance liquid chromatograpy quantitatively. The amount of ginsenoside Rd was increased to 4.8 and 34.7 folds by enzymatic conversion of ginsenoside in total saponin and ginsenoside Rb group saponin, respectively. The increased amount of ginsenoside Rd corresponded to total amount of released glucose and decreased amount of ginsenoside accurately.