Microbial conversion of rare ginsenoside Rf to 20(S)-protopanaxatriol by Aspergillus niger.

Lei Liu, Li-Juan Gu, Dong-Liang Zhang, Zhen Wang, Chun-Yan Wang, Zheng Li, Chang-Keun Sung

Index: Biosci. Biotechnol. Biochem. 74(1) , 96-100, (2010)

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Abstract

In this study, rare ginsenoside Rf was transformed into 20(S)-protopanaxatriol (PPT(S)) by glycosidase from Aspergillus niger. By investing the reaction conditions, the optimal conditions were obtained, as follows: pH 5.0, temperature 55 degrees C, and substrate concentration 1.25 mmol/l. Under optimal conditions, PPT(S) (1.13 micromol) prepared from 1.25 mumol Rf showed a higher yield (90.4%). The enzymatic reaction was analyzed by reversed-phase HPLC, suggesting the transformation pathway: Rf-->Rh1(S)-->PPT(S).