A novel ginsenoside-hydrolyzing enzyme from Penicillium oxalicum and its application in ginsenoside Rd production

Abstract

The fungus Penicillum oxalicum can selectively metabolize the major 20(S)-protopanaxadiol ginsenosides Rb1, Rb2, and Rc using extracellular glycosidases yielding a series of bioactive metabolites. A β-glucosidase GH1 was purified from the culture of P. oxalicum with a yield of 9.5% and a specific activity of 3.9 × 10³ U/mg. GH1 was a tetramer with a native molecular weight of 484 kDa and its pI value was pH 4.2. GH1 specifically cleaved the β-(1-6)-glucosidic linkage at C-20 site of ginsenoside Rb1 to give the sole product Rd. The optimum conditions were established to be pH 4.5, 55°C, and 0.25 U/ml purified enzyme at 2 mg/ml ginsenoside Rb1. GH1 could be used in the pharmaceutical industry.

Keywords::

• Ginsenoside Rb1
• ginsenoside Rd
• β-glucosidase
• Penicillium oxalicum
• biotransformation

Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.

This work was supported by the Chinese New Drug Creation and Manufacturing Program (2012ZX09502001-001) and the National Natural Science Foundation of China (31170770).