Purification and characterization of glycyrrhizin-β-d-glucuronidase and baicalin-β-d-glucuronidase from a commercial enzyme preparation

Abstract

Five commercial enzyme preparations were screened for hydrolysis of the glucuronic acid units of glycyrrhizin (GL) and baicalin. Two preparations hydrolyzing GL to glycyrrhetic acid (GA) and four enzyme preparations hydrolyzing baicalin to baicalein were obtained. One enzyme preparation with the ability to hydrolyze both GL and baicalin, namely Rapidase Pineapple, was purified by anion exchange, cation exchange and molecular sieve chromatography. The results of purification indicated that the enzymes containing the glycyrrhizin-β-d-glucuronidase (GBDG) and baicalin-β-d-glucuronidase (BBDG) activities were distinct, with different substrate specificities, molecular weights and enzymatic characteristics. GBDB hydrolyzed GL to GA, but had no detectable activity on baicalin, and BBDG hydrolyzed baicalin to baicalein, but could not hydrolyze GL. However, both GBDG and BBDG could hydrolyze the artificial substrate p-nitrophenyl- β-d-glucuronide (pNPGA).

Keywords::

• Purification
• biotransformation
• glycyrrhizin
• baicalin
• enzyme

Acknowledgements

The project was supported by the National Nature Science Foundation of China (NSFC; grant no. 20672142).

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