Preparation of minor ginsenosides from Panax notoginseng root and flower by the extracted enzyme of Mucor abundans

Abstract

Minor ginsenosides, known for their superior biological activities in comparison to major ginsenosides, are relatively scarce in nature. Therefore, this study explored the utility of Mucor abundans enzyme in transformating major ginsenosides obtained from the root and flower of Panax notoginseng into minor ginsenosides. Comprehensive analysis and verification of the conversion products (minor ginsenosides) were conducted employing an array of techniques, including TLC, HPLC, and MS. Additionally, the study proposed conversion pathways for the major ginsenosides by dynamically monitoring the changes of substrates and products during the conversion process. The study found that the M. abundans enzyme can successfully converted ginsenosides Rb1, Rb2, Rb3, Rc, Re, Rg1, and notoginsenoside R1 from P. notoginseng into 22 minor ginsenosides via processes such as deglycosylation, epimerization and dehydration, with conversion rates varying from 37.0% to 98.9%. The enzyme, purified and presenting a molecular weight of approximately 69 kDa, primarily catalyzed the hydrolysis of glycoside bonds at positions C-3 and C-20 of PPD-type ginsenosides, and C-20 position of PPT-type ginsenosides, thus facilitating the conversion of major to minor ginsenosides. This exploration potentates the enhanced functionality and proportionately increased economic value of P. notoginseng.