A Versatile Enzyme Prefers Converting Ginsenoside Rb3 to Rd over Other Types

Greg Howard
26th July, 2024

A Versatile Enzyme Prefers Converting Ginsenoside Rb3 to Rd over Other Types

Image Source: Natural Science News, 2024

Key Findings

  • The study from Changchun University found a way to make ginsenosides from ginseng more absorbable using a specific enzyme
  • The enzyme, Pxbgl, converts complex ginsenosides into a more effective form called Rd, improving their absorption
  • The enzyme showed high efficiency, especially for converting Rb3, making it promising for industrial use in producing bioactive ginsenosides
Ginseng, a traditional medicinal herb, has been extensively studied for its health benefits, primarily attributed to its bioactive compounds known as ginsenosides. These compounds, however, often face absorption challenges due to their complex sugar chains, limiting their efficacy. Recent research from Changchun University has introduced a novel approach to enhance the bioavailability of ginsenosides by converting them into more absorbable forms using a specific enzyme[1]. Ginsenosides are categorized into different types based on their structural features, including protopanaxadiol (PPD) and protopanaxatriol (PPT) types, among others[2]. The study from Changchun University focuses on PPD-type ginsenosides, specifically Rb1, Rb2, Rb3, and Rc, which are converted into a more efficacious form, Rd, using a β-glycosidase enzyme (Pxbgl) derived from the xylan-degrading bacterium Petroclostridium xylanilyticum. In the context of ginseng's pharmacological activities, deglycosylated ginsenosides like Rd are more potent than their glycosylated counterparts. This is because the removal of sugar moieties enhances their absorption through the intestinal membrane[3][4]. The study highlights that Pxbgl exhibits a significantly higher catalytic efficiency (kcat/Km value) for Rb3 compared to other ginsenosides, making it a particularly effective enzyme for this conversion. The productivity of Rd using Pxbgl was notably high, achieving 5884 μM/h, which is 346 times greater than the productivity achieved using only β-xylosidase from Thermoascus aurantiacus. This remarkable efficiency underscores the potential of Pxbgl in industrial applications for producing bioactive ginsenosides. Additionally, the study reports that the productivity of Rd from Panax ginseng root and Panax notoginseng leaf was 146 and 995 μM/h, respectively, further demonstrating the enzyme's versatility. The researchers also employed site-directed mutagenesis, a technique used to introduce specific mutations into the enzyme to enhance its activity. Two mutants, N293 K and I447L, showed an increase in specific activity towards Rb3 by 29% and 7%, respectively. This indicates the potential for further optimization of Pxbgl to enhance its catalytic efficiency. Previous studies have explored various methods for preparing rare ginsenosides like Rg3 and Rh2, which have shown significant pharmacological effects, including anti-inflammatory, anticancer, and neuroprotective properties[3][4]. However, the conversion rates and production costs remain bottlenecks in industrial-scale production. The current study addresses these challenges by demonstrating a highly efficient enzymatic conversion process, potentially lowering production costs and increasing yield. Moreover, the study expands on the understanding of ginsenoside biosynthesis and the role of specific enzymes in this process. Ginsenosidases, the enzymes responsible for hydrolyzing glycosylated ginsenosides, have been classified based on their activity on different sugar moieties and positions[4]. The identification of Pxbgl as a β-glycosidase capable of removing four different glycosyls at the C-20 position of PPD-type ginsenosides adds a valuable tool to the arsenal of biotechnological applications for ginsenoside production. In conclusion, the research from Changchun University presents a significant advancement in the field of ginsenoside biotransformation. By utilizing the β-glycosidase Pxbgl, the study offers a highly efficient method for converting complex ginsenosides into more bioavailable forms, potentially enhancing their therapeutic efficacy and facilitating their industrial production. This work not only builds on previous findings but also opens new avenues for optimizing and scaling up the production of valuable ginsenosides.

MedicineBiotechBiochem

References

Main Study

1) A Versatile β-Glycosidase from Petroclostridium xylanilyticum Prefers the Conversion of Ginsenoside Rb3 over Rb1, Rb2, and Rc to Rd by Its Specific Cleavage Activity toward 1,6-Glycosidic Linkages.

Published 25th July, 2024

https://doi.org/10.1021/acs.jafc.4c03909

Related Studies

2) Saponins in the genus Panax L. (Araliaceae): a systematic review of their chemical diversity.

https://doi.org/10.1016/j.phytochem.2014.07.012

3) Preparation and bioactivity of the rare ginsenosides Rg3 and Rh2: An updated review.

https://doi.org/10.1016/j.fitote.2023.105514

4) Classification of glycosidases that hydrolyze the specific positions and types of sugar moieties in ginsenosides.

Journal: Critical reviews in biotechnology, Issue: Vol 36, Issue 6, Dec 2016


Related Articles

An unhandled error has occurred. Reload 🗙