Identification of novel glycoside hydrolases via whole genome sequencing of Niabella ginsenosidivorans for production of various minor ginsenosides

Biosynthesis of a Novel Ginsenoside with High Anticancer Activity by Recombinant UDP-Glycosyltransferase and Characterization of Its Biological Properties

UDP-glycosyltransferases (UGTs) contribute to catalyzing the glycosylation of numerous functional natural products and novel derivatives with improved bioactivities. UDP-glucose sterol glucosyltransferase (SGT) is normally involved in the synthesis of sterol glycosides in a variety of organisms. SGT was derived from Salinispora tropica CNB-440 and heterologously expressed in Escherichia coli BL21 (DE3). Novel 12-O-glucosylginsenoside Rh2 was identified using HPLC, high-resolution MS (HR-MS), and NMR analysis. The cell viability assay was performed on 12-O-glucosylginsenoside-treated AGS stomach cancer, HeLa cervical cancer, U87MG glioma, and B16F10 melanoma cell lines. Protein structure modeling, molecular docking, and dynamics simulations were performed using AutoDock 4.2 and GROMACS 2020.1 software. The SGT gene is comprised of 1284 nucleotides and codes for 427 amino acids. The 12-O-glucosylginsenoside Rh2 may be a potential anticancer agent due to its potent viability inhibition of cancer cells. Structural analysis showed critical perspectives into the intermolecular interactions, stability, and binding energetics of the enzyme-ligand complex, with outcomes complementing the experimental data, thereby deepening our understanding of the structural basis of SGT-mediated glycosylation and its functional implications. This report presents a novel ginsenoside, 12-O-glucosylginsenoside Rh2, utilizing reshuffled SGT derived from S. tropica, and provides a promising candidate for anticancer drug research and development.

Cloning, characterization of β-glucosidase from Furfurilactobacillus rossiae in bioconversion and its efficacy

Minor ginsenosides produced by β-glucosidase are interesting biologically and pharmacologically. In this study, new ginsenoside-hydrolyzing glycosidase from Furfurilactobacillus rossiae DCYL3 was cloned and expressed in Escherichia coli strain BL21. The enzyme converted Rb1 and Gyp XVII into Rd and compound K following the pathways: Rb1→Rd and Gyp XVII→F2→CK, respectively at optimal condition: 40 °C, 15 min, and pH 6.0. Furthermore, we examined the cytotoxicity, NO production, ROS generation, and gene expression of Gynostemma extract (GE) and bioconverted Gynostemma extract (BGE) in vitro against A549 cell lines for human lung cancer and macrophage RAW 264.7 cells for antiinflammation, respectively. As a result, BGE demonstrated significantly greater toxicity than GE against lung cancer at a dose of 500 µg/mL but in normal cells showed lower toxicity. Then, we indicated an enhanced generation of ROS, which may be boosting cancer cell toxicity. By blocking the intrinsic way, BGE increased p53, Bax, Caspase 3, 9, and while Bcl2 is decreased. At 500 µg/mL, the BGE sample was less toxic in normal cells and decreased the LPS-treated NO and ROS level to reduce inflammation. In addition, BGE inhibited the expression of pro-inflammatory genes COX-2, iNOS, IL-6, and IL-8 in RAW 264.7 cells than the sample of GE. In conclusion, FrBGL3 has considerable downstream applications for high-yield, low-cost, effective manufacture of minor ginsenosides. Moreover, the study's findings imply that BGE would be potential materials for anti-cancer and anti-inflammatory agent after consideration of future studies.

β-Glucosidase and Its Application in Bioconversion of Ginsenosides in Panax ginseng

Ginsenosides are a group of bioactive compounds isolated from Panax ginseng. Conventional major ginsenosides have a long history of use in traditional medicine for both illness prevention and therapy. Bioconversion processes have the potential to create new and valuable products in pharmaceutical and biological activities, making them both critical for research and highly economic to implement. This has led to an increase in the number of studies that use major ginsenosides as a precursor to generate minor ones using β-glucosidase. Minor ginsenosides may also have useful properties but are difficult to isolate from raw ginseng because of their scarcity. Bioconversion processes have the potential to create novel minor ginsenosides from the more abundant major ginsenoside precursors in a cost-effective manner. While numerous bioconversion techniques have been developed, an increasing number of studies have reported that β-glucosidase can effectively and specifically generate minor ginsenosides. This paper summarizes the probable bioconversion mechanisms of two protopanaxadiol (PPD) and protopanaxatriol (PPT) types. Other high-efficiency and high-value bioconversion processes using complete proteins isolated from bacterial biomass or recombinant enzymes are also discussed in this article. This paper also discusses the various conversion and analysis methods and their potential applications. Overall, this paper offers theoretical and technical foundations for future studies that will be both scientifically and economically significant.

Microorganisms for Ginsenosides Biosynthesis: Recent Progress, Challenges, and Perspectives

Ginsenosides are major bioactive compounds present in the Panax species. Ginsenosides exhibit various pharmaceutical properties, including anticancer, anti-inflammatory, antimetastatic, hypertension, and neurodegenerative disorder activities. Although several commercial products have been presented on the market, most of the current chemical processes have an unfriendly environment and a high cost of downstream processing. Compared to plant extraction, microbial production exhibits high efficiency, high selectivity, and saves time for the manufacturing of industrial products. To reach the full potential of the pharmaceutical resource of ginsenoside, a suitable microorganism has been developed as a novel approach. In this review, cell biological mechanisms in anticancer activities and the present state of research on the production of ginsenosides are summarized. Microbial hosts, including native endophytes and engineered microbes, have been used as novel and promising approaches. Furthermore, the present challenges and perspectives of using microbial hosts to produce ginsenosides have been discussed.

Phnomibacter ginsenosidimutans gen. nov., sp. nov., a novel glycoside hydrolase positive bacterial strain with ginsenoside hydrolysing activity

The conversion of major ginsenosides into minor ginsenosides attracts a lot of interest because of their biological and pharmaceutical activities. Therefore, for the conversion of ginsenosides, finding a novel competent glycoside hydrolase-producing bacterial strain is useful for future research studies and the mass production of minor ginsenosides. Wastewater samples were collected and screened for novel glycoside hydrolase bacterial strains using Reasoner's 2A+aesculin agar medium. As a result, a novel glycoside hydrolase positive bacterial strain (SB-02^T) was identified and subjected to a polyphasic taxonomic analysis. Based on genome analysis, strain SB-02^T was found to be affiliated with the family Chitinophagaceae and have less than 92.8 % sequence similarity to other members of the same family. Functional analysis indicated that SB-02^T was able to hydrolyse the ginsenosides Rb1, Rc and Rd to F2 and C-K. Due to the conversion of ginsenosides, the strain's genome was sequenced and the genes were annotated by the NCBI. The average amino acid identity and average nucleotide identity values between SB-02^T and the available reference genomes were 65.7 and 65.9 %, respectively. The novel isolate contained MK-7 as the predominant menaquinone, the major polyamine putrescine, and iso-C_15 : 0, iso-C_15 : 1 G and iso-C_17 : 0 3-OH as major fatty acids. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Thus, based on the data presented here, strain SB-02^T represents a novel species within a new genus in the family Chitinophagaceae, for which the name Phnomibacter ginsenosidimutans gen. nov., sp. nov. is proposed. The type strain of Phnomibacter ginsenosidimutans is SB-02^T (=KACC 21266^T=LMG 31707^T). The genome annotation of SB-02^T shows many glycoside hydrolase genes, which may be responsible for the efficient production of many kinds of minor ginsenosides and will be very helpful for future research (target gene cloning) and mass production of either F2 or C-K.

Enhanced production of ginsenoside Rh2(S) from PPD-type major ginsenosides using BglSk cloned from Saccharibacillus kuerlensis together with two glycosidase in series

Background

Ginsenoside Rh2(S) is a promising compound for the prevention of various kinds of cancers, inflammation, and diabetes. However, due to its low concentration (<0.02%), researchers are still trying to find an efficient glycoside hydrolase for the scaled-up production of Rh2(S).

Method

Three glycoside hydrolases (BglBX10, Abf22-3, and BglSk) were cloned in Escherichia coli BL21 (DE3) and the expressed recombinant enzyme was used for the scaled-up production of Rh2(S) through the conversion of PPD-type (protopanaxadiol) major ginsenosides (Rb1, Rc, and Rd, except Rb2) extracted from Korean red ginseng. Specific and specialized bioconversion pathways were designed that evolved the initial bioconversion of PPD-mix → Rg3(S) → Rh2(S). The reaction was started with 50 mg/mL of PPD-mix, 20 mg/mL of BglBX10, Abf22-3, and BglSk in series, respectively. The process was completed in a 10 L jar fermenter with a 5 L working volume at 37 °C for 48 hrs.

Results

The designed bioconversion pathways show that Abf22-3 and BglBX10 were responsible for the conversion of Rb1, Rc and Rd → Rg3(S), and then Rg3(S) was completely transformed to Rh2(S) by BglSk. As a result, 15.1 g of ginsenoside Rh2(S) with 98.0 ± 0.2% purity was obtained after strict purification using the Prep-HPLC system with a 100 φ diameter column. Additionally, BglSk was also investigated for its production activity with seven different kinds of PPD-mix type ginsenosides.

Conclusion

Our pilot data demonstrate that BglSk is a suitable enzyme for the gram unit production of ginsenoside Rh2(S) at the industrial level.