Enzymatic transformation of ginseng leaf saponin by recombinant β-glucosidase (bgp1) and its efficacy in an adipocyte cell line

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.

Advances and challenges in ginseng research from 2011 to 2020: the phytochemistry, quality control, metabolism, and biosynthesis

Covering: 2011 to the end of 2020Panax species (Araliaceae), particularly P. ginseng, P. quinquefolius, and P. notoginseng, have a long history of medicinal use because of their remarkable tonifying effects, and currently serve as crucial sources for various healthcare products, functional foods, and cosmetics, aside from their vast clinical preparations. The huge market demand on a global scale prompts the continuous prosperity in ginseng research concerning the discovery of new compounds, precise quality control, ADME (absorption/disposition/metabolism/excretion), and biosynthesis pathways. Benefitting from the ongoing rapid development of analytical technologies, e.g. multi-dimensional chromatography (MDC), personalized mass spectrometry (MS) scan strategies, and multi-omics, highly recognized progress has been made in driving ginseng analysis towards "systematicness, integrity, personalization, and intelligentization". Herein, we review the advances in the phytochemistry, quality control, metabolism, and biosynthesis pathway of ginseng over the past decade (2011-2020), with 410 citations. Emphasis is placed on the introduction of new compounds isolated (saponins and polysaccharides), and the emerging novel analytical technologies and analytical strategies that favor ginseng's authentic use and global consumption. Perspectives on the challenges and future trends in ginseng analysis are also presented.

Whitening and inhibiting NF-κB-mediated inflammation properties of the biotransformed green ginseng berry of new cultivar K1, ginsenoside Rg2 enriched, on B16 and LPS-stimulated RAW 264.7 cells

Background

Main bioactive constituents and pharmacological functions of ripened red ginseng berry (Panax ginseng Meyer) have been frequently reported. Yet, the research gap targeting the beneficial activities of transformed green ginseng berries has not reported elsewhere.

Methods

Ginsenosides of new green berry cultivar K-1 (GK-1) were identified by HPLC-QTOF/MS. Ginsenosides bioconversion in GK-1 by bgp1 enzyme was confirmed with HPLC and TLC. Then, mechanisms of GK-1 and β-glucosidase (bgp1) biotransformed GK-1 (BGK-1) were determined by Quantitative Reverse Transcription-Polymerase Chain Reaction and Western blot.

Results

GK-1 possesses highest ginsenosides especially ginsenoside-Re amongst seven ginseng cultivars including (Chunpoong, Huangsuk, Kumpoong, K-1, Honkaejong, Gopoong, and Yunpoong). Ginseng root’s biomass is not affected with the harvest of GK-1 at 3 weeks after flowering period. Then, Re is bio-converted into a promising pharmaceutical effect of Rg2 via bgp1. According to the results of cell assays, BGK-1 shows decrease of tyrosinase and melanin content in α-melanocyte-stimulating hormone challenged-murine melanoma B16 cells. BGK-1 which is comparatively more effective than GK-1 extract shows significant suppression of the nuclear factor (NF)-κB activation and inflammatory target genes, in LPS-stimulated RAW 264.7 cells.

Conclusion

These results reported effective whitening and anti-inflammatory of BGK-1 as compared to GK-1.

Chitinophaga chungangae sp. nov., isolated from a Korean grape garden and its potential to biosynthesize ginsenoside Rg2

A ginsenoside Rg2-producing, Gram stain-negative, aerobic, catalase and oxidase-positive, rod-shaped, non-motile and orange pigmented novel bacterium designated strain MAH-28 ^T was isolated from soil sample of a grape garden. Strain MAH-28 ^T hydrolyzed aesculin, casein and DNA. Flexirubin-type pigments are present. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain MAH-28 ^T formed a cluster within the genus Chitinophaga and the most close relatives were Chitinophaga alhagiae T22^T (98.9% 16S rRNA gene sequence similarity), Chitinophaga humicola Ktm-2 ^T (98.8%), Chitinophaga barathri YLT18^T (98.3%) and Chitinophaga lutea ZY74^T (97.4%). The novel strain MAH-28 ^T has a draft genome size of 6,043,180 bp (14 contigs), annotated with 4,863 protein-coding genes, 53 tRNA and 6 rRNA genes. The ANI and dDDH values between strain MAH-28 ^T and the closely related type strains were in the range of 76.0-83.4% and 20.3-26.7%, respectively. The novel strain MAH-28 ^T was able to synthesize ginsenoside Rg2 from major ginsenoside Re. The genome annotation revealed 152 carbohydrate genes which may involve with the synthesis of ginsenoside Rg2. The respiratory quinone of strain MAH-28 ^T was MK-7 and the dominant cellular fatty acids were C_{15:0 iso}, C_16:1 ω5c and C_{17:0 iso} 3-OH. The DNA G + C content of strain MAH-28 ^T was 53.3 mol%. Based on the phenotypic, chemotaxonomic and phylogenetic studies, strain MAH-28 ^T represents a new member of genus Chitinophaga for which the name Chitinophaga chungangae sp. nov. is proposed with type strain MAH-28 ^T (= KACC 19968 ^T = CGMCC 1.16605 ^T).

Paenibacillus roseus sp. nov., a ginsenoside-transforming bacterium isolated from forest soil

A novel, pink-pigmented, Gram-stain-positive, aerobic, motile, rod-shaped and ginsenoside-converting bacterium, designated strain MAHUQ-46^T, was isolated from soil of a forest. Strain MAHUQ-46^T grew in the pH range 6.0-9.0 (optimum, 7.5), at temperatures between 10 and 37 °C (optimum, 30 °C) and at 0-3% (w/v) NaCl (optimum, 0.5%). 16S rRNA gene sequence analysis showed that strain MAHUQ-46^T was closely related to Paenibacillus pinihumi S23^T (97.3% similarity), followed by Paenibacillus elymi KUDC6143^T (96.7%). The draft genome of strain MAHUQ-46^T had a total length of 5,367,904 base pairs. A total of 4,857 genes were identified, in which 4,629 were protein-coding genes and 137 were RNA genes. The genome annotation of MAHUQ-46^T showed 172 carbohydrate genes, some of them may be responsible for the biosynthesis of ginsenoside Rd from major ginsenoside Rb1. The DNA G + C content was 48.4 mol% and the major quinone was MK-7. Main fatty acids of strain MAHUQ-46^T were C_{15: 0 anteiso}, C_16: 0 and C_{17: 0 anteiso}. The polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidyl-N-methylethanolamine, two unidentified aminophospholipids and five unidentified phospholipids. Diagnostic diamino acid of peptidoglycan was meso-diaminopimelic acid. The novel strain MAHUQ-46^T was able to rapidly synthesize ginsenoside Rd from major ginsenoside Rb1. The synthesized ginsenoside was confirmed by TLC and HPLC analysis. According to the phenotypic, genetic and chemotaxonomic evidence, strain MAHUQ-46^T was clearly distinguishable from validly published species of genus Paenibacillus and should, therefore, be categorized as a novel species for which the name Paenibacillus roseus sp. nov. is proposed. The type strain is MAHUQ-46^T (= KACC 21242^T = CGMCC 1.17353^T).

Spectroscopic and in silico investigation of the interaction between GH1 β-glucosidase and ginsenoside Rb1

The function and application of β-glucosidase attract attention nowadays. β-glucosidase was confirmed of transforming ginsenoside Rb1 to rare ginsenoside, but the interaction mechanism remains not clear. In this work, β-glucosidase from GH1 family of Paenibacillus polymyxa was selected, and its gene sequence bglB was synthesized by codon. Then, recombinant plasmid was transferred into Escherichia coli BL21 (DE3) and expressed. The UV-visible spectrum showed that ginsenoside Rb1 decreased the polarity of the corresponding structure of hydrophobic aromatic amino acids (Trp) in β-glucosidase and increased new π-π* transition. The fluorescence quenching spectrum showed that ginsenoside Rb1 inhibited intrinsic fluorescence, formed static quenching, reduced the surface hydrophobicity of β-glucosidase, and KSV was 8.37 × 103 L/M (298K). Circular dichroism (CD) showed that secondary structure of β-glucosidase was changed by the binding action. Localized surface plasmon resonance (LSPR) showed that β-glucosidase and Rb1 had strong binding power which KD value was 5.24 × 10-4 (±2.35 × 10-5) M. Molecular docking simulation evaluated the binding site, hydrophobic force, hydrogen bond, and key amino acids of β-glucosidase with ginsenoside Rb1 in the process. Thus, this work could provide basic mechanisms of the binding and interaction between β-glucosidase and ginsenoside Rb1.

Diversity of Ginsenoside Profiles Produced by Various Processing Technologies

Ginseng is a traditional medicinal herb commonly consumed world-wide owing to its unique family of saponins called ginsenosides. The absorption and bioavailability of ginsenosides mainly depend on an individual's gastrointestinal bioconversion abilities. There is a need to improve ginseng processing to predictably increase the pharmacologically active of ginsenosides. Various types of ginseng, such as fresh, white, steamed, acid-processed, and fermented ginsengs, are available. The various ginseng processing methods produce a range ginsenoside compositions with diverse pharmacological properties. This review is intended to summarize the properties of the ginsenosides found in different Panax species as well as the different processing methods. The sugar moiety attached to the C-3, C-6, or C-20 deglycosylated to produce minor ginsenosides, such as Rb1, Rb2, Rc, Rd→Rg3, F2, Rh2; Re, Rf→Rg1, Rg2, F1, Rh1. The malonyl-Rb1, Rb2, Rc, and Rd were demalonylated into ginsenoside Rb1, Rb2, Rc, and Rd by dehydration. Dehydration also produces minor ginsenosides such as Rg3→Rk1, Rg5, Rz1; Rh2→Rk2, Rh3; Rh1→Rh4, Rk3; Rg2→Rg6, F4; Rs3→Rs4, Rs5; Rf→Rg9, Rg10. Acetylation of several ginsenosides may generate acetylated ginsenosides Rg5, Rk1, Rh4, Rk3, Rs4, Rs5, Rs6, and Rs7. Acid processing methods produces Rh1→Rk3, Rh4; Rh2→Rk1, Rg5; Rg3→Rk2, Rh3; Re, Rf, Rg2→F1, Rh1, Rf2, Rf3, Rg6, F4, Rg9. Alkaline produces Rh16, Rh3, Rh1, F4, Rk1, ginsenoslaloside-I, 20(S)-ginsenoside-Rh1-60-acetate, 20(R)-ginsenoside Rh19, zingibroside-R1 through hydrolysis, hydration addition reactions, and dehydration. Moreover, biological processing of ginseng generates the minor ginsenosides of Rg3, F2, Rh2, CK, Rh1, Mc, compound O, compound Y through hydrolysis reactions, and synthetic ginsenosides Rd12 and Ia are produced through glycosylation. This review with respect to the properties of particular ginsenosides could serve to increase the utilization of ginseng in agricultural products, food, dietary supplements, health supplements, and medicines, and may also spur future development of novel highly functional ginseng products through a combination of various processing methods.

Integrated analysis on biochemical profiling and transcriptome revealed nitrogen-driven difference in accumulation of saponins in a medicinal plant Panax notoginseng

The medicinal plant Panax notoginseng is considered a promising source of secondary metabolites due to its saponins. However, there are relatively few studies on the response of saponins to nitrogen (N) availability and the mechanisms underlying the N-driven regulation of saponins. Saponins content and saponins -related genes were analyzed in roots of P. notoginseng grown under low N (LN), moderate N (MN) and high N (HN). Saponins was obviously increased in LN individuals with a reduction in β-glucosidase activity. LN facilitated root architecture and N uptake rate. Compared with the LN individuals, 2872 and 1122 genes were incorporated into as differently expressed genes (DEGs) in the MN and HN individuals. Clustering and enrichment showed that DEGs related to "carbohydrate biosynthesis", "plant hormone signal transduction", "terpenoid backbone biosynthesis", "sesquiterpenoid and triterpenoid biosynthesis" were enriched. The up-regulation of some saponins-related genes and microelement transporters was found in LN plants. Whereas the expression of IPT3, AHK4 and GS2 in LN plants fell far short of that in HN ones. Anyways, LN-induced accumulation of C-based metabolites as saponins might derive from the interaction between N and phytohormones in processing of N acquisition, and HN-induced reduction of saponins might be result from an increase in the form of β-glucosidase activity and N-dependent cytokinins (CKs) biosynthesis.

Stem-leaves of Panax as a rich and sustainable source of less-polar ginsenosides: comparison of ginsenosides from Panax ginseng, American ginseng and Panax notoginseng prepared by heating and acid treatment

Background

Ginsenosides, which have strong biological activities, can be divided into polar or less-polar ginsenosides.

Methods

This study evaluated the phytochemical diversity of the saponins in Panax ginseng (PG) root, American ginseng (AG) root, and Panax notoginseng (NG) root; the stem-leaves from Panax ginseng (SPG) root, American ginseng (SAG) root, and Panax notoginseng (SNG) root as well as the saponins obtained following heating and acidification [transformed Panax ginseng (TPG), transformed American ginseng (TAG), transformed Panax notoginseng (TNG), transformed stem-leaves from Panax ginseng (TSPG), transformed stem-leaves from American ginseng (TSAG), and transformed stem-leaves from Panax notoginseng (TSNG)]. The diversity was determined through the simultaneous quantification of the 16 major ginsenosides.

Results

The content of ginsenosides in NG was found to be higher than those in AG and PG, and the content in SPG was greater than those in SNG and SAG. After transformation, the contents of polar ginsenosides in the raw saponins decreased, and contents of less-polar compounds increased. TNG had the highest levels of ginsenosides, which is consistent with the transformation of ginseng root. The contents of saponins in the stem-leaves were higher than those in the roots. The transformation rate of SNG was higher than those of the other samples, and the loss ratios of total ginsenosides from NG (6%) and SNG (4%) were the lowest among the tested materials. In addition to the conversion temperature, time, and pH, the crude protein content also affects the conversion to rare saponins. The proteins in Panax notoginseng allowed the highest conversion rate.

Conclusion

Thus, the industrial preparation of less-polar ginsenosides from SNG is more efficient and cheaper.