Isoginsenoside-Rh3, a new triterpenoid saponin from the fruits of Panax ginseng C. A. Mey

Rare ginsenosides: A unique perspective of ginseng research

BACKGROUND

Rare ginsenosides (Rg3, Rh2, C-K, etc.) refer to a group of dammarane triterpenoids that exist in low natural abundance, mostly produced by deglycosylation or side chain modification via physicochemical processing or metabolic transformation in gut, and last but not least, exhibited potent biological activity comparing to the primary ginsenosides, which lead to a high concern in both the research and development of ginseng and ginsenoside-related nutraceutical and natural products. Nevertheless, a comprehensive review on these promising compounds is not available yet.

AIM OF REVIEW

In this review, recent advances of Rare ginsenosides (RGs) were summarized dealing with the structurally diverse characteristics, traditional usage, drug discovery situation, clinical application, pharmacological effects and the underlying mechanisms, structure-activity relationship, toxicity, the stereochemistry properties, and production strategies.

KEY SCIENTIFIC CONCEPTS OF REVIEW

A total of 144 RGs with diverse skeletons and bioactivities were isolated from Panax species. RGs acted as natural ligands on some specific receptors, such as bile acid receptors, steroid hormone receptors, and adenosine diphosphate (ADP) receptors. The RGs showed promising bioactivities including immunoregulatory and adaptogen-like effect, anti-aging effect, anti-tumor effect, as well as their effects on cardiovascular and cerebrovascular system, central nervous system, obesity and diabetes, and interaction with gut microbiota. Clinical trials indicated the potential of RGs, while high quality data remains inadequate, and no obvious side effects was found. The stereochemistry properties induced by deglycosylation at C (20) were also addressed including pharmacodynamics behaviors, together with the state-of-art analytical strategies for the identification of saponin stereoisomers. Finally, the batch preparation of targeted RGs by designated strategies including heating or acid/ alkaline-assisted processes, and enzymatic biotransformation and biosynthesis were discussed. Hopefully, the present review can provide more clues for the extensive understanding and future in-depth research and development of RGs, originated from the worldwide well recognized ginseng plants.

Inhibitory effects of polysaccharides from Korean ginseng berries on LPS-induced RAW264.7 macrophages

Polysaccharides isolated from Korean ginseng berries (GBPs) have shown beneficial effects such as immunomodulatory, anti-inflammatory, anti-cancer, and anti-diabetic properties. However, little is known about anti-inflammatory effects of GBPs. Thus, the purpose of this study was to investigate anti-inflammatory properties of four fractions of GBPs, namely GBP-C, GBP-F1, GBP-F2, and GBP-F3, in macrophages. Their toxicities and effects on NO production in RAW264.7 cells were assessed by culturing cells with various concentrations of GBPs and stimulating cells with LPS. Furthermore, expression levels of inflammatory mediators, cytokines, cell surface molecules, and immune signaling pathways were evaluated in LPS-stimulated macrophages using different fractions of GBPs at 450 μg/mL. These GBPs activated LPS-stimulated RAW264.7 cells to significantly reduce NO production. They suppressed the expression of mRNA and cell surface molecules via MAPK and NF-κB pathways. Collectively, results revealed that all four GBP fractions showed anti-inflammatory effects, with GBP-F1 having a more efficient anti-inflammatory effect than GBP-C, GBP-F2, and GBP-F3. The structure of GBP-F1 mainly consists of 1 → 3)- Araf, 1 → 4)- Glcp, and 1 → 6)-Galp glycosidic linkages. These results demonstrate that GBPs can be employed as alternative natural sources of anti-inflammatory agents.

Comprehensive investigation on metabolites of Panax quinquefolium L. in two main producing areas of China based on ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry

Jilin Province and Shandong Province are two main American ginseng (AG) producing areas in China. The geographical difference existed in these two provinces. Aiming at evaluating the similarities and differences of the secondary metabolites, the comprehensive metabolite profiling of AG from Jilin Province (AGJ ) and Shandong Province (AGS ) was performed based on UPLC-QTOF-MS for the first time. In screening analysis, a total of 111 shared compounds, with ginsenosides being major components, were identified or tentatively characterized, which indicated that AGJ and AGS were all rich in phytochemicals and contained similar structural types. Untargeted metabolomics analysis indicated that there were significant differences in the contents of certain constituents in AGJ and AGS . Nineteen (12 for AGJ , 7 for AGS ) potential producing area-dependent chemical markers were discovered. Based on the contents and MS responses, ginsenoside Rg1 , Re, and pseudoginsenoside F11 could be considered as the characteristical markers of AGJ , whereas ginsenoside Rg3 and Rh2 of AGS . This comprehensive phytochemical profile study could provide valuable chemical evidence for evaluating the characteristics qualities of AG from various producing areas.

Advances in Saponin Diversity of Panax ginseng

Ginsenosides are the major bioactive constituents of Panax ginseng, which have pharmacological effects. Although there are several reviews in regards to ginsenosides, new ginsenosides have been detected continually in recent years. This review updates the ginsenoside list from P. ginseng to 170 by the end of 2019, and aims to highlight the diversity of ginsenosides in multiple dimensions, including chemical structure, tissue spatial distribution, time, and isomeride. Protopanaxadiol, protopanaxatriol and C17 side-chain varied (C17SCV) manners are the major types of ginsenosides, and the constitute of ginsenosides varied significantly among different parts. Only 16 ginsenosides commonly exist in all parts of a ginseng plant. Protopanaxadiol-type ginsenoside is dominant in root, rhizome, leaf, stem, and fruit, whereas malonyl- and C17SCV-type ginsenosides occupy a greater proportion in the flower and flower bud compared with other parts. In respects of isomeride, there are 69 molecular formulas corresponding to 170 ginsenosides, and the median of isomers is 2. This is the first review on diversity of ginsenosides, providing information for reasonable utilization of whole ginseng plant, and the perspective on studying the physiological functions of ginsenoside for the ginseng plant itself is also proposed.

Different absorption and metabolism of ginsenosides after the administration of total ginsenosides and decoction of Panax ginseng

RATIONALE

Panax ginseng C.A. Meyer (PG), which contains polysaccharides and ginsenosides as the major bioactive components, has been used to promote health and treat diseases for thousands of years in China. Total ginsenosides were extracted from a decoction of Panax ginseng (GD), which included both ginsenosides and polysaccharides, and dissolved in water to obtain a total ginsenosides aqueous solution (TGAS). To study their absorption and metabolism, the pharmacokinetics (PK) and metabolites of ginsenosides in vivo were investigated after the administration of GD and TGAS.

METHODS

Rat and mice plasma samples were collected after the administration of GD and TGAS. Ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry was used with the UNIFI platform to identify metabolites in the plasma sample. The pharmacokinetic parameters were calculated using a noncompartmental method in the Drug and Statistics software package.

RESULTS

Thirty ginsenoside metabolites were identified in mice plasma, of which only seven were found in the rat plasma after the administration of GD. The PK of ginsenosides Rb₁ , Rc, and Rd were also determined after the oral administration of GD and TGAS and showed significant differences in the pharmacokinetic parameters.

CONCLUSIONS

There was no difference in the biotransformation pathways after the oral administration of GD and TGAS, indicating that there was no influence of polysaccharides on the biotransformation of ginsenosides in vivo. However, the pharmacokinetic parameters were different after the administration of GD and TGAS, possibly because of the polysaccharides in GD. This study should be of significance in exploring the basis of PG bioactivities and lays the foundation for the further development of new drugs using PG.

Screening ginseng saponins in progenitor cells identifies 20(R)-ginsenoside Rh2 as an enhancer of skeletal and cardiac muscle regeneration

Aging is associated with increased prevalence of skeletal and cardiac muscle disorders, such as sarcopenia and cardiac infarction. In this study, we constructed a compendium of purified ginsenoside compounds from Panax ginseng C.A. Meyer, which is a traditional Korean medicinal plant used to treat for muscle weakness. Skeletal muscle progenitor cell-based screening identified three compounds that enhance cell viability, of which 20(R)-ginsenoside Rh2 showed the most robust response. 20(R)-ginsenoside Rh2 increased viability in myoblasts and cardiomyocytes, but not fibroblasts or disease-related cells. The cellular mechanism was identified as downregulation of cyclin-dependent kinase inhibitor 1B (p27Kip1) via upregulation of Akt1/PKB phosphorylation at serine 473, with the orientation of the 20 carbon epimer being crucially important for biological activity. In zebrafish and mammalian models, 20(R)-ginsenoside Rh2 enhanced muscle cell proliferation and accelerated recovery from degeneration. Thus, we have identified 20(R)-ginsenoside Rh2 as a p27Kip1 inhibitor that may be developed as a natural therapeutic for muscle degeneration.

Molecular Interactions of Renin with Chikusetsusaponin IV and Momordin IIc

The paper dealt with the molecular mechanism for the binding sites and driving forces of renin with chikusetsusaponin IV and momordin IIc by means of molecular docking and free energy calculation based on the crystal structure. The result showed that renin and the saponins fit well. As shown by LigPlot + software analyzing the hydrogen bonding and hydrophobic effect between renin and the saponins, the amino acid residues such as Ser230, Tyr85, and Tyr201 form the hydrogen bonds, with S3sp, S3, and S2′ being the active pockets. In addition, there are relatively strong hydrophobic interactions of renin with saponins in S3sp, S3, S2, S1, S1′, and S2′, with Gly228, Val36, Ala229, Gln19, Met303, Gln135, Ser41, Ile137, Asp38, Arg82, and Tyr83 being the key amino acids. The dynamics reached equilibration after about 1000 ps simulation with average root-mean-square deviations of 0.222 nm and 0.217 nm. The molecular mechanics Poisson–Boltzmann surface area (MM-PBSA) yielded −1.10812 kcal/mol and −39.0587 kcal/mol total binding energy for the two complexes, respectively, which were primarily contributed by electrostatic and van der Waals interaction energies, and the binding was strongly unfavored by polar solvation energy, a further confirmation that momordin IIc has stronger hydrogen bonding and hydrophobic effect in the inhibition of renin than the chikusetsusaponin IV.

Anti-Cancer Effects of Panax ginseng Berry Polysaccharides via Activation of Immune-Related Cells

Panax ginseng has long been used as natural medicine and health food all over the world. Cancer is a major cause of death worldwide and its prognosis likely depends on the immune system during tumor treatment. In this study, ginseng berry polysaccharides were evaluated for their immunostimulant and anti-cancer effects. Ginseng berry polysaccharide portion (GBPP) was used to investigate its effects on anti-complementary activity, peritoneal macrophage activation, and natural killer (NK) cell cytotoxicity. Moreover, both intravenous (i.v.) and oral administration of GBPP prior to B16-BL6 melanoma implantation in mice was evaluated. GBPP significantly increased the anti-complementary activity and cytokine production including interleukin (IL)-6, IL-12, and tumor necrosis factor (TNF)-α, dose-dependently. Splenocytes obtained after i.v. administration of GBPP showed cytolytic activity in Yac-1 cells in proportion to the E/T ratio. In addition, GBPP enhanced the production of interferon (IFN)-γ and granzyme B of NK cells. For the experimental lung cancer, compared with control mice, GBPP delivered by i.v. suppressed cancer by 48% at 100 μg/mouse, while a 37% reduction was achieved by oral administration. Deficient of NK cells in animal model demonstrated that the anti-cancer effect of GBPP was through NK cell activation. Results of this study suggest that ginseng berry polysaccharides, owing to their modulation of the immune response, can be a potential curative applicant for the prevention and treatment of tumors.

Comprehensive Investigation on Metabolites of Wild-Simulated American Ginseng Root Based on Ultra-High-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry

Aiming to evaluate the similarities and differences of the phytochemicals in different morphological regions of wild-simulated American ginseng (WsAG) root, the comprehensive metabolite profiling of main root (MR), branch root (BR), rhizome (RH), adventitious root (AR), and fibrous root (FR) was performed on the basis of ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry for the first time. First, in the screening analysis, a total of 128 shared compounds were identified or tentatively characterized. The results showed that these five parts were all rich in phytochemicals and contained similar structure types. Second, in the untargeted metabolomic study, it was found that there indeed existed differences between the MR&BR group, RH&AR group, and FR part when considering the contents of every ingredient. A total of 31 (12, 7, and 12 for MR&BR, RH&AR, and FR, respectively) potential chemical markers enabling the differentiation were discovered. This comprehensive phytochemical profile study revealed the structural diversity of secondary metabolites and the similar/different patterns in five morphological regions of WsAG root. It could provide chemical evidence for the rational application of different parts of WsAG root.

Non-Targeted Metabolomic Analysis of Methanolic Extracts of Wild-Simulated and Field-Grown American Ginseng

Aiming at revealing the structural diversity of secondary metabolites and the different patterns in wild-simulated American ginseng (WsAG) and field-grown American ginseng (FgAG), a comprehensive and unique phytochemical profile study was carried out. In the screening analysis, a total of 121 shared compounds were characterized in FgAG and WsAG, respectively. The results showed that both of these two kinds of American ginseng were rich in natural components, and were similar in terms of the kinds of compound they contained. Furthermore, in non-targeted metabolomic analysis, when taking the contents of the constituents into account, it was found that there indeed existed quite a difference between FgAG and WsAG, and 22 robust known biomarkers enabling the differentiation were discovered. For WsAG, there were 12 potential biomarkers including two ocotillol-type saponins, two steroids, six damarane-type saponins, one oleanane-type saponins and one other compound. On the other hand, for FgAG, there were 10 potential biomarkers including two organic acids, six damarane-type saponins, one oleanane-type saponin, and one ursane. In a word, this study illustrated the similarities and differences between FgAG and WsAG, and provides a basis for explaining the effect of different growth environments on secondary metabolites.

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

The Panax genus is a crucial source of natural medicines that has benefited human health for a long time. Three valuable medicinal herbs, namely Panax ginseng, Panax quinquefolius, and Panax notoginseng, have received considerable interest due to their extensive application in clinical therapy, healthcare products, and as foods and food additives world-wide. Panax species are known to contain abundant levels of saponins, also dubbed ginsenosides, which refer to a series of dammarane or oleanane type triterpenoid glycosides. These saponins exhibit modulatory effects to the central nervous system and beneficial effects to patients suffering from cardiovascular diseases, and also have anti-diabetic and anti-tumor properties. To the end of 2012, at least 289 saponins were reported from eleven different Panax species. This comprehensive review describes the advances in the phytochemistry of the genus Panax for the period 1963-2012, based on the 134 cited references. The reported saponins can be classified into protopanaxadiol, protopanaxatriol, octillol, oleanolic acid, C17 side-chain varied, and miscellaneous subtypes, according to structural differences in sapogenins. The investigational history of Panax is also reviewed, with special attention being paid to the structural features of the six different subtypes, together with their (1)H and (13)C NMR spectroscopic characteristics which are useful for determining their structures and absolute configuration.

New dammarane-type triterpenoids from the leaves of Panax notoginseng and their protein tyrosine phosphatase 1B inhibitory activity

Background

Panax notoginseng has been used as a general tonic agent to invigorate human body for millennia in China and continued to be used until present.

Methods

Some chromatographic methods were performed to isolate pure triterpenoids, and their structures were determined by nuclear magnetic resonance (NMR) experiments. Anti-diabetes activities of isolated compounds were evaluated through their inhibitory activity of protein tyrosine phosphatase 1B (PTP1B) enzyme.

Results and Conclusion

Three new dammarane-type triterpenoids, notoginsenoside-LX (1), notoginsenoside-LY (2), and notoginsenoside-FZ (3) together with eighteen known compounds were isolated from the Panax notoginseng leaves. The structure-activity relationship of the compounds with dammarane-type triterpenoids and their PTP1B inhibitory activity were also reported. Results showed that compounds 2, 15, 20, and 21 can significantly inhibit the enzyme activity of PTP1B in a dose-dependent manner, with inhibitory concentration 50 (IC₅₀) values of 29.08 μM, 21.27 μM, 28.12 μM, and 26.59 μM, respectively. The results suggested that Panax notoginseng leaves might have potential as a new therapeutic agent for the treatment of diabetes.

Ginsenjilinol, a new protopanaxatriol-type saponin with inhibitory activity on LPS-activated NO production in macrophage RAW 264.7 cells from the roots and rhizomes of Panax ginseng

One new dammarane triterpene saponin named ginsenjilinol (1) was isolated from the roots and rhizomes of Panax ginseng C.A. Mey., together with two known saponins ginsenoside Rf (2) and ginsenoside Re5 ( = panajaponol A, 3). Based on IR, HR-ESI-MS, and 1D as well as 2D NMR ((1)H-(1)H COSY, NOESY, HSQC, and HMBC) spectral data, the chemical structure of the new saponin was elucidated as 3β,12β,20S,26-tetrahydroxydammar-24E-en-6α-O-β-d-glucopyranosyl-(1 → 2)-O-β-d-glucopyranoside. The ability of the isolated saponins to inhibit nitric oxide production by lipopolysaccharide-activated RAW 264.7 cells was also assayed. All of the isolated saponins exhibited the significant activity in a concentration-dependent manner at concentrations of 60-200 μM with the half maximal inhibitory concentration (IC50) values of 70.96 ± 2.05 μM for 1, 74.14 ± 2.65 μM for 2, and 79.83 ± 1.78 μM for 3, respectively, whereas indomethacin had an IC50 of 63.75 ± 3.33 μM as a positive control drug.

Isolation and analysis of ginseng: advances and challenges

Ginseng occupies a prominent position in the list of best-selling natural products in the world. Because of its complex constituents, multidisciplinary techniques are needed to validate the analytical methods that support ginseng's use worldwide. In the past decade, rapid development of technology has advanced many aspects of ginseng research. The aim of this review is to illustrate the recent advances in the isolation and analysis of ginseng, and to highlight new applications and challenges. Emphasis is placed on recent trends and emerging techniques.

Isolation and characterization of a new ginsenoside from the fresh root of Panax Ginseng

A new saponin, malonylginsenoside Ra₃, was isolated from the fresh root of Panax ginseng, along with four known ginsenosides. The new compound was identified as (20S)-protopanaxadiol-3-O-(6-O-malonyl-β-D-glucopyranosyl(1→2)-β-D-glucopyranoside-20-O-β-D-xylopyranosyl(1→3)-β-D-glucopyranosyl(1→6)-β-D-glucopyranoside on the basis of extensive 1D and 2D NMR as well as HRESI-MS spectroscopic data analysis.

Ginsenosides chemistry, biosynthesis, analysis, and potential health effects

Ginsenosides are a special group of triterpenoid saponins that can be classified into two groups by the skeleton of their aglycones, namely dammarane- and oleanane-type. Ginsenosides are found nearly exclusively in Panax species (ginseng) and up to now more than 150 naturally occurring ginsenosides have been isolated from roots, leaves/stems, fruits, and/or flower heads of ginseng. Ginsenosides have been the target of a lot of research as they are believed to be the main active principles behind the claims of ginsengs efficacy. The potential health effects of ginsenosides that are discussed in this chapter include anticarcinogenic, immunomodulatory, anti-inflammatory, antiallergic, antiatherosclerotic, antihypertensive, and antidiabetic effects as well as antistress activity and effects on the central nervous system. Ginsensoides can be metabolized in the stomach (acid hydrolysis) and in the gastrointestinal tract (bacterial hydrolysis) or transformed to other ginsenosides by drying and steaming of ginseng to more bioavailable and bioactive ginsenosides. The metabolization and transformation of intact ginsenosides, which seems to play an important role for their potential health effects, are discussed. Qualitative and quantitative analytical techniques for the analysis of ginsenosides are important in relation to quality control of ginseng products and plant material and for the determination of the effects of processing of plant material as well as for the determination of the metabolism and bioavailability of ginsenosides. Analytical techniques for the analysis of ginsenosides that are described in this chapter are thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) combined with various detectors, gas chromatography (GC), colorimetry, enzyme immunoassays (EIA), capillary electrophoresis (CE), nuclear magnetic resonance (NMR) spectroscopy, and spectrophotometric methods.

Progress in understanding of ginsenoside biosynthesis

Ginseng is an economically important medicinal plant. The major bioactive ingredients of ginseng are ginsenosides, which are triterpene saponins. Because of difficulties in ginseng cultivation and the low productivity of ginseng cell and tissue culture, it has become important to improve ginsenoside levels by using metabolic engineering based on the biosynthetic pathway of ginsenosides. During the last decade, substantial advances have been made in biosynthesis of ginsenosides. This review is concerned with recent developments in our understanding of the biosynthesis of ginsenosides.

Isolation, synthesis and structures of cytotoxic ginsenoside derivatives

Four known ginsenosides: ginsenoside-Rb1 (1), Rb3 (2), Rd (3) and Re (4) were isolated from the methanolic extract of the traditional Chinese medicine Panax ginseng C. A. Meyer. Further enzyme reactions and chemical modifications led us to obtain ginsenoside-M1 (5) and synthesize three novel mono-esters of ginsenoside-M1, ginsenoside-DM1 (6), PM1 (7) and SM1 (8) 30 - 50% of yield via a facile and green synthetic strategy. The structures were elucidated on the basis of extensive 1D- and 2DNMR, as well as high resolution ESI-TOF mass spectroscopic analyses. The isolated and synthetic compounds were tested in an anti-tumor bioassay, and compounds 5-8 showed considerable cytotoxicity (SRB) against several human cancer cell lines (breast cancer MCF-7, skin melanoma SK-MEL-2 and human ovarian carcinoma B16), but moderate effects on lung carcinoma COR-L23. The other ginsenosides showed no effects.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids including squalene derivatives, lanostanes, cycloartanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, uranes, hopanes, isomalabaricanes and saponins. The literature from January to December 2004 is reviewed and 243 references are cited.

Ginsenine, a new alkaloid from the berry of Panax ginseng C. A. Meyer

A new indole alkaloid, ginsenine, with a seven-membered lactam unit, was isolated from the berry of Panax ginseng. Its structure was established on the basis of extensive NMR (1H- and 13C-NMR, 1H-1H COSY, DEPT, HMQC, HMBC), IR, and ESI-MS analysis.