An improved method for the preparation of Ginsenoside Rg5 from ginseng fibrous root powder

Oxidation and Hydrolysis of Ginsenoside Rg5: An Underestimated Degradation Pathway, Isolation, and Characterization of Unknown Degradation Products

Ginsenoside Rg5, a secondary ginsenoside derived from the degradation of protopanaxadiol saponins, exhibits various pharmacological activities, including anticancer, anti-inflammatory, antidiabetic, and memory-enhancing effects, making it a promising candidate for natural medicine. However, research on the stability of Rg5, particularly in aqueous solutions, remains limited. This study systematically investigates the stability of ginsenoside Rg5 in water by monitoring its degradation over time under controlled conditions. The stability of the Rg5 aqueous solution was assessed by investigating the influences of temperature and time, employing high-performance liquid chromatography (HPLC) analysis to evaluate its degradation. The findings indicated substantial degradation of Rg5, with approximately 95% decomposition observed after a period of 10 days. The decomposition products were isolated using preparative liquid chromatography and identified through high-resolution mass spectrometry (HR-MS), NMR, and induced circular dichroism (ICD) analyses. A novel derivative was identified, and its degradation pathway was elucidated, encompassing oxidation, hydrolysis, and dehydration processes that culminated in the formation of four distinct stereoisomers. This study elucidates the instability of Rg5 in aqueous environments and offers significant insights into its decomposition mechanism. The findings emphasize the critical importance of optimizing storage conditions and minimizing exposure to water and oxygen to enhance the stability of Rg5, thereby advancing its potential applications in pharmaceutical development and storage.

Ginsenoside Rg5 as an anticancer drug: a comprehensive review on mechanisms, structure-activity relationship, and prospects for clinical advancement

Cancer remains one of the leading causes of death in the world. Despite the considerable success of conventional treatment strategies, the incidence and mortality rates are still high, making developing new effective anticancer therapies an urgent priority. Ginsenoside Rg5 (Rg5) is a minor ginsenoside constituent obtained exclusively from ginseng species and is known for its broad spectrum of pharmacological activities. This article aimed to comprehensively review the anticancer properties of Rg5, focusing on action mechanisms, structure-activity relationship (SAR), and pharmacokinetics attributes. The in vitro and in vivo activities of Rg5 have been proven against several cancer types, such as breast, liver, lung, bone, and gastrointestinal (GI) cancers. The modulation of multiple signaling pathways critical for cancer growth and survival mediates these activities. Nevertheless, human clinical studies of Rg5 have not been addressed before, and there is still considerable ambiguity regarding its pharmacokinetics properties. In addition, a significant shortage in the structure-activity relationship (SAR) of Rg5 has been identified. Therefore, future efforts should focus on further optimization by performing extensive SAR studies to uncover the structural features essential for the potent anticancer activity of Rg5. Thus, this review highlights the value of Rg5 as a potential anticancer drug candidate and identifies the research areas requiring more investigation.

How to More Effectively Obtain Ginsenoside Rg5: Understanding Pathways of Conversion

Ginsenoside Rg5, a relatively uncommon secondary ginsenoside, exhibits notable pharmacological activity and is commonly hypothesized to originate from the dehydration of Rg3. In this work, we compared different conversion pathways using Rb1, R-Rg3 and S-Rg3 as the raw material under simple acid catalysis. Interestingly, the results indicate that the conversion follows this reaction activity order Rb1 > S-Rg3 > R-Rg3, which is contrary to the common understanding of Rg5 obtained from Rg3 by dehydration. Our experimental results have been fully confirmed by theoretical calculations and a NOESY analysis. The DFT analysis reveals that the free energies of S-Rg3 and R-Rg3 in generating carbocation are 7.56 mol/L and 7.57 mol/L, respectively, which are significantly higher than the free energy of 1.81 mol/L when Rb1 generates the same carbocation. This finding aligns with experimental evidence suggesting that Rb1 is more prone to generating Rg5 than Rg3. The findings from the nuclear magnetic resonance (NMR) analysis suggest that the fatty chains (C22-C27) in R-Rg3 and S-Rg3 adopt a Gauche conformation and an anti conformation with C16-C17 and C13-C17, respectively, due to the relatively weak repulsive van der Waals force. Therefore, the configuration of R-Rg3 is more conducive to the formation of intramolecular hydrogen bonds between 20C-OH and 12C-OH, whereas S-Rg3 lacks this capability. Consequently, this also explains the fact that S-Rg3 is more prone to dehydration to generate Rg5 than R-Rg3. Additionally, our research reveals that the synthetic route of Rg5 derived from protopanaxadiol (PPD)-type ginsenosides (including Rb1, Rb2, Rb3, Rc and Rd) exhibits notable advantages in terms of efficacy, purity and yield when compared to the pathway originating from Rg3. Moreover, this study presents a highly effective and practical approach for the extensive synthesis of Rg5, thereby facilitating the exploration of its pharmacological properties and potential application in drug discovery.

Green and Efficient Extraction of Polysaccharide and Ginsenoside from American Ginseng (Panax quinquefolius L.) by Deep Eutectic Solvent Extraction and Aqueous Two-Phase System

In this study, a green and effective extraction method was proposed to extract two main compounds, ginsenosides and polysaccharides, from American ginseng by combining deep eutectic solvents (DESs) with aqueous two-phase systems. The factors of type of DESs, water content in DESs, the solid–liquid ratio, extraction temperature, and extraction time were studied in the solid–liquid extraction. Then, the aqueous two-phase system (DESs-ethylene oxide–propylene oxide (EOPO)) and salty solution exchange (EOPO-salty solution) was applied for the purification of polysaccharides. The content of the polysaccharides and ginsenosides were analyzed by the anthrone–sulfuric acid method and HPLC method, which showed that the extraction efficiency of deep eutectic solvents (DESs) was better than conventional methods. Moreover, the antioxidant activities of ginseng polysaccharides and their cytotoxicity were further assayed. The advantages of the current study are that, throughout the whole extraction process, we avoided the usage of an organic reagent. Furthermore, the separated green solvent DESs and EOPO could be recovered and reused for a next cycle. Thus, this study proposed a new, green and recyclable extraction method for extracting ginsenosides and polysaccharides from American ginseng.

20(22)Z and 20(22)E Dammarane Saponins From the Roots of Panax pseudoginseng Wall

Panax pseudoginseng Wall. is famous as a traditional Vietnamese medicinal plant used to promote health and aid in cancer treatment. From the roots of this plant, 1 new (1) and 4 known (2-5) Δ20(22)-dammarane-type triterpenoid glycosides were isolated by various chromatographic methods. Their chemical structures were determined as 3β,6α,12β-trihydroxydammarane-( Z)-20(22),24-diene 6 -O-β-D-glucopyranoside (1), 3β,6α,12β-trihydroxy-dammar-( E)-20(22),25-diene 6 -O-β-D-glucopyranoside (2, ginsenoside Rh4), ginsenoside Rg5 (3), 3β,12β-dihydroxydammarane-( E)-20(22),24-diene 6 -O-β-D-xylopyranosyl-(1→2)-β-D-glucopyranoside (4), and 3β,12β-dihydroxydammarane-( E)-20(22),24-diene 6 -O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (5). The E/ Z-Δ20(22) configurations in the dammarane compounds were further evidenced by 1D and 2D NMR data.

An Efficient Synthesis of Ginsenoside Rg5 via Conversion of PPD Type Saponins: Unusual Application of 4A Molecular Sieves

Ginsenoside Rg5 is a rare secondary ginsenoside with good pharmacological activity. However, preparation of Rg5 is time consuming, gives a low yield and has poor selectivity and efficiency. Therefore, the current study describes an efficient method of preparing ginsenoside Rg5 through conversion of Protopanaxadiol (PPD) type saponins in the presence of a molecular sieve and hydrochloric acid. The PPD type saponins were transformed on the surface of a molecular sieve to obtain ginsenoside Rg5 and most of the generated secondary ginsenoside was dissociates into the reaction solution, avoiding further decomposition. In addition, the optimal experimental conditions were identified to be as follows; 0.5 ml of absolute ethanol, 0.2 mol/L of hydrochloric acid, 12.5 mg of a 4A molecular sieve, a reaction time of 2.5 hours and a reaction temperature of 70 ℃. Under these experimental conditions, yields of upto 63.2% were obtained for ginsenoside Rg5. Moreover, the hydrochloric acid-catalyzed preparation of ginsenoside Rg5 effectively inhibited its decomposition in the presence of a molecular sieve. The method is therefore suitable for laboratory and industrial production with the advantages of large-scale preparation and high-yield.

Advances in the Production of Minor Ginsenosides Using Microorganisms and Their Enzymes

Abstract Minor ginsenodes are of great interest due to their diverse pharmacological activities such as their anti-cancer, anti-diabetic, neuroprotective, immunomodulator, and anti-inflammatory effects. The miniscule amount of minor ginsenosides in ginseng plants has driven the development of their mass production methods. Among the various production methods for minor ginsenosides, the utilization of microorganisms and their enzymes are considered as highly specific, safe, and environmentally friendly. In this review, various minor ginsenosides production strategies, namely utilizing microorganisms and recombinant microbial enzymes, for biotransforming major ginsenosides into minor ginsenoside, as well as constructing synthetic minor ginsenosides production pathways in yeast cell factories, are described and discussed. Furthermore, the present challenges and future research direction for producing minor ginsenosides using those approaches are discussed.

Panax quinquefolium L. Ginsenosides from Hairy Root Cultures and Their Clones Exert Cytotoxic, Genotoxic and Pro-Apoptotic Activity towards Human Colon Adenocarcinoma Cell Line Caco-2

American ginseng, Panax quinquefolium (L.), is traditionally used in folk medicine. It exhibits a range of anti-inflammatory, hepatoprotective, anti-diabetic, anti-obesity, anti-hyperlipidemic and anti-carcinogenic effects. Its main components are ginsenosides, also known as panaxosides or triterpene saponins. In order to obtain high yields of ginsenosides, different methods of controlled production are involved, i.e., with hairy root cultures. However, they are still employed under in vitro conditions. Our studies revealed that hairy root cultures subjected to an elicitation process can be considered as a potent source of ginsenosides. The present study examines the biological activity of ginseng hairy root cultures against the Caco-2 human adenocarcinoma cell line. Among our six different clones of P. quinquefolium hairy roots, extracts B and Be (treated with elicitor) were the strongest inhibitors of the cellular metabolic activity. While all extracts induced DNA damage, B and Be also generated reactive oxygen species (ROS) in a concentration-dependent manner, which was correlated with the depletion of the mitochondrial membrane potential and induction of apoptosis. These findings indicate that further research concerning P. quinquefolium hairy root cultures should focus on the activity of rare ginsenosides and other biologically active compound profiles (i.e., phenolic compounds).