Dammarane-type Triterpene Research Articles

Eight new dammarane-type triterpenoid saponins from Gynostemma pentaphyllum

Phytochemical investigation of Gynostemma pentaphyllum led to the purification of five novel dammarane-type triterpene isolates, gypenosides B1 − B5 (1–5). Their structures were determined through comprehensive 1D and 2D NMR spectroscopic analyses and HRESIMS data. Of note, 1–3 are inseparable mixtures of epimers due to their unstable nature, and a total of eight dammarane-type triterpene saponins were identified. Additionally, the protective activities of these new compounds against PC12 cell injury induced by hypoxia were evaluated.

Methyl jasmonate inducible UGT79A18 is a novel glycosyltransferase involved in the bacoside biosynthetic pathway in Bacopa monnieri.

Bacosides are dammarane-type triterpenoidal saponins in Bacopa monnieri and have various pharmacological applications. All the bacosides are diversified from two isomers, i.e., jujubogenin and pseudojujubogenin. The biosynthetic pathway of bacoside is not well elucidated. In the present study, we characterized a UDP-glycosyltransferase, UGT79A18, involved in the glycosylation of pseudojujubogenin. UGT79A18 shows higher expression in response to 5 h of wounding, and 3 h of MeJA treatment. The recombinant UGT79A18 shows in vitro activity against a wide range of flavonoids and triterpenes and has a substrate preference for protopanaxadiol, a dammarane-type triterpene. Secondary metabolite analysis of overexpression and knockdown lines of UGT79A18 in B. monnieri identify bacopasaponin D, bacopaside II, bacopaside N2 and pseudojujubogenin glucosyl rhamnoside as the major bacosides that were differentially accumulated. In the overexpression lines of UGT79A18, we found 1.7-fold enhanced bacopaside II, 8-fold enhanced bacopasaponin D, 3-fold enhanced pseudojujubogenin glucosyl rhamnoside, and 1.6-fold enhanced bacopaside N2 content in comparison with vector control plant, whereas in the knockdown lines of UGT79A18, we found 1.4-fold reduction in bacopaside II content, 3-fold reduction in the bacopasaponin D content, 2-fold reduction in the pseudojujubogenin glucosyl rhamnoside content, and 1.5-fold reduction in bacopaside N2 content in comparison with vector control. These results suggest that UGT79A18 is a significant UDP glycosyltransferase involved in glycosylating pseudojujubogenin and enhancing the pseudojujubogenin-derived bacosides.

Polysciasoside B and C: new dammarane-type triterpene glycosides from the leaves of Australian rainforest plant Polyscias australiana (F.Muell.) Philipson (Araliaceae)

Phytochemical investigation of the leaves of Polyscias australiana (F.Muell.) Philipson (family Araliaceae) led to the isolation and identification of two new analogues belonging to the rare dammarane-type triterpene glycosides, polysciasosides B (1) and C (2). Also isolated in high yields from this plant was the known saponin, β-hedrin (3). The two new polysciasoside analogues exhibited no anti-inflammatory activity (inhibitory effects on NO inhibition and cell viability in RAW 264.7 macrophages) or cytotoxic activity against AGS gastric adenocarcinoma or the MCF7 breast adenocarcinoma cell lines. In contrast, the known compound β-hedrin exhibited potent anti-inflammatory and cytotoxicity in these biological assays.

Dammarane-type triterpene saponins from the roots of Panax notoginseng (Burk.) F. H. Chen and their neuroprotective effects

Three undescribed dammarane-type triterpene saponins, 20(S)-sanchirhinoside A7-A9 (1–3), together with seventeen known ones, were isolated from the roots of Panax notoginseng (Burk.) F. H. Chen. The chemical structures of the new compounds were determined by HR-MS and NMR experiments along with chemical methods. To the best of our knowledge, compound 1 was the firstly reported fucose-containing triterpene saponin from plants in the genus of Panax. Moreover, the in vitro neuroprotective effects of the isolated compounds were evaluated. Compounds 11–12 displayed remarkable protective effects against PC12 cells injured by 6-hydroxydopamine.

Ginsenoside Rb1 promotes the activation of PPARα pathway via inhibiting FADD to ameliorate heart failure

PurposeGinsenoside Rb1 (GRb1), a dammarane-type triterpene saponin compound mainly distributed in ginseng (Panax ginseng), has been demonstrated to ameliorate cardiovascular diseases. However, it remains unclear whether GRb1 alleviates heart failure (HF) by maintaining cardiac energy metabolism balance. Therefore, this work aimed to investigate the cardiac benefits of GRb1 against cardiac energy deficit and explore its mechanism of action. Methods and resultsIsoproterenol (ISO) induced HF Sprague–Dawley rats were administrated with GRb1 or fenofibrate for 6 weeks. ISO-induced primary neonatal rat cardiomyocytes (NRCMs) were used as the in vitro model. In vivo, GRb1 significantly improved the structural and metabolic disorder, as demonstrated by the restoration of cardiac function, inhibition of cardiac hypertrophy and fibrosis, and increased adenosine triphosphate (ATP) generation. In vitro, GRb1 effectively protected mitochondrial function and scavenged excessive reactive oxygen species. Moreover, in ISO-induced NRCMs, GRb1 significantly inhibited the abnormal upregulation of Fas-associated death domain (FADD), promoted transcriptional activation of peroxisome proliferator-activated receptor-alpha (PPARα), improved the aberrant expression of cardiac energy metabolism-related enzymes and cardiac fatty acid oxidation, and subsequently increased the synthesis of ATP. Noticeably, GRb1 could inhibit the increased binding between FADD and PPARα, which contributed to the activation of PPARα. Furthermore, GRb1 strengthened the thermal stabilization of FADD and might bind to FADD directly. ConclusionsCollectively, it’s part of the in-depth mechanism of GRb1’s cardio-protection that GRb1 could directly bind to FADD and counteract its negative role in the transcription of PPARα thus ameliorating cardiac energy derangement and HF.

Comparative genomics reveals the diversification of triterpenoid biosynthesis and origin of ocotillol-type triterpenes in Panax

Gene duplication is assumed to be the major force driving the evolution of metabolite biosynthesis in plants. Freed from functional burdens, duplicated genes can mutate toward novelties until fixed due to selective fitness. However, the extent to which this mechanism has driven the diversification of metabolite biosynthesis remains to be tested. Here we performed comparative genomics analysis and functional characterization to evaluate the impact of gene duplication on the evolution of triterpenoid biosynthesis using Panax species as models. We found that whole-genome duplications (WGDs) occurred independently in Araliaceae and Apiaceae lineages. Comparative genomics revealed the evolutionary trajectories of triterpenoid biosynthesis in plants, which was mainly promoted by WGDs and tandem duplication. Lanosterol synthase (LAS) was likely derived from a tandem duplicate of cycloartenol synthase that predated the emergence of Nymphaeales. Under episodic diversifying selection, the LAS gene duplicates produced by γ whole-genome triplication have given rise to triterpene biosynthesis in core eudicots through neofunctionalization. Moreover, functional characterization revealed that oxidosqualene cyclases (OSCs) responsible for synthesizing dammarane-type triterpenes in Panax species were also capable of producing ocotillol-type triterpenes. Genomic and biochemical evidence suggested that Panax genes encoding the above OSCs originated from the specialization of one OSC gene duplicate produced from a recent WGD shared by Araliaceae (Pg-β). Our results reveal the crucial role of gene duplication in diversification of triterpenoid biosynthesis in plants and provide insight into the origin of ocotillol-type triterpenes in Panax species.

Six new dammarane-type triterpene saponins from the processed leaves of Panax notoginseng

Six new dammarane-type triterpenoid saponins, notoginsenosides SFt 5 –SFt 10 ( 1 – 6 ) were isolated from the processed leaves of Panax notoginseng (Burk.) F.H.Chen (Araliaceae), together with eight known notoginsenosides ( 7 – 14 ), fourteen known ginsenosides ( 15 − 28 ), two known vinaginsenosides ( 29 − 30 ), and one known gypenoside ( 31 ). Their structures were established by detailed spectroscopic analysis (NMR, UV, IR, HRESI-MS) and acidic hydrolysis. Four compounds notoginsenoside SFt 1 ( 7 ), ginsenosides Rg 5 ( 17 ), C-Mc ( 23 ) and 20( R )–Rg 3 ( 25 ) have significant protective effects against L -glutamate-induced SH–SY5Y nerve injury (10 μ M). • Six new triterpenoid saponins were isolated from Panax notoginseng. • Their structures were established by detailed spectroscopic analyses and acidic hydrolysis. • Four compounds demonstrated significant protective effects against L -glutamate-induced SH–SY5Y nerve injury.

Gypensapogenin H suppresses tumor growth and cell migration in triple-negative breast cancer by regulating PI3K/AKT/NF-κB/MMP-9 signaling pathway

Due to its aggressiveness and high metastasis rates, triple-negative breast cancer (TNBC) is a ubiquitous and deadly disease for the majority of women globally. Gypensapogenin H (GH) is a novel dammarane-type triterpene isolated from hydrolyzate of total saponins from Gynostemma pentaphyllum. Our previous work demonstrated that GH promoted apoptosis in TNBC. In the present study, xenograft TNBC models (xenotransplantation of MDA-MB-231 cells in nude mice) were used to evaluate the efficacy of GH in vivo. We preliminarily predicted the mechanism of GH inhibiting breast cancer tumors at the gene level through transcriptome screening. Through western blot analysis of tumor tissue, we found that GH could inhibit tumor proliferation and migration by regulating the PI3K/AKT/NF-κB/MMP-9 signaling pathway in vivo. We also analyzedthe results at the cell level in vitro, which were consistent with those in vivo. In summary, GH inhibited TNBC growth in vivo and suppressed TNBC cell migration in vitro. Our findings could help understand the mechanism of action of GH and suggest that GH would be a promising agent for TNBC therapy.

Isolation, identification, and quantification of triterpene saponins in the fresh fruits of Panax notoginseng

This study is to develop a method for isolation, identification, and quantitative determination of dammarane-type triterpene saponins in the Panax notoginseng fruits (PNF). The saponins were isolated by a serious of chromatographic methods, and their structures were elucidated on the basis of spectroscopic evidence and comparison with those of literature reports. Quantitative assay was performed on an ultra-performance liquid chromatography-UV (UPLC-UV) method. As a result, 22 saponins were isolated from the extract of PNF, among them, compound 1 was a new saponin, named as malonylgypenoside IX, compounds 3–10, and 14–18 were isolated from the PNF for the first time. As to quantitative analysis, the calibration curves showed good linearity (r > 0.998) within the concentration range, and the method validation provided good reproducibility and sensitivity for the quantification of eight major saponins with precision and accuracy of less than 3.0%.

Characteristic Malonyl Ginsenosides from the Leaves of Panax notoginseng as Potential Quality Markers for Adulteration Detection.

Due to the high price and limited supply of Panax notoginseng, a large number of samples adulterated with the leaves appear in the market. A group of new malonyl ginsenosides were exclusively detected in the P. notoginseng leaves (PNL). Targeted isolation of the malonyl ginsenosides was guided by UPLC-QDa MS. HRMS, 1D/2D NMR, and chemical methods were used for structural identification. A selected ion monitoring method was developed based on UPLC-QDa MS to detect the adulterations. In addition, the anti-inflammatory activities and the collision-induced dissociation features of the isolated saponins were studied. As a result, eight new 3-OH malonylated dammarane-type triterpene oligoglycosides (notoginsenosides L3-L10) were obtained from PNL. Adulteration with PNL can be easily detected with limit of detection as low as 0.06%. To sum up, the isolated ginsenosides can be used as quality markers for fraud detection, which will promote the quality control of the notoginseng products.

Hovenia dulcis Thumberg: Phytochemistry, Pharmacology, Toxicology and Regulatory Framework for Its Use in the European Union.

Hovenia dulcis Thunberg is an herbal plant, belonging to the Rhamnaceae family, widespread in west Asia, USA, Australia and New Zealand, but still almost unknown in Western countries. H. dulcis has been described to possess several pharmacological properties, such as antidiabetic, anticancer, antioxidant, anti-inflammatory and hepatoprotective, especially in the hangover treatment, validating its use as an herbal remedy in the Chinese Traditional Medicine. These biological properties are related to a variety of secondary metabolites synthesized by the different plant parts. Root, bark and leaves are rich of dammarane-type triterpene saponins; dihydrokaempferol, quercetin, 3,3′,5′,5,7-pentahydroflavone and dihydromyricetin are flavonoids isolated from the seeds; fruits contain mainly dihydroflavonols, such as dihydromyricetin (or ampelopsin) and hovenodulinol, and flavonols such as myricetin and gallocatechin; alkaloids were found in root, barks (frangulanin) and seeds (perlolyrin), and organic acids (vanillic and ferulic) in hot water extract from seeds. Finally, peduncles have plenty of polysaccharides which justify the use as a food supplement. The aim of this work is to review the whole scientific production, with special focus on the last decade, in order to update phytochemistry, biological activities, nutritional properties, toxicological aspect and regulatory classification of H. dulcis extracts for its use in the European Union.

Characterization of a Novel Ginsenoside MT1 Produced by an Enzymatic Transrhamnosylation of Protopanaxatriol-Type Ginsenosides Re.

Background: Ginsenosides, triterpene saponins of Panax species, are considered the main active ingredients responsible for various pharmacological activities. Herein, a new protopanaxatriol-type ginsenoside called “ginsenoside MT1” is described; it was accidentally found among the enzymatic conversion products of ginsenoside Re. Method: We analyzed the conversion mechanism and found that recombinant β-glucosidase (MT619) transglycosylated the outer rhamnopyranoside of Re at the C-6 position to glucopyranoside at C-20. The production of MT1 by trans-rhamnosylation was optimized and pure MT1 was obtained through various chromatographic processes. Results: The structure of MT1 was elucidated based on spectral data: (20S)-3β,6α,12β,20-tetrahydroxydammarene-20-O-[α-L-rhamnopyranosyl(1→2)-β-D-glucopyranoside]. This dammarane-type triterpene saponin was confirmed as a novel compound. Conclusion: Based on the functions of ginsenosides with similar structures, we believe that this ginsenoside MT1 may have great potential in the development of nutraceutical, pharmaceutical or cosmeceutical products.

Terpenoids and phytosteroids isolated from Commelina benghalensis Linn. with antioxidant activity.

Background Commelina benghalensis Linn. (Family: Commelinaceae) is a common weed available in Bangladesh with several uses in traditional medicine. However, the chemical profile of this medicinal plant is scarce in relation to its medicinal uses. The aerial parts of this plant have been investigated for the isolation of secondary metabolites and evaluation of the biological activities. Methods Major phytochemical groups were analyzed using chromogenic reagents, whereas n-hexane soluble fractionates of the methanol extract were subjected to 1H nuclear magnetic resonance (NMR) spectroscopic analysis. The antioxidant property of the obtained compounds was evaluated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH). Results Dammara-12-en-3-one (CB-1), stigmasterol (CB-2) and 3 (2,3,4,5,6-pentahydroxy)-cinnamoyl dammara-12-ene (CB-3) were isolated from the n-hexane fractionate of methanol extract of C. benghalensis. In the study of DPPH radical scavenging activity, IC50 values were predicted to be 790.18, 4186.94 and 2001.16 μg/mL for CB-1, CB-2 and CB-3, respectively, whereas standard ascorbic acid showed IC50 at 1.26 μg/mL. Conclusions Two new dammarane-type triterpene (CB-1 and CB-3) and one phytosterol (CB-2) were identified in C. benghalensis with mild antioxidant property.

New hydroperoxylated and 20,24-epoxylated dammarane triterpenes from the rot roots of Panax notoginseng

BackgroundRoot rot is a serious destructive disease of Panax notoginseng, a famous cultivated araliaceous herb called Sanqi or Tianqi in Southwest China. MethodsThe chemical substances of Sanqi rot roots were explored by chromatographic techniques. MS, 1D/2D-NMR, and single crystal X-ray diffraction were applied to determine the structures. Murine macrophage RAW264.7 and five human cancer cell lines were used separately for evaluating the antiinflammatory and cytotoxic activities. Results and ConclusionThirty dammarane-type triterpenes and saponins were isolated from the rot roots of P. notoginseng. Among them, seven triterpenes, namely, 20(S)-dammar-25-ene-24(S)-hydroperoxyl-3β,6α,12β,20-tetrol (1), 20(S)-dammar-3-oxo-23-ene-25-hydroperoxyl-6α,12β,20-triol (2), 20(S)-dammar-12-oxo-23-ene-25-hydroperoxyl-3β,6α,20-triol (3), 20(S)-dammar-3-oxo-23-ene-25-hydroperoxyl-12β,20-diol (4), 20(S),24(R)-epoxy-3,4-seco-dammar-25-hydroxy-12-one-3-oic acid (5), 20(S),24(R)-epoxy-3,4-seco-dammar-25-hydroxy-12-one-3-oic acid methyl ester (6), and 6α-hydroxy-22,23,24,25,26,27-hexanordammar-3,12,20-trione (7), are new compounds. In addition, 12 known ones (12–16 and 19–25) were reported in Sanqi for the first time. The new Compound 1 showed comparable antiinflammatory activity on inhibition of NO production to the positive control, whereas the known compounds 9, 12, 13, and 16 displayed moderate cytotoxicities against five human cancer cell lines. The results will provide scientific basis for understanding the chemical constituents of Sanqi rot roots and new candidates for searching antiinflammatory and antitumor agents.

Chemical Constituents from Stems of Pileostegia viburnoides

Phytochemical investigation on the stems of Pileostegia viburnoides Hook.f.et Thoms led to the isolation of twelve compounds, including two steroids (1 and 10), two fatty compounds (2 and 12), seven triterpenoids (3–9), and one coumarin glycoside (11). 24-methylene-5α-dammara-20(21)-en-3β-yl acetate (5), a rare dammarane-tetracyclic triterpene had been first reported just according to the typical 1H-NMR signals analysis, melting point and optical rotation in 1975. However, the complete and reliable NMR and mass data were still unknown. This is the first time to identify the planar and spatial structures of compound 5 by the analysis of 1D-, 2D-NMR, mass data and other physicochemical properties, as well as by comparison of the spectral data with the literature. Further more, the anti-inflammatory and anti-neuroinflammatory activities of dammarane-type triterpenes 4 and 5 were evaluated.

Triterpene saponins in Panax japonicus and their ~(13)C-NMR spectroscopic characteristics

Panax japonicus( PJ) is a valuable medicinal plant belonging to the genus Panax of Araliaceae,the recumbent rhizome of which is widely used in clinic therapy,healthcare products and as cosmetic additives with functions of dissipating stasis,reducing swelling,stanching bleeding,and reinforcing deficiency,etc. PJ contains abundant levels of oleanane-and dammarane-type triterpene saponins,which are considered as the material basis for exerting pharmacodynamic action. Based on the previous researches,more than110 triterpene saponins have been reported from PJ. These triterpene saponins were summarized in this review,and could be classified into dammarenediol Ⅱ,protopanaxadiol,protopanaxatiol,ocotillol,oleanolic acid,ursolic acid and miscellaneous subtypes,according to their molecular skeletons in biosynthesis processes. Further more,the structural features of these triterpene saponins in the seven different subtypes,together with their~(13)C-NMR spectroscopic characteristics were described,hoping to provide available information for chemical diversity research of PJ.

Six new dammarane-type triterpene saponins from Panax ginseng flower buds and their cytotoxicity

BackgroundPanax ginseng has been used for a variety of medical purposes in eastern countries for more than two thousand years. From the extensive experiences accumulated in its long medication use history and the substantial strong evidence in modern research studies, we know that ginseng has various pharmacological activities, such as antitumor, antidiabetic, antioxidant, and cardiovascular system–protective effects. The active chemical constituents of ginseng, ginsenosides, are rich in structural diversity and exhibit a wide range of biological activities. MethodsGinsenoside constituents from P. ginseng flower buds were isolated and purified by various chromatographic methods, and their structures were identified by spectroscopic analysis and comparison with the reported data. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H- tetrazolium bromide method was used to test their cytotoxic effects on three human cancer cell lines. ResultsSix ginsenosides, namely 6'–malonyl formyl ginsenoside F1 (1), 3β–acetoxyl ginsenoside F1 (2), ginsenoside Rh24 (6), ginsenoside Rh25 (7), 7β–hydroxyl ginsenoside Rd (8) and ginsenoside Rh26 (10) were isolated and elucidated as new compounds, together with four known compounds (3–5 and 9). In addition, the cytotoxicity of these isolated compounds was shown as half inhibitory concentration values, a tentative structure–activity relationship was also discussed based on the results of our bioassay. ConclusionThe study of chemical constituents was useful for the quality control of P. ginseng flower buds. The study on antitumor activities showed that new Compound 1 exhibited moderate cytotoxic activities against HL-60, MGC80-3 and Hep-G2 with half inhibitory concentration values of 16.74, 29.51 and 20.48 μM, respectively.

APPLICATION OF ELICITOR FOR PRODUCTION OF SAPONINS FROM IN VITRO PANAX CULTURES

The Panax ginseng species are traditional medicinal herbs having high value. The major pharmacologically active components are the ginsenosides of saponin group, which are dammarane type triterpene glycosides containing a tetracyclic glycose. Ginseng saponin, one of the secondary metabolites, is necessary for the growth and development of Panax genus plants. In pharmaceutical industry, triterpene saponins were purified to produce drugs for its promising healing and restorative properties. However, commercial applications are still obstacle for practical problems, because ginseng natural resources are rarely precious; and ginseng resources from field have low and variable yields dependent on season or quality of soil. Moreover, triterpene saponins have complex structures, making chemical synthesis an economically uncompetitive option for large-scale production. A current alternative optimal solution that is popular in the world is the application of cell and tissue culture to produce a large of cell or root yield in short time. But the difficulty in producing triterpene saponins from in vitro culture is that the triterpene saponin content is much lower than natural. To increase the triterpene saponin content, elicitors are added to the culture medium. Based on the effect of the elicitor, metabolic engineering in vitro is also able to enhance the overexpression of genes which translated enzymes or signals producing saponin in the isoprenoid pathway. Application of elicitor researches could improve triterpene saponin yields or adjust specific desired triterpene saponins from in vitro ginseng culture. Therefore, we review the recent studies of elicitor in Panax genus cultures and saponin biosynthetic gene to study and assess the efficiency of elicitors in triterpene saponin production and metabolic engineering of triterpene saponins.

Gypensapogenin H from hydrolyzate of total Gynostemma pentaphyllum saponins induces apoptosis in human breast carcinoma cells

Gypensapogenin H (Gyp H) is a novel dammarane-type triterpene, isolated from hydrolyzate of total saponins from Gynostemma pentaphyllum. Our previous work demonstrated that Gyp H exhibited potent growth inhibitory effects on tumor cells. It significantly inhibited the growth of human breast cancer cells (MDA-MB-231), while having low toxicity to normal human breast epithelial cells, MCF-10a. Further mechanistic study demonstrated that Gyp H decreased survival, inhibited proliferation, migration, induced apoptosis and led to cell cycle arrest. For the MDA-MB-231 cell lines, Gyp H increased expression of P21, Bax and cytochrome c, induced PARP cleavage and activated caspases. Gyp H also reduced expression of CDK2/4, CyclinD1, E2F1 and Bcl2, which associated with the cell cycle arrest. Thus, our finding may be useful for understanding the mechanism of action of Gyp H on breast cancer cells and suggest that Gyp H would be a leading agent for the treatment of breast cancer.

Influence of new effective allelochemicals on the distribution of Cleome arabica L. community in nature

New allelochemicals were identified through bio-guided fractionation from the ethyl acetate of seeds extracts, which was the most autotoxic compared to the other plant parts. Phytochemical investigation of the seeds extracts of C. arabica by spectroscopy analyses has led to identify two new dammarane type triterpenes (4 and 9), with nine known analogues (1 − 3, 5 − 8, 10 and 11), a new cucurbitane triterpene (12), acylated dehydrodiconiferyl alcohol (13), and three highly oxygenated flavonols (14−16). The most autotoxic compounds on germination and seedling growth were elucidated as dammarane type triterpenes. However, less autotoxic effect was recorded by an inhibition under 50% for most of the identified flavonoids. These results suggest that those autotoxic substances may be used as a new bio-herbicide that may contribute to manage the distribution of C. arabica in agronomic field.