Novel dammarane-type glycosides from Gynostemma pentaphyllum

Dammarane-type triterpenoids from Gynostemma longipes and their protective activities on hypoxia-induced injury in PC12 cells

Sixteen new dammarane-type triterpenoid saponins (1-16) featuring diverse structural variations in the side chain at C-17, along with twenty-one known analogues (17-37), have been isolated from the rhizomes of Gynostemma longipes C. Y. Wu, a plant renowned for its medicinal and edible properties. The structural elucidation of these compounds was accomplished through comprehensive analyses of 1D and 2D NMR and HRMS spectroscopic data, supplemented by comparison with previously reported data. Subsequent assays on the isolates for their protective effects against hypoxia-induced damage in pheochromocytoma cells (PC12 cells) revealed that nine saponins exhibited significant anti-hypoxic activities. Further investigation into the anti-hypoxia mechanisms of the representative saponins demonstrated that compounds 22 and 36 markedly reduced the levels of hypoxia-induced apoptosis. Additionally, these compounds were found to decrease the release of lactate dehydrogenase (LDH) and malondialdehyde (MDA), while increasing the activity of superoxide dismutase (SOD), thereby indicating that the saponins could mitigate hypoxia-induced injuries by ameliorating apoptosis and oxidative stress. These findings offer substantial evidence for the future utilization and development of G. longipes, identifying dammarane-type triterpenoid saponins as its active anti-hypoxic constituents.

Diploid chromosome-level reference genome and population genomic analyses provide insights into Gypenoside biosynthesis and demographic evolution of Gynostemma pentaphyllum (Cucurbitaceae)

Gynostemma pentaphyllum (Thunb.) Makino is a perennial creeping herbaceous plant in the family Cucurbitaceae, which has great medicinal value and commercial potential, but urgent conservation efforts are needed due to the gradual decreases and fragmented distribution of its wild populations. Here, we report the high-quality diploid chromosome-level genome of G. pentaphyllum obtained using a combination of next-generation sequencing short reads, Nanopore long reads, and Hi-C sequencing technologies. The genome is anchored to 11 pseudo-chromosomes with a total size of 608.95 Mb and 26 588 predicted genes. Comparative genomic analyses indicate that G. pentaphyllum is estimated to have diverged from Momordica charantia 60.7 million years ago, with no recent whole-genome duplication event. Genomic population analyses based on genotyping-by-sequencing and ecological niche analyses indicated low genetic diversity but a strong population structure within the species, which could classify 32 G. pentaphyllum populations into three geographical groups shaped jointly by geographic and climate factors. Furthermore, comparative transcriptome analyses showed that the genes encoding enzyme involved in gypenoside biosynthesis had higher expression levels in the leaves and tendrils. Overall, the findings obtained in this study provide an effective molecular basis for further studies of demographic genetics, ecological adaption, and systematic evolution in Cucurbitaceae species, as well as contributing to molecular breeding, and the biosynthesis and biotransformation of gypenoside.

Enzymatic Biotransformation of Gypenoside XLIX into Gylongiposide I and Their Antiviral Roles against Enterovirus 71 In Vitro

Biotransformation of specific saponins in the valuable medical plants to increase their bioavailability and pharmaceutical activities has attracted more and more attention. A gene encoding a thermophilic glycoside hydrolase from Fervidobaterium pennivorans DSM9078 was cloned and expressed in Escherichia coli. The purified recombinant enzyme, exhibiting endoglucanase cellulase activity, was used to transform gypenoside XLIX into gylongiposide I via highly selective and efficient hydrolysis of the glucose moiety linked to the C21 position in gypenoside XLIX. Under the optimal reaction conditions for large scale production of gylongiposide I, 35 g gypenoside XLIX was transformed by using 20 g crude enzyme at pH 6.0 and 80 °C for 4 h with a molar yield of 100%. Finally, 11.51 g of gylongiposide I was purified using a silica gel column with 91.84% chromatographic purity. Furthermore, inhibitory activities of gypenoside XLIX and gylongiposide I against Enterovirus 71 (EV71) were investigated. Importantly, the EC50 of gypenoside XLIX and gylongiposide I calculated from viral titers in supernatants was 3.53 μM and 1.53 μM, respectively. Moreover, the transformed product gylongiposide I has better anti-EV71 activity than the glycosylated precursor. In conclusion, this enzymatic method would be useful in the large-scale production of gylongiposide I, which would be a novel potent anti-EV71 candidate.

Antioxidant, Hypoglycemic and Molecular Docking Studies of Methanolic Extract, Fractions and Isolated Compounds from Aerial Parts of Cymbopogon citratus (DC.) Stapf

Traditionally, Cymbopogon citratus is used to treat a variety of ailments, including cough, indigestion, fever, and diabetes. The previous chemical and bioactive research on C. citratus mainly focused on its volatile oil. In this study, 20 non-volatile known compounds were isolated from the dried aerial part of C. citratus, and their structures were elucidated by MS, NMR spectroscopy, and comparison with the published spectroscopic data. Among them, 16 compounds were reported for the first time from this plant. The screening results for antioxidant and α-glucosidase inhibitory activities indicated that compounds caffeic acid (5), 1-O-p-coumaroyl-3-O-caffeoylglycerol (8), 1,3-O-dicaffeoylglycerol (9) and luteolin-7-O-β-D-glucopyranoside (12) had potent antioxidant capacities, with IC₅₀ values from 7.28 to 14.81 μM, 1.70 to 2.15 mol Trolox/mol and 1.31 to 2.42 mol Trolox/mol for DPPH, ABTS, and FRAP, respectively. Meanwhile, compounds 8 and 9 also exhibited significant inhibitory activities against α-glucosidase, with IC₅₀ values of 11.45 ± 1.82 μM and 5.46 ± 0.25 μM, respectively, which were reported for the first time for their α-glucosidase inhibitory activities. The molecular docking result provided a molecular comprehension of the interaction between compounds (8 and 9) and α-glucosidase. The significant antioxidant and α-glucosidase inhibitory activities of compounds 8 and 9 suggested that they could be developed into antidiabetic drugs because of their potential regulatory roles on oxidative stress and digestive enzyme.

Chemical Constituents from the Leaves of Pachyrhizus erosus Collected in Vietnam

A phytochemical investigation of methanol extract from leaves of Pachyrhizus erosus (L.) Urban, a leguminous shrub distributed in Vietnam and other tropical and subtropical countries led to the isolation of a new prenylated chalcone, erosusone (1) and a new megastigmane glycoside epimer, 3-episedumoside F₁ (9), together with thirteen known compounds including flavonoids (2-6), a 3-benzoxepine lactone (7), a pyridine-4,5-diol derivative (8), megastigmanes and megastigmane glycosides (10-15). Their structures were elucidated by means of high resolution-electrospray ionization (HR-ESI)-MS, one dimensional (1D) and two-dimensional NMR (2D-NMR) spectroscopy as well as comparison with the data reported in the literature. The cytotoxic effects on LU-1 (lung carcinoma), HepG2 (hepatocellular carcinoma), and MCF7 (breast carcinoma) cell lines were assessed. Prenylated chalcones 1-2 and isoflavone 3 exhibited cytotoxicity against all tested cell lines with IC₅₀ values ranging from 22.04 to 45.03 µM.

Antioxidant, Anti-Inflammatory, and Antidiabetic Activities of Bioactive Compounds from the Fruits of Livistona chinensis Based on Network Pharmacology Prediction

In this study, a chemical investigation on the fruits of Livistona chinensis (FLC) led to the isolation and identification of 45 polyphenols and 5 alkaloids, including two new compounds (Livischinol (1) and Livischinine A (46)), an undescribed compound (47) and 47 known compounds. FLC was predicted with novel potential antidiabetic function by collecting and analyzing the potential targets of the ingredients. Compound 32 exhibited significant α-glucosidase inhibitory activity (IC₅₀ = 5.71 μM) and 1, 6, and 44 showed the PTP1B inhibitory activity with IC₅₀ values of 9.41-22.19 μM, while that of oleanolic acid was 28.58 μM. The competitive inhibitors of PTP1B (compounds 1 and 44) formed strong binding affinity, with catalytic active sites, proved by kinetic analysis, fluorescence spectra measurements, and computational simulations, and stimulated glucose uptake in the insulin-resistant HepG2 cells at the dose of 50 μM. In addition, FLC was rich in antioxidant and anti-inflammatory bioactive compounds so that they could be developed as nutraceuticals against diabetes.

Protective effects of four new saponins from Gynostemma pentaphyllum against hydrogen peroxide-induced neurotoxicity in SH-SY5Y cells

Gynostemma pentaphyllum has been used as a medicine-food homologious health product in China for a long time. This research aimed to isolate and identify its active compounds with protective effects against hydrogen peroxide induced SH-SY5Y cell death. Four new dammarane-type saponins were isolated from G. pentaphyllum using various chromatographic methods. They were identified as gypenoside S₁ (1), gypenoside S₃ (2), gypenoside S₂ (3) and gypenoside S₄ (4), respectively by HRESIMS and NMR spectra. Their cytotoxic activity was evaluated against three human cancer cell lines, A549 (lung), HepG2 (liver), SH-SY5Y (nerve), by MTT method. They showed low cytotoxicities with the IC₅₀ values of more than 100 μM on three cancer cell lines. However, they appeared protective effects against hydrogen peroxide induced SH-SY5Y cell death in a dose-dependent manner. They recovered cell viability more than 69% at the concentration of 20 μM from 66%, while as vitamin C to 67%. Compound 3 and 4 recovered more than 79% at 100 μM. The present study suggests that G. pentaphyllum has antioxidative potential and the saponins from G. pentaphyllum are considered as the active compounds with safe and neuroprotecitve effect.

ComMSnDB-An Automatable Strategy to Identify Compounds from MS Data Sets (Identification of Gypenosides as an Example)

Gynostemma pentaphyllum (Thunb.) Makino is a popular functional food and is also used as an important medicinal plant in China. Gypenoside, the main active constituent in G. pentaphyllum (Thunb.) Makino, belongs to dammarane-type triterpenoid saponins. Due to its high molecular weight and high polarity, it is difficult to obtain complete compound information for gypenoside extracts via mass spectrometry experiments. In this study, an automated targeted data postprocessing strategy called Compound MSⁿ Database (ComMSⁿDB) was designed and established to elucidate compounds in gypenoside extracts based on ultrahigh-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC-ESI-Q-TOF-MS/MS). As a result, 18 types of and 199 main saponin constituents, including 47 potential novel compounds, were tentatively identified from different habitats. At the same time, 15 gypenoside standard compounds were used to verify the feasibility of the ComMSⁿDB strategy. These results demonstrated that ComMSⁿDB offers practical value for quick, automated, and effective compound identification.

Dammarane-Type Saponins from Gynostemma pentaphyllum Prevent Hypoxia-Induced Neural Injury through Activation of ERK, Akt, and CREB Pathways

Gynostemma pentaphyllum possesses neuroprotective bioactivity. However, the effect of gypenosides on hypoxia-induced neural damage remains obscure. In this study, Gyp, the active fraction extracted from G. pentaphyllum and its bioactive compounds as well as the underlying molecular mechanisms were investigated. Eighteen dammarane-type saponins were isolated from Gyp. The absolute configurations of six unreported compounds (13-18) were assessed via electron capture detection (ECD) analyses. The results of cell viability assay showed that Gyp and its bioactive compounds (13-16 and 18) effectively protected PC12 cells from hypoxia injury. Gyp pretreatment also improved mice spatial memory impairment caused by hypoxia exposure. At the molecular level, Gyp and its bioactive compounds could activate the signaling pathways of ERK, Akt, and CREB in vitro and in vivo. In summary, Gyp and its bioactive compounds could prevent hypoxia-induced injury via ERK, Akt, and CREB signaling pathways.

Population genetic structure, migration, and polyploidy origin of a medicinal species Gynostemma pentaphyllum (Cucurbitaceae)

Gynostemma pentaphyllum, a member of family Cucurbitaceae, is a perennial creeping herb used as a traditional medicinal plant in China. In this study, six polymorphic nSSR and four EST-SSR primers were used to genotype 1,020 individuals in 72 wild populations of G. pentaphyllum. The genetic diversity and population structure were investigated, and ecological niche modeling was performed to reveal the evolution and demographic history of its natural populations. The results show that G. pentaphyllum has a low level of genetic diversity and high level of variation among populations because of pervasive asexual propagation, genetic drift, and long-term habitat isolation. Results of the Mantel test demonstrate that the genetic distance and geographic distance are significantly correlated among G. pentaphyllum natural populations. The populations can be divided into two clusters on the basis of genetic structure. Asymmetrical patterns of historical gene flow were observed among the clusters. For the contemporary, almost all the bidirectional gene flow of the related pairs was symmetrical with slight differences. Recent bottlenecks were experienced by 34.72% of the studied populations. The geographic range of G. pentaphyllum continues to expand northward and eastward from Hengduan Mountains. The present distribution of G. pentaphyllum is a consequence of its complex evolution. Polyploidy in G. pentaphyllum is inferred to be polygenetic. Finally, G. pentaphyllum is a species in need of protection, so in situ and ex situ measures should be considered in the future.

Profiling and activity screening of Dammarane-type triterpen saponins from Gynostemma pentaphyllum with glucose-dependent insulin secretory activity

The global prevalence of type 2 diabetes is increasing rapidly; consequently there is great need for new and novel therapeutic options. Gynostemma pentaphyllum (GP) is a traditional medicinal plant, mainly present in Southeast Asian countries, that has been reported to exert antidiabetic effects, by stimulating insulin secretion. The specific compound responsible for this effect is however as yet unidentified. Screening for discovery and identification of bioactive compounds of an herbal GP extract, was performed in isolated pancreatic islets from spontaneously diabetic Goto-Kakizaki (GK) rats, a model of type 2 diabetes, and from non-diabetic control Wistar rats. From this herbal extract 27 dammarane-type saponins, including two novel compounds, were isolated and their structure was elucidated by mass spectrometry and NMR spectroscopy. One of the dammarane-type triterpenoid showed a glucose-dependent insulin secretion activity. This compound, gylongiposide I, displays unique abilities to stimulate insulin release at high glucose levels (16.7 mM), but limited effects at a low glucose concentration (3.3 mM). Further studies on this compound, also in vivo, are warranted with the aim of developing a novel anti-diabetic therapeutic with glucose-dependent insulinogenic effect.

Two Nitrogen-containing Compounds from Pseudostellaria heterophylla

Two new nitrogen-containing compounds, pseudosteheterins A (1) and B (2), were isolated from the glycosides-enriched cardioprotective fraction of the 70% EtOH extract of the roots of Pseudostellaria heterophylla. Their structures were elucidated by spectroscopic methods, and the absolute configuration of 1 was established by quantum chemical TDDFT calculation of the ECD spectrum of its model compound. Pseudosteheterin B showed significant protective effects in H9c2 myocardial cells against CoCl2-induced injury.

Completion of Eight Gynostemma BL. (Cucurbitaceae) Chloroplast Genomes: Characterization, Comparative Analysis, and Phylogenetic Relationships

Gynostemma BL., belonging to the family Cucurbitaceae, is a genus containing 17 creeping herbaceous species mainly distributed in East Asia. It can be divided into two subgenera based on different fruit morphology. Herein, we report eight complete chloroplast genome sequences of the genus Gynostemma, which were obtained by Illumina paired-end sequencing, assembly, and annotation. The length of the eight complete cp genomes ranged from 157,576 bp (G. pentaphyllum) to 158,273 bp (G. laxiflorum). Each encoded 133 genes, including 87 protein-coding genes, 37 tRNA genes, eight rRNA genes, and one pseudogene. The four types of repeated sequences had been discovered and indicated that the repeated structure for species in the Subgen. Triostellum was greater than that for species in the Subgen. Gynostemma. The percentage of variation of the eight cp genomes in different regions were calculated, which demonstrated that the coding and inverted repeats regions were highly conserved. Phylogenetic analysis based on Bayesian inference and maximum likelihood methods strongly supported the phylogenetic position of the genus Gynostemma as a member of family Cucurbitaceae. The phylogenetic relationships among the eight species were clearly resolved using the complete cp genome sequences in this study. It will also provide potential molecular markers and candidate DNA barcodes for future studies and enrich the valuable complete cp genome resources of Cucurbitaceae.

Secondary Metabolite Production in Transgenic Hairy Root Cultures of Cucurbits

Cucurbits are important group of vegetables due to their nutritional significance and are also used for valuable traditional medicine. The infection of plants by Agrobacterium rhizogenes results in a hairy root (HR) phenotype characterized by rapid growth in hormone-free medium, an unusual ageotropism and extensive lateral branching. These genetically transformed root cultures (hairy roots) can produce levels of secondary metabolites comparable to that of intact plants. Hairy root cultures offer promise for high production and productivity of valuable secondary metabolites in many plants. High stability and productivity features allow the exploitation of HRs as valuable biotechnological tool for the production of plant secondary metabolites. While these chemical compounds are employed by plants for interactions with their environment, humans have long since explored and exploited plant secondary metabolites for medicinal and practical uses. The main constraint for commercial exploitation of hairy root cultivations is the development and scaling up of appropriate reactor vessels (bioreactors) that permit the growth of interconnected tissues normally unevenly distributed throughout the vessel. Emphasis has focused on designing appropriate bioreactors suitable to culture the delicate and sensitive plant hairy roots. To this end, hairy root culture presents an excellent platform for producing valuable secondary metabolites. For these reasons, this chapter describes the establishment of hairy roots and production of secondary metabolites from hairy roots of cucurbits and also phytochemicals uses for biological activity.

Characterization of Global Transcriptome Using Illumina Paired-End Sequencing and Development of EST-SSR Markers in Two Species of Gynostemma (Cucurbitaceae)

Gynostemma pentaphyllum is an important medicinal herb of the Cucurbitaceae family, but limited genomic data have hindered genetic studies. In this study, transcriptomes of two closely-related Gynostemma species, Gynostemma cardiospermum and G. pentaphyllum, were sequenced using Illumina paired-end sequencing technology. A total of 71,607 nonredundant unigenes were assembled. Of these unigenes, 60.45% (43,288) were annotated based on sequence similarity search with known proteins. A total of 11,059 unigenes were identified in the Kyoto Encyclopedia of Genes and Genomes Pathway (KEGG) database. A total of 3891 simple sequence repeats (SSRs) were detected in 3526 nonredundant unigenes, 2596 primer pairs were designed and 360 of them were randomly selected for validation. Of these, 268 primer pairs yielded clear products among six G. pentaphyllum samples. Thirty polymorphic SSR markers were used to test polymorphism and transferability in Gynostemma. Finally, 15 SSR makers that amplified in all 12 Gynostemma species were used to assess genetic diversity. Our results generated a comprehensive sequence resource for Gynostemma research.

Dammarane glycosides from the root of Machilus yaoshansis

Nine new dammarane triterpene glycosides (1-3 and 8-13) and 12 known analogues have been isolated from an ethanol extract of the roots of Machilus yaoshansis. Compounds 1-7 have an uncommon 20,23-dihydroxydammar-24-en-21-oic acid-21,23-lactone moiety that was previously reported in compounds isolated from Gynostemma pentaphyllum. The configurations of the lactone moieties in 1-3 were determined by comparison of the experimental ECD spectra of 1-3 and the hydrolysates, 1a and 1b, with the corresponding calculated ECD spectra. On the basis of NMR and ECD data analysis of 1-7, the previously reported C-20 and C-23 configurations of 4-7 and related derivatives from Gynostemma pentaphyllum were revised. In addition, the application of NMR data and Cotton effects to the determination of the relative and absolute configurations of the γ-lactone moiety in 3β,20,23-trihydroxydammar-24-en-21-oic acid-21,23-lactone derivatives is discussed.

Antimicrobial Materials Derived from the Endophytic Fungus Fusarium sp. of Eucommia ulmoides

Within our screening program for antimicrobial materials, eight compounds (1-8) were isolated from an endophytic fungus Fusarium sp. of Eucommia ulmoides. Compound 1, 2, 5-8 were isolated for the first time from endophytic fungi. Their structures were elucidated on the basis of NMR spectroscopic analysis with the reported data in the literature. All compounds showed potent antibacterial and antifungal activities and can be use as new antimicrobial materials.

Transcriptome profiling and insilico analysis of Gynostemma pentaphyllum using a next generation sequencer

Gynosaponins (Gypenosides) are major phyto-chemicals in Gynostemma pentaphyllum (Thunb.), with similarities to the ginsenosides present in Panax ginseng. Gynosaponins are classified as terpenoid compounds. In G. pentaphyllum, 25% of the total gynosaponins are similar to ginsenosides. In this study, we analyzed the transcriptional levels of the G. pentaphyllum genome to identify secondary metabolite genes. The complete transcriptomes for the roots and leaves were obtained using a GS-FLX pyro-sequencer. In total, we obtained 265,340 and all reads were well annotated according to biological databases. Using insilico analysis, 84% of sequence were well annotated and we obtained most of the secondary metabolite genes that represent mono-, di-, tri- and sesquiterpenoids. From our EST, most of the terpenoid genes were noted, among those few similar genes were studied in P. ginseng and these transcripts will help to characterize more triterpenoid genes in G. pentaphyllum. Also help to compare P. ginseng and G. pentaphyllum at transcriptome level.

Antineuroinflammatory constituents from the root extract of Paris verticillata

Two new cyclopropanoic fatty acid glycosides, named parisveroside A (1) and parisveroside B (2), were isolated from a MeOH extract of the roots of Paris verticillata (Liliaceae) together with three other known compounds, salicin (3), 3-(β-d-glucopyranosyloxymethyl)-2-(4-hydroxy-3-methoxyphenyl)-5-(3-hydroxypropyl)-7-methoxy-(2R,3S)-dihydrobenzofuran (4), and allantoin (5). Their structures were elucidated on the basis of spectroscopic data, including 1D and 2D NMR, HR-FAB-MS, and chemical evidence. To investigate the antineuroinflammatory effects of the isolated compounds (1–5), nitric oxide (NO) production was evaluated in the lipopolysaccharide-activated microglia cell line, BV-2. Compounds 2 and 4 significantly inhibited NO production with IC50 values of 74.8 and 60.5 µmol/L, respectively.

Chemical and DNA authentication of taste variants of Gynostemma pentaphyllum herbal tea

Gynostemma pentaphyllum Makino (Gp) was once used as a sweetener in Japan and is now widely consumed as an herbal tea worldwide for lowering cholesterol levels. Two taste variants, bitter and sweet, of Gp exist in the commercial market, but they cannot be differentiated morphologically nor by existing chemical analytical methods. This has been creating a problem in quality control of Gp products. In the present study, using HPLC-DAD and HPLC-ESI-MS analysis, we found that the Gp saponins, not flavonoids, from the sweet and bitter variants have distinctly different profiles. In addition, the two variants share only 69.01% homology in the ribosomal ITS-1 region, suggesting a phylogenic gap between these two variants. The combinations of chemical profiling and phylogenic analysis clearly confirm, for the first time, the distinction between these two taste variants. This information has direct application in the authentication and quality assessment of the various Gynostemma tea products.

Furostanol saponins from the rhizomes of Dioscorea japonica and their effects on NGF induction

The rhizome of Dioscorea japonica is a food and medicinal source known as 'San Yak' in Korea. Two new furostanol saponins, coreajaponins A (1) and B (2), together with 10 known compounds (3-12) were isolated from the rhizomes of D. japonica. Their structures were determined by spectroscopic methods, including 1D and 2D NMR techniques, HRMS, and chemical methods. Nerve growth factor (NGF), a crucial factor for neuronal survival and differentiation, can potentially improve neurodegenerative diseases and diabetic polyneuropathy. We evaluated the effects of isolates (1-12) on NGF induction in a C6 rat glioma cell line. Coreajaponin B (2) upregulated NGF content without significant cell toxicity, as did 6, 8, 9, and 11.

Dammarane-type saponins from Gynostemma pentaphyllum

Dammarane-type saponins, gypenosides VN1-VN7 (1-7), were isolated from the total saponin extract of Gynostemma pentaphyllum aerial parts, with their structures elucidated on the basis of spectroscopic and chemical methods. These compounds showed moderate cytotoxic activity against four human cancer cell lines, A549 (lung), HT-29 (colon), MCF-7 (breast), and SK-OV-3 (ovary), with IC(50) values ranging from 19.6+/-1.1 to 43.1+/-1.0 microM. Regarding the HL-60 (acute promyelocytic leukemia) cell line, compounds 1, 5, and 6 showed weakly active with IC(50) values of 62.8+/-1.9, 72.6+/-3.6, and 82.4+/-3.2 nM, respectively, while 2, 3, 4, and 7 were less active with IC(50) values>100 microM.

Dammarane-type glycosides and long chain sesquiterpene glycosides from Gynostemma yixingense

A new dammarane-type glycoside and a new long chain sesquiterpene glycoside, along with nine known compounds 20(S)-ginsenoside Rh1 (3), 20(R)-ginsenoside Rh1 (4), ginsenoside F1 (4), amarantholidoside IV (6), ginsenoside Rc (7), 20(S)-ginsenoside Rg2 (8), 20(R)-ginsenoside Rg2 (9), ginsenoside Rd (10) and gypenoside XLVI (11) were isolated from Gynostemma yixingense. The structures of the new compounds were determined on the basis of spectroscopic analysis, including 1D-, 2D-NMR and ESI-MS techniques as well as by comparison of the spectral data with those of related compounds as 2 alpha,3beta,20(S)-trihydroxydammar-24-ene-3-O-[beta-D-glucopyranosyl((1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-xylopyranosyl((1-->6)-beta-D-glucopyranoside] (1) (2E,6E)-10-beta-D-glucopyranosyl-1,10,11-trihydroxy-3,7,11-trimethyldodeca-2,6-diene (2).

Dammarane-type glycosides from Gynostemma pentaphyllum and their effects on IL-4-induced eotaxin expression in human bronchial epithelial cells

Two new dammarane-type glycosides, 2alpha,3beta,12beta,20S-tetrahydroxydammar-24-ene-3-O-[beta-d-glucopyranosyl(1-->4)-beta-d-glucopyranosyl]-20-O-[beta-d-xylopyranosyl-(1-->6)-beta-d-glucopyranoside] (1) and 2alpha,3beta,12beta,20S-tetrahydroxydammar-24-ene-3-O-beta-d-glucopyranosyl-20-O-[beta-d-6-O-acetylglucopyranosyl-(1-->2)-beta-d-glucopyranoside] (2), were isolated from a MeOH extract of the leaves of Gynostemma pentaphyllum. Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The isolated compounds showed potential inhibitory effects on eotaxin expression in BEAS-2B bronchial epithelial cells.

Dammarane-type triterpene saponins from the flowers of Panax notoginseng

Four new dammarane-type triterpene saponins named floranotoginsenosides A (1), B (2), C (3) and D (4), together with five known triterpene saponins, were isolated from the flowers of Panax notoginseng. Their structures were elucidated on the basis of spectral and chemical evidence.

Gynostemma pentaphyllum decreases allergic reactions in a murine asthmatic model

The increasing incidence of asthma in developing countries emphasizes the importance of identifying more effective treatments that have low cost. Gynostemma pentaphyllum (Thunb.) Makino (Cucurbitaceae), a common herbal tea in China, has been used to treat lung inflammation. Since the Th2 cytokines are the major mediators in the pathogenesis of asthma, Th1-biased immune responses caused by G. pentaphyllum might have the potential to relieve asthmatic symptoms. We hypothesized that oral administration of G. pentaphyllum extracts might suppress Th2 cytokine-induced airway inflammation responses in ovalbumin (OVA)-sensitive mice. BALB/c mice were sensitized with intraperitoneal injection and challenged 3 times with OVA inhalation (IH) (the IH3 model). G. pentaphyllum was orally administered for 7 consecutive days before the end of the OVA challenge. In the IH5 model, 2 more OVA challenges were administered to mimic the encounter with an allergen after drug treatment. G. pentaphyllum extracts significantly attenuated airway hyperresponsiveness (AHR) and inhibited eosinophil infiltration in mice in both models. Serum OVA-specific antibodies were also reduced with the treatment. Decreased Th2-type cytokines and increased IFN-gamma were detected in the cultures of OVA-activated splenocytes from treated mice. Our results suggest that G. pentaphyllum extracts might be beneficial for asthma airway inflammation through the suppression of Th2 activity.

Structure elucidation and complete NMR spectral assignments of two new dammarane-type tetraglycosides from Panax quinquefolium

Two new saponins were isolated from leaves of Panax quinquefolium and their structures were elucidated as 3beta, 12beta, 20S-trihydroxy-25-methoxydammar-23-ene 3-O-{[beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-20-O-[alpha-L-arabinopyranosyl(1-->6)]-beta-D-glucopyranoside (1) and 3beta, 20S-dihydroxy-12beta, 23R-epoxydammar-24-ene 3-O-{[beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-xylopyanosyl(1-->6)]-beta-D-glucopyranoside (2) on the basis of (1)D and (2)D NMR (including (1)H, (13)C-NMR, (1)H-(1)H COSY, HSQC, TOCSY, HMBC, and NOESY), ESI-MS spectrometry and chemical methods.

Dammarane-type glycosides from Gynostemma pubescens

Triterpene saponins 1-8 were isolated from the aerial parts of Gynostemma pubescens. Among them, compounds 1-4, 8 possess carboxylic groups at both C-21 and C-29, 5 contains a carboxylic group at C-21 and an aldehyde function at C-29, whereas 6 and 7 contain carboxylic groups at C-21 and hydroxymethylene groups at C-29. Their structural elucidation was accomplished by extensive spectroscopic methods including application of 1D (1H, (13)C, (13)C DEPT) and 2D NMR experiments (HMQC, HMBC, HSQC), HRESIMS analysis, as well as by chemical degradation.

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.

Nine new dammarane saponins from Gynostemma pentaphyllum

Nine new dammarane saponins, 1-9, were isolated from the MeOH extract of the aerial part of Gynostemma pentaphyllum, an edible plant of the Cucurbitaceae family, that grows wildly in China. Their structures were elucidated by 1D- and 2D-NMR analysis, as well as by chemical degradation. Aglycons 21,24-cyclopentyldammar-25-ene of 6 and 7, and 21,24-cyclopentyldammarane of 8 and 9, were novel. Compounds 1, 4, and 8 showed moderate antitumor activities against stomach cancer cells SGC-7901 and liver cancer cells BEL-7402.

Hairy root cultures of Gynostemma pentaphyllum (Thunb.) Makino: a promising approach for the production of gypenosides as an alternative of ginseng saponins

Hairy root cultures of Gynostemma pentaphyllum were established by infecting leaf discs with Agrobacterium rhizogenes. The dry biomass of hairy roots grown in MS medium for 49 days was 7.3 g l(-1) with a gypenoside content of 38 mg g(-1) dry wt.