Characterization of steroidal saponins in crude extract from Dioscorea nipponica Makino by liquid chromatography tandem multi-stage mass spectrometry

Protective effects of methyl protodioscin against lipid disorders and liver injury in hyperlipidemic gerbils

Methyl protodioscin (MPD) is the main component of total diosgenin, which was reported to reduce cholesterol and triglyceride levels potentially. This study aimed to investigate the beneficial effects of MPD against lipid disorder in hyperlipidemic gerbils induced by a high-fat diet (HFD). Hyperlipidemia was induced in gerbils by feeding them with HFD for six weeks, and a daily oral dose of MPD solution (25 and 50 mg/kg/day) was administered. This study investigated blood lipid levels and hepatic lipid accumulation in hyperlipidemic gerbils. The potential mechanism of MPD was explored by detecting the expression level of genes, including SREBPs, ACC, FASN, HMGCR, PCSK9, and LDL-R. The results showed that MPD treatment decreased the body weight, the relative weight of the liver, blood lipid, and hepatic lipid levels of gerbils fed with HFD. The administration of MPD alleviates liver steatosis and injury in gerbils fed with an HFD. MPD treatment reduced the expression of HMGCR, increased the expression of LDL-R, and decreased the expression of PCSK9 for cholesterol reduction. Additionally, MPD treatment reduced the expression of hepatic ACC and FASN for triglycerides reduction. The underlying mechanisms for these effects are attributed to MPD-induced inhibition of protein expression of LXR, SREBP1, and SREBP2. This study demonstrates that MPD protects gerbils against lipid disorders and liver injury by suppressing hepatic SREBPs expression.

Mass spectrometry analysis of saponins

Saponins are amphiphilic molecules of pharmaceutical interest and most of their biological activities (i.e., cytotoxic, hemolytic, fungicide, etc.) are associated to their membranolytic properties. These molecules are secondary metabolites present in numerous plants and in some marine animals, such as sea cucumbers and starfishes. Structurally, all saponins correspond to the combination of a hydrophilic glycan, consisting of sugar chain(s), linked to a hydrophobic triterpenoidic or steroidic aglycone, named the sapogenin. Saponins present a high structural diversity and their structural characterization remains extremely challenging. Ideally, saponin structures are best established using nuclear magnetic resonance experiments conducted on isolated molecules. However, the extreme structural diversity of saponins makes them challenging from a structural analysis point of view since, most of the time, saponin extracts consist in a huge number of congeners presenting only subtle structural differences. In the present review, we wish to offer an overview of the literature related to the development of mass spectrometry for the study of saponins. This review will demonstrate that most of the past and current mass spectrometry methods, including electron, electrospray and matrix-assisted laser desorption/ionization ionizations, gas/liquid chromatography coupled to (tandem) mass spectrometry, collision-induced dissociation including MS³ experiments, multiple reaction monitoring based quantification, ion mobility experiments, and so forth, have been used for saponin investigations with great success on enriched extracts but also directly on tissues using imaging methods.

Advances in the Biosynthesis and Molecular Evolution of Steroidal Saponins in Plants

Steroidal saponins are an important type of plant-specific metabolite that are essential for plants' responses to biotic and abiotic stresses. Because of their extensive pharmacological activities, steroidal saponins are also important industrial raw materials for the production of steroidal drugs. In recent years, more and more studies have explored the biosynthesis of steroidal saponins in plants, but most of them only focused on the biosynthesis of their molecular skeleton, diosgenin, and their subsequent glycosylation modification mechanism needs to be further studied. In addition, the biosynthetic regulation mechanism of steroidal saponins, their distribution pattern, and their molecular evolution in plants remain unclear. In this review, we summarized and discussed recent studies on the biosynthesis, molecular regulation, and function of steroidal saponins. Finally, we also reviewed the distribution and molecular evolution of steroidal saponins in plants. The elucidation of the biosynthesis, regulation, and molecular evolutionary mechanisms of steroidal saponins is crucial to provide new insights and references for studying their distribution, diversity, and evolutionary history in plants. Furthermore, a deeper understanding of steroidal saponin biosynthesis will contribute to their industrial production and pharmacological applications.

Strategy of combining offline 2D LC-MS with LC-DIA-MS/MS to accurately identify chemical compounds and for quality control of Dioscorea septemloba Thunb

INTRODUCTION

Dioscorea septemloba Thunb. (DST), the rhizome of Dioscorea spongiosa J. Q. Xi, M. Mizuno et W. L. Zhao or Fuzhou Dioscorea futschauensis Uline ex R. Kunth, has multiple biological activities.

OBJECTIVES

We aimed to comprehensively characterize the chemical composition of DST and develop a quality control method.

METHODS

Based on a UHPLC/Q-Orbitrap-MS platform, we developed an offline 2D LC-MS method (HILIC×RPLC) to characterize the chemical constituents in the 75% ethanol extract of DST at first. Secondly, a data-independent acquisition mode (DIA) was further established to conduct rapid qualitative analysis of compounds in DST from different habitats. Then, six differential compounds were screened out and selected as quantitative markers by UPLC-QQQ-MS to evaluate the content of DST from different habitats.

RESULTS

In total, 137 compounds were identified in DST by combining offline 2D LC-MS with LC-DIA-MS/MS. Then, simultaneous targeted/non-targeted scanning technology was established based on the precursor ion list. Finally, six compounds, including dioscin, gracillin, pseduoprotodioscin, pseudoprotogracillin, protodioscin, and protogracillin, were accurately determined. The method validation showed a good linear relationship in the concentration range investigated (R² > 0.999). The average recovery ranged from 86% to 107.5%, and LOD and LOQ were between 0.01 and 0.40 μg·mL^-1 .

CONCLUSION

Our strategy integrating offline 2D LC-MS and the DIA mode could effectively separate and identify compounds from DST, indicating it can be used in subsequent compounds characterization studies. At the same time, the quality of DST was comprehensively and systematically evaluated.

Dioscorea nipponica Makino Rhizome Extract and Its Active Compound Dioscin Protect against Neuroinflammation and Scopolamine-Induced Memory Deficits

Activation of microglial cells by intrinsic or extrinsic insult causes neuroinflammation, a common phenomenon in neurodegenerative diseases. Prevention of neuroinflammation may ameliorate many neurodegenerative disease progressions. Dioscorea nipponica Makino (DN) extract can alleviate muscular atrophy and inflammatory diseases; however, the efficacy and mechanism of action in microglial cells remain unknown. The current study investigates the possible anti-inflammatory effects and mechanisms of Dioscorea nipponica Makino ethanol extract and its steroidal saponin dioscin. Our in vitro study shows that Dioscorea nipponica rhizome ethanol extract (DNRE) and dioscin protect against lipopolysaccharide (LPS)-activated inflammatory responses in BV-2 microglial cells by inhibiting phosphorylation and the nuclear translocation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), resulting in the downregulation of pro-inflammatory cytokines and enzymes. Consistent with our previous report of dioscin-mediated enhancement of neurotrophic factors in dopaminergic cells, here we found that dioscin upregulates brain-derived neurotrophic factor (BDNF) and cAMP-response element binding protein (CREB) phosphorylation (pCREB) in the cerebral cortex and hippocampus regions of the mouse brain. Scopolamine treatment increased pro-inflammatory enzyme levels and reduced the expression of BDNF and pCREB in the hippocampus and cortex regions, which led to impaired learning and referencing memory in mice. Pre-treatment of dioscin for 7 days substantially enhanced mice performances in maze studies, indicating amelioration in cognitive deficits. In conclusion, DNRE and its active compound dioscin protect against neurotoxicity most likely by suppressing NF-κB phosphorylation and upregulating neurotrophic factor BDNF.

Diosgenin From Dioscorea Nipponica Rhizoma Against Graves’ Disease—On Network Pharmacology and Experimental Evaluation

Dioscorea nipponica rhizoma (DNR) is commonly used for the cure of hyperthyroidism resulting from Graves’ disease (GD) or thyroid nodules. However, its therapeutic mechanism remains unclear. This study aimed to utilize network pharmacology integrated molecular docking and experimental verification to reveal the potential pharmacological mechanism of DNR against GD. First, the active componds of DNR were collected from the HERB database and a literature search was conducted. Then, according to multisource database, the predicted genes of DNR and GD were collected to generate networks. The analysis of protein–protein interaction and GO enrichment and KEGG pathway were employed to discover main mechanisms associated with therapeutic targets. Moreover, molecular docking simulation was applied in order to verify the interactions between the drug and target. Finally, our experiments validated the ameliorated effects of diosgenin, the main component of DNR, in terms of phosphorylation deactivation in IGF-1R, which in turn inhibited the phosphorylation and activation of PI3K-AKT and Rap1-MEK signaling pathways, promoting cell apoptosis and GD remission. Our present study provided a foundation for further investigation of the in-depth mechanisms of diosgenin in GD and will provide new scientific evidence for clinical application.

The genome of Dioscorea zingiberensis sheds light on the biosynthesis, origin and evolution of the medicinally important diosgenin saponins

Diosgenin saponins isolated from Dioscorea species such as D. zingiberensis exhibit a broad spectrum of pharmacological activities. Diosgenin, the aglycone of diosgenin saponins, is an important starting material for the production of steroidal drugs. However, how plants produce diosgenin saponins and the origin and evolution of the diosgenin saponin biosynthetic pathway remain a mystery. Here we report a high-quality, 629-Mb genome of D. zingiberensis anchored on 10 chromosomes with 30 322 protein-coding genes. We reveal that diosgenin is synthesized in leaves ('source'), then converted into diosgenin saponins, and finally transported to rhizomes ('sink') for storage in plants. By evaluating the distribution and evolutionary patterns of diosgenin saponins in Dioscorea species, we find that diosgenin saponin-containing may be an ancestral trait in Dioscorea and is selectively retained. The results of comparative genomic analysis indicate that tandem duplication coupled with a whole-genome duplication event provided key evolutionary resources for the diosgenin saponin biosynthetic pathway in the D. zingiberensis genome. Furthermore, comparative transcriptome and metabolite analysis among 13 Dioscorea species suggests that specific gene expression patterns of pathway genes promote the differential evolution of the diosgenin saponin biosynthetic pathway in Dioscorea species. Our study provides important insights and valuable resources for further understanding the biosynthesis, evolution, and utilization of plant specialized metabolites such as diosgenin saponins.

High-throughput serum metabolomics analysis of gouty arthritis rat treated by total saponins of Rhizoma Dioscoreae Makino by UPLC-Q/TOF-MS

Rhizoma Dioscoreae Makino (RDM) is effective in treating gouty arthritis (GA) and hyperuricacidemia, especially in promoting uric acid excretion and reducing the inflammatory reaction. Bioactive constituents in RDM are mainly steroidal saponins such as dioscin, trillin, protodioscin and protogracillin. However, the mechanism of its anti-GA action is still unclear, owing to the complex pathological and physiological characteristics of GA, and integration of RDM with multiple components, multiple targets and multiple pathways. Herein, a GA rat model was induced with monosodium urate (MSU), and RDM reduced inflammation of rat synovium tissue. Through metabolomics analysis, 35 potential biomarkers with significant changes involved in the pathogenesis of GA induced by MSU were identified, and perturbations were restored after RDM treatment. The most correlated pathways involved in d-galactose, d-mannose, d-glucose, myoinositol, Phosphatidylcholine (PC) (16:0/16:0), LysoPC (15:0), phosphatidic acid (PA) [18:1(9Z)/18:1(11Z)] and glutathione induced by MSU were galactose metabolism, inositol phosphate metabolism, glycerophospholipid metabolism and glutathione metabolism, and the derivations of all those biomarkers could be regulated by RDM treatment. RDM has a therapeutic effect on GA by intervening in changes in endogenous metabolisms and the related metabolic pathways.

Lithium ion adduction enables UPLC-MS/MS-based analysis of multi-class 3-hydroxyl group-containing keto-steroids

Steroids that contain a 3-hydroxyl group (3-OH steroids) are widely distributed in nature. During analysis with ESI-MS, they easily become dehydrated while in the protonated form, resulting in the production of several precursor ions and leading to low sensitivity of detection. To address this analytical challenge, here, we developed a method for the quantitation of 3-OH steroids by LC-MS/MS coupled with post-column addition of lithium (Li) ions to the mobile phase. The Li ion has a high affinity for the keto group of steroids, stabilizing their structures during ionization and permitting detection of analytes exclusively as the lithiated form. This not only improved the intensities of the precursor ions, but also promoted the formation of typical lithiated fragment ions. This improvement made the quantitation by multiple reaction monitoring more sensitive and reliable, as evidenced by 1.53-188 times enhanced detection sensitivity of 13 steroids that contained at least one keto and two hydroxyl groups or one keto and one 5-olefinic double bond, among 16 different 3-OH steroids. We deployed our newly developed method for profiling steroids in mouse brain tissue and identified six steroids in one tissue sample. Among these, 16-hydroxyestrone, tetrahydrocorticosterone, and 17α-hydroxypregnenolone were detected for the first time in the mouse brain. In summary, the method described here enables the detection of lithiated steroids by LC-MS/MS, including three 3-OH steroids not previously reported in the mouse brain. We anticipate that this new method may allow the determination of 3-OH steroids in different brain regions.

Estrogenic and anti-inflammatory effects of pseudoprotodioscin in atherosclerosis-prone mice: Insights into endothelial cells and perivascular adipose tissues

Pseudoprotodioscin (PPD), a phytoestrogen isolated from Dioscorea nipponica Makino, is recognized to possess anti-inflammatory and antiadipogenic capacities. However, little is known about the antiatherosclerotic effects of PPD and the underlying mechanisms. Here, the contribution of estrogen receptors (ERs) and inflammation to PPD-mediated amelioration of endothelial dysfunction has been fully assessed. PPD administration alleviated atherosclerotic lesions by lowering total cholesterol in ovariectomized apoE^-/- mice fed a high-cholesterol diet. Molecular docking analysis suggested a selective interaction of PPD with ERα. Upon PPD treatment, ERα and endothelial nitric oxide synthase (eNOS) protein levels were increased, whereas cell adhesion molecule and monocyte chemoattractant protein-1 (MCP-1) mRNA levels were suppressed in human umbilical vein endothelial cells (HUVECs) after injury caused by oxidized low-density lipoprotein (ox-LDL). These effects could be abolished by an ERα antagonist or a NOS inhibitor. Whereas, PPD can ERα-independently suppress TNFα expression in peritoneal macrophages upon LPS induction. Estrogen deficiency induced inflammatory phenotypes in perivascular adipose tissue (PAT), which could be partially attenuated by PPD. The increased release of adiponectin in PAT after PPD treatment is in accordance with previous reported data showing that adiponectin exerts anti-inflammatory effects in multiple cell types. ERα-dependent antiadipogenic effects of PPD were also detected in PAT-derived stromal cells. The present study reveals a novel mechanism through which PPD exerts estrogenic and anti-inflammatory properties in atherosclerosis-prone mice. Thus, PPD is a promising compound which has potential therapeutic effects on atherosclerotic cardiovascular diseases in postmenopausal women.

Development of an Oriental Medicine Discrimination Method through Analysis of Steroidal Saponins in Dioscorea nipponica Makino and Their Anti-Osteosarcoma Effects

To prevent confusing Dioscorea nipponica (DN), an Oriental medicine, with Dioscorea quinquelobata (DQ) and Dioscorea septemloba (DS), a simple and accurate quantitative analysis method using HPLC combined with ultraviolet (UV) detection was developed and verified with UPLC-QTOF/MS through identification of five saponin glycosides: protodioscin (1), protogracillin (2), pseudoprotodioscin (3), dioscin (4), and gracillin (5). The newly developed analysis method showed sufficient reproducibility (<1.91%) and accuracy (92.1%–102.6%) and was able to identify DN based on the presence of compound 3 (13.821 ± 0.037 mg/mL) and the absence of 5. Compound 1, which is present in DN at a relatively high level (159.983 ± 0.064 mg/mL), was also an important marker for identification. Among the three species, DN showed the strongest activation of apoptotic signaling in osteosarcoma cells, while the four compounds detected in DN showed IC₅₀ values of 6.43 (1), 10.61 (2), 10.48 (3), and 6.90 (4). In conclusion, the strong inhibitory effect of DN against osteosarcoma was confirmed to be associated with 1 and 4, which is also related to the quantitative results. Therefore, the results of this study might provide important information for quality control related to Oriental medicine.

Inhibition of tumor metastasis by targeted daunorubicin and dioscin codelivery liposomes modified with PFV for the treatment of non-small-cell lung cancer

Background: Chemotherapy for non-small-cell lung cancer (NSCLC) still leads to unsatisfactory clinical prognosis because of poor active targeting and tumor metastasis. Purpose: The objective of this study was to construct a kind of PFV peptide modified targeted daunorubicin and dioscin codelivery liposomes, which could enhance tumor targeting and inhibit tumor cell metastasis. Methods and results: Targeted daunorubicin and dioscin codelivery liposomes were prepared by film dispersion and the ammonium sulfate gradient method. With the ideal physicochemical properties, targeted daunorubicin and dioscin codelivery liposomes exhibited enhanced cellular uptake and showed strong cytotoxicity to tumor cells. The encapsulation of dioscin increased the inhibitory effects of daunorubicin on A549 cells, vasculogenic mimicry (VM) channels and tumor metastasis. The enhanced antimetastatic mechanism of the targeted liposomes was attributed to the downregulation of matrix metalloproteinase-2 (MMP-2), vascular endothelial cadherin (VE-Cad), transforming growth factor-β1 (TGF-β1) and hypoxia inducible factor-1α (HIF-1α). Meanwhile, the targeted daunorubicin and dioscin codelivery liposomes exhibited significant antitumor effects in tumor-bearing mice. H&E staining, immunohistochemistry with Ki-67 and TUNEL assay also showed the promoted antitumor activity of the targeted liposomes. Conclusion: Targeted daunorubicin and dioscin codelivery liposomes may provide an effective strategy for the treatment of NSCLC.

High Resolution Mass Profile of Bufadienolides and Peptides Combing with Anti-Tumor Cell Screening and Multivariate Analysis for the Quality Evaluation of Bufonis Venenum

In order to evaluate the quality of Bufonis Venenum commercial herbs, a three-step qualitative and quantitative research study was performed. Firstly, we tried to identify small molecules and peptides in Bufonis Venenum using pre-fractionation chromatography and high-resolution mass spectrometry. The database search of the small molecules and peptides of Bufonis Venenum revealed that the dried venom consisted of free/conjugated-type bufadienolides and peptides with a mass range of 0.4–2 kDa. Secondly, we used partial least squares (PLS) multivariate statistical analysis to screen bufadienolides markers (VIP > 1.5) responsible for the anti-tumor cell activity of Bufonis Venenum, including 21 identified bufadienolides and 7 unknown compounds. It is noticeable that these bufadienolide markers could not be recognized by traditional HPLC-UV based spectrum-effect relationship analysis (correlation coefficient ranging from −0.24 to 0.40). Finally, we proposed a weight coefficient-based corrected total contents of 9 bufadienolides as a quality evaluation indicator, which had good correlation with inhibitory effects on tumor cells of commercial Bufonis Venenum. The correlation coefficient increased from 0.4 to 0.6. Thus, our pre-fractionation chromatography and mass spectrometry strategy had significant advancement over the traditional spectrum–effect relationship method for chemical marker identification. These results could be crucial and helpful in the development of a quality evaluation method that could reflect the pharmacological activity of Bufonis Venenum.

Recent advances in steroidal saponins biosynthesis and in vitro production

Steroidal saponins exhibited numerous pharmacological activities due to the modification of their backbone by different cytochrome P450s (P450) and UDP glycosyltransferases (UGTs). Plant-derived steroidal saponins are not sufficient for utilizing them for commercial purpose so in vitro production of saponin by tissue culture, root culture, embryo culture, etc, is necessary for its large-scale production. Saponin glycosides are the important class of plant secondary metabolites, which consists of either steroidal or terpenoidal backbone. Due to the existence of a wide range of medicinal properties, saponin glycosides are pharmacologically very important. This review is focused on important medicinal properties of steroidal saponin, its occurrence, and biosynthesis. In addition to this, some recently identified plants containing steroidal saponins in different parts were summarized. The high throughput transcriptome sequencing approach elaborates our understanding related to the secondary metabolic pathway and its regulation even in the absence of adequate genomic information of non-model plants. The aim of this review is to encapsulate the information related to applications of steroidal saponin and its biosynthetic enzymes specially P450s and UGTs that are involved at later stage modifications of saponin backbone. Lastly, we discussed the in vitro production of steroidal saponin as the plant-based production of saponin is time-consuming and yield a limited amount of saponins. A large amount of plant material has been used to increase the production of steroidal saponin by employing in vitro culture technique, which has received a lot of attention in past two decades and provides a way to conserve medicinal plants as well as to escape them for being endangered.

Dioscorea nipponica Makino: a systematic review on its ethnobotany, phytochemical and pharmacological profiles

Dioscorea nipponica Makino is a perennial twining herbs belonging to the family Dioscoreaceae, which is mainly distributed in the northeastern, northern, eastern and central regions of China. Traditionally, the rhizome of this herb has been commonly used by Miao and Meng ethnic groups of China to treat rheumatoid arthritis, pain in the legs and lumbar area, Kashin Beck disease, bruises, sprains, chronic bronchitis, cough and asthma. Modern pharmacological studies have discovered that this herb possesses anti-tumor, anti-inflammatory, anti-diuretic, analgesic, anti-tussive, panting-calming and phlegm-dispelling activities, along with enhancing immune function and improving cardiovascular health. In recent years, both fat-soluble and water-soluble steroidal saponins were isolated from the rhizomes of D. nipponica using silica gel column chromatography, thin layer chromatography and high performance liquid chromatography methods. Saponin and sapogenins are mainly responsible for most of the pharmacological effects of this plant. Further, the chemical components of the aboveground parts contain more than 10 kinds of phenanthrene derivatives. The present review summarizes the knowledge concerning the geographical distribution, chemical composition, pharmacological effects, toxicology studies and clinical applications of D. nipponica.

Combined Application of UHPLC-QTOF/MS, HPLC-ELSD and 1 H-NMR Spectroscopy for Quality Assessment of DA-9801, A Standardised Dioscorea Extract

INTRODUCTION

DA-9801, a standardised 50% aqueous ethanolic extract of a mixture of Dioscorea japonica and D. nipponica, is a botanical drug candidate for the treatment of diabetic neuropathy, which finished its US phase II clinical trials recently. An advanced quality control method is needed for further development of DA-9801, considering its high contents of both primary and secondary metabolites.

OBJECTIVE

Development of a quality assessment strategy for DA-9801, based on the combination of UHPLC-QTOF/MS, HPLC-ELSD, and ¹ H-NMR spectroscopy.

METHODS

The method was developed and tested with 15 batch products of DA-9801. The steroidal saponins of DA-9801 were tentatively identified by UHPLC-QTOF/MS and were quantified with the validated HPLC-ELSD method. Primary metabolites of DA-9801 were identified and profiled using ¹ H-NMR spectrometry. The batch-to-batch equivalence of DA-9801 was tested with the ¹ H-NMR spectra using spectral binning, correlation analysis, and principal component analysis.

RESULTS

Six major saponins of DA-9801 were tentatively identified by UHPLC-QTOF/MS. Among them, protodioscin and dioscin were quantified by the validated HPLC-ELSD method. Twenty-six metabolites were identified in ¹ H-NMR spectra. The similarity between DA-9801 batches could be evaluated with the NMR spectra of DA-9801. The ¹ H-NMR method also revealed that two Dioscorea species contributed distinct amino acids to the contents of DA-9801.

CONCLUSION

This study validates the effectiveness of UHPLC-QTOF/MS, HPLC-ELSD, and ¹ H NMR-combined method for quality control of DA-9801 and its crude materials. Copyright © 2016 John Wiley & Sons, Ltd.

Determination of pseudoprotodioscin in rat plasma by UPLC-MS/MS: Assay development and application to pharmacokinetic study

An original and sensitive ultraperformance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method for the determination of pseudoprotodioscin (PPD) in rat plasma was developed and validated. Digitoxin was applied as an internal standard. Plasma samples were processed by acetonitrile-mediated plasma protein precipitation and chromatographed using a step gradient program on a C18 column (2.1×50mm i.d., 1.7μm). The mobile phase was comprised of acetonitrile and 0.1mmolL(-1) aqueous lithium acetate mixed with 0.03% formic acid at the flow rate of 0.2mLmin(-1). Multiple reaction monitoring (MRM) transitions were performed for detection and lithium adduct ions were employed with a significant improvement of the response of the analytes in electrospray positive ionization mode. The concentration range of calibration curve was linear over the range 2-5000ngmL(-1). The intra- and inter-day precisions were all less than 11.5% and accuracies were within the range of 94.1-103.5%, and the analytes exhibited no severe matrix effect. The validated method was successfully applied in the pharmacokinetics of PPD after intragastric (50mgkg(-1)) and intravenous (4mgkg(-1)) administration in rats. PPD showed rapid excretion and with bioavailability of simply about 5.7% in rats.

Dioscorea nipponica Attenuates Migration and Invasion by Inhibition of Urokinase-Type Plasminogen Activator through Involving PI3K/Akt and Transcriptional Inhibition of NF-κB and SP-1 in Hepatocellular Carcinoma

High mortality and morbidity rates for hepatocellular carcinoma (HCC) in Taiwan primarily result from uncontrolled tumor metastasis. In our previous studies, we have reported that Dioscorea nipponica Makino extract (DNE) has anti-metastasis effects on human oral cancer cells. However, the effect of DNE on hepatoma metastasis have not been thoroughly investigated and remains poorly understood. To determine the effects of DNE on the migration and invasion in HCC cells we used a wound healing model, Boyden chamber assays, gelatin/casein zymography and Western blotting. Transcriptional levels of matrix metalloproteinase-9 (MMP-9) and urokinase-type plasminogen activator (u-PA) were detected by real-time PCR and promoter assays. In this study, DNE treatment significantly inhibited the migration/invasion capacities of Huh7 cell lines. The results of gelatin/casein zymography and Western blotting revealed that the activities and protein levels of the MMP-9 and u-PA were inhibited by DNE. Tests of the mRNA levels, real-time PCR, and promoter assays evaluated the inhibitory effects of DNE on u-PA expression in human hepatoma cells. A chromatin immunoprecipitation (ChIP) assay showed not only that DNE inhibits u-PA expression, but also the inhibitory effects were associated with the down-regulation of the transcription factors of NF-[Formula: see text]B and SP-1 signaling pathways. Western blot analysis also showed that DNE inhibits PI3K and phosphorylation of Akt. In conclusion, these results show that u-PA expression may be a potent therapeutic target in the DNE-mediated suppression of HCC invasion/migration. DNE may have potential use as a chemo-preventive agent against liver cancer metastasis.

Diagnostic ion filtering strategy for chemical characterization of Guge Fengtong Tablet with high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

The present study was designed to characterize the chemical constituents of Guge Fengtong Tablet (GGFTT). Based on the chromatographic retention behavior, fragmentation pathways of chemical components and the published literatures, a diagnostic ion filtering strategy with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-Q-TOF/MS) was established to identify the multiple bioactive constituents of GGFTT. The rapid identification of forty-seven components, including 18 phenolic acids, 8 saponins, 14 gingerol-related compounds, and 7 diarylhepatonoids, was accomplished using this newly developed method. The coupling of HPLC-ESI-Q-TOF/MS with the diagnostic ion filtering strategy was useful and efficient for the in-depth structural elucidation of chemical compounds of GGFTT.

Determination of the chemical constituents of the different processed products of Anemarrhena asphodeloides Rhizomes by high-performance liquid chromatography quadrupole time-of-flight mass spectrometry

In this work, high-performance liquid chromatography (HPLC) coupled with a hybrid quadrupole time of-flight mass spectrometry (Q-TOF-MS/MS) was used to study chemical compositions of different processed products of Rhizoma Anemarrhenae (RA). A Grace Alltima(TM) C18 column (250 × 4.6 mm, 5 µm) was used for separation. Mobile phase consisted of 0.1% formic acid and acetonitrile, using gradient elution. ESI-MS data was acquired in both positive and negative mode. The experiment was established on the basis of a series of reference substances (two xanthone and seven saponins) to qualitatively identify the chemical compounds of different processed products of RA by MS analysis. There was no difference in the type of chemical constituents between different processed products of RA. A total of 25 compounds were identified, including four xanthones, 21 steroidal saponins and eight pairs of isomers.

Comparative analysis of steroidal saponins in four Dioscoreae herbs by high performance liquid chromatography coupled with mass spectrometry

Steroidal saponins, which exhibit multiple pharmacological effects, are the major bioactive constituents in herbal medicines from Dioscoreae species. In this study, a sensitive method based on high performance liquid chromatography-mass spectrometry (HPLC-MS) was established and validated for qualitative and quantitative analysis of steroidal saponins in four Dioscoreae herbs including Dioscoreae Nipponica Rhizome (DNR) and Dioscoreae Hypoglaucae Rhizome (DHR), Dioscoreae Spongiosae Rhizome (DSR) and Dioscoreae Rhizome (DR). A total of eleven steroidal saponins were identified by high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-QTOF/MS). Furthermore, seven major steroidal saponins was simultaneous quantified using a high performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC-QQQ/MS). The qualitative and quantitative analysis results indicated that the chemical composition of DNR, DHR and DSR samples exhibited a high level of global similarity, while the ingredients in DR varied greatly from the other three herbs. Moreover, principal component analysis (PCA) and hierarchical clustering analysis (HCA) were performed to compare and discriminate the Dioscoreae herbs based on the quantitative data. The results demonstrated the qualitative and quantitative analysis of steroidal saponins based on HPLC-MS is a feasible method for quality control of Dioscoreae herbs.

Development and validation of liquid chromatography-tandem mass spectrometry method for simultaneous determination of six steroidal saponins in rat plasma and its application to a pharmacokinetics study

A specific and reliable liquid chromatography-electrospray ionization-tandem mass spectrometry method was developed for the simultaneous determination of timosaponin H1 (TH1), timosaponin E1 (TE1), timosaponin E (TE), timosaponin B-II (TB-II), timosaponin B-III (TB-III) and anemarrhenasaponin I (AS-I) in rat plasma. After addition of internal standard (IS) ginsenoside Rh1, plasma samples were pretreated by protein precipitation with acetonitrile. Chromatographic separation was performed on a reverse phase ACQUITY™ BEH C18 column (100mm×2.1mm i.d., 1.7μm) using a gradient mobile phase system of acetonitrile-water containing 0.05% formic acid and 5mM ammonium formate. The triple quadruple mass spectrometer was set in negative electrospray ionization mode and multiple reaction monitoring (MRM) was used for six steroidal saponins quantification. The precursors to produce ion transitions monitored for TH1, TE1, TE, TB-II, TB-III, AS-I and IS were m/z 1211.5>1079.6, 935.5>773.4, 935.4>773.5, 919.6>757.4, 901.5>739.3, 757.4>595.3 and 637.3>475.3, respectively. The method validation was conducted over the curve range of 0.5-400ng/mL for the six saponins. The intra- and inter-day precisions (RSD%) were less than 9.4% and the average extraction recoveries ranged from 82.5% to 97.8% for each analyte. Six steroidal saponins were proved to be stable during sample storage, preparation and analytical procedures. The validated method was successfully applied for the first time to determine the concentrations of six main steroidal saponins in incurred rat plasma samples, after intragastric administration of the extract of Anemarrhena asphodeloides Bge. for a rat pharmacokinetic study.

Rapid metabolic discrimination and prediction of dioscin content from African yam tubers using Fourier transform-infrared spectroscopy combined with multivariate analysis

To determine whether or not FT-IR spectroscopy could be used for taxonomic and metabolic discrimination of African yam lines, tuber samples from African and Asian yam species were subjected to FT-IR. Most remarkable spectral differences between African and Asian yams were found in the 1750-1700 cm(-1) region, polysaccharide (1200-900 cm(-1)) and protein/amide I and II (1700-1500 cm(-1)) regions of FT-IR spectra. A hierarchical dendrogram based on partial least square-discriminant analysis (PLS-DA) of FT-IR data from 7 African yam species show phylogenetic relationship. In addition, the content of dioscin, a steroidal saponin found in yam tuber, was predicted using a PLS regression model with regression coefficient R(2)=0.7208 indicated that prediction model had average accuracy. Thus, considering these results we suggest that FT-IR combined with multivariate analysis could be applied as a novel tool for metabolic evaluation and high-throughput screening of African yam lines with higher content of dioscin.

Quality control and identification of steroid saponins from Dioscorea zingiberensis C. H. Wright by fingerprint with HPLC-ELSD and HPLC-ESI-Quadrupole/Time-of-fight tandem mass spectrometry

In this study, a fingerprint of steroid saponins, the major bioactive constituents in the crude extracts from Dioscorea zingiberensis C. H. Wright (DZW), has been established for the first time by combined use of the following two methods: high-performance liquid chromatography coupled with evaporative light scattering detector (HPLC-ELSD) and the simultaneous characterization of the steroid saponins by high-performance liquid chromatography coupled with electrospray ionization-mass spectrometry and quadrupole tandem time-of-fight mass analyzers detection (HPLC-ESI-Q/TOF). All HPLC analyses were carried out on a Welchrom C18 column (250mm×4.6mm I.D., 5μm) with a mobile phase composed of water and acetonitrile under gradient elution. There were 68 common characteristic peaks in the fingerprints, in which 12 of them were confirmed by comparing their mass spectra and retention times with those of the reference compounds. In order to identify other unknown peaks, their fragmentation behaviors characteristic of the major groups of steroid saponins from DZW with six types of aglycone skeletons were discussed in detail, and possible MS/MS fragmentation pathways were proposed for aiding the structural identification of these components. According to the summarized fragmentation patterns, these peaks were tentatively assigned by matching their empirical molecular formula with those of the published compounds, or by elucidating their quasi-molecular ions and fragment ions referring to available literature information when the reference standards were unavailable. As a result, 22 new steroid saponins were found in DZW for the first time. In addition, the quantitative analysis of the nine (except for the reference compounds A, B, and C) known peaks was accomplished at the same time which indicated that there was a great variability in the amount of these active compounds in different batches in the crude extracts. This approach could demonstrate that the fingerprint could be considered to be a suitable tool to comprehensively improve the quality control of DZW. The identification and structural elucidation of the peaks in the fingerprint may provide important experimental data for further pharmacological and clinical researches.

Preparation of progenin III from total steroidal saponins of Dioscorea nipponica Makino using a crude enzyme from Aspergillus oryzae strain

Progenin III, one of the most active spirostanol saponins, is a potential candidate for anti-cancer therapy due to its strong antitumor activity and low hemolytic activity. However, the concentration of progenin III is extremely low in natural Dioscorea plants. In this paper, the progenin III production from total steroidal saponins of Dioscorea nipponica Makino was studied using the crude enzyme from Aspergillus oryzae DLFCC-38. The crude enzyme converting total steroidal saponins into progenin III was obtained from the A. oryzae DLFCC-38 culture. For enzyme production, the strain was cultured for 72 h at 30 °C with shaking at 150 rpm in 5 % (w/v) malt extract medium containing 2 % (v/v) extract of D. nipponica as the enzyme inducer. The crude enzyme converted total steroidal saponins into major progenin III with a high yield when the reaction was carried out for 9 h at 50 °C and pH 5.0 with the 20 mg/ml of substrate. In the preparation of progenin III, 117 g of crude progenin III was obtained from 160 g of substrate, and the crude product was purified with silica gel column to obtain 60.3 g progenin III of 93.4 % purity.

Application of high-speed countercurrent chromatography-evaporative light scattering detection for the separation of seven steroidal saponins from Dioscorea villosa

INTRODUCTION

Steroidal saponins in Dioscorea species are chemically characterised as spirostanol and furostanol saponins, and have been used as standard marker compounds due to their chemotaxonomical significance and their important biological activities.

OBJECTIVE

To design a simple, rapid and efficient method for the separation of steroidal saponins with a high degree of purity using high-speed countercurrent chromatography (HSCCC) coupled with evaporative light scattering detection (ELSD).

METHODOLOGY

In the first step, reversed-phase mode HSCCC (flow rate: 1.5 mL/min; revolution speed: 800 rpm) using n-hexane:n-butanol:water [3:7:10 (v/v/v)] was employed to separate furostanol saponins from n-butanol soluble extracts of Dioscorea villosa. After the first HSCCC run, spirostanol saponins retained in the stationary phase were subjected to the second HSCCC (normal-phase mode; flow rate: 2.0 mL/min; revolution speed: 800 rpm). A two-phase solvent system composed of chloroform:methanol:isopropanol:water [10:6:1:4 (v/v/v/v)] was employed in the second HSCCC. The structures of isolates were elucidated by (1) H-NMR, (13)  C-NMR, ESI-MS and HPLC analysis.

RESULTS

Three furostanol saponins, parvifloside (27.3 mg), methyl protodeltonin (67.1 mg) and trigofoenoside A-1 (18.5 mg) were isolated from the n-butanol soluble extract of D. villosa by the first HSCCC run. Subsquent normal-phase HSCCC of the spirostanol-rich extract led to the separation of four spirostanol saponins: zingiberensis saponin I (15.2 mg), deltonin (31.5 mg), dioscin (7.7 mg) and prosapogenin A of dioscin (3.4 mg).

Screening and determination for potential α-glucosidase inhibitors from leaves of Acanthopanax senticosus harms by using UF-LC/MS and ESI-MS(n)

INTRODUCTION

Acanthopanax senticosus Harms is a typical Chinese herb with flavonoids existing in all parts of the plant but with the largest content in leaves. However, leaves have been neglected in past research. To investigate the potential use of leaves of A. senticosus Harms for discovering lead compounds to treat type 2 diabetes, the herb leaves were selected for screening the potential of α-glucosidase inhibitors.

OBJECTIVE

To screen for candidates of α-glucosidase inhibitors from leaves of A. senticosus Harms and evaluate the structure-activity relationship of the α-glucosidase inhibitors.

METHODOLOGY

Ultrafiltration liquid chromatography/mass spectrometry (UF-LC/MS) assay was developed for screening candidates of α-glucosidase inhibitors from leaves of A. senticosus Harms. The interesting compounds were identified by using reversed-phase high performance liquid chromatography with diode array detector and electrospray ionisation multiple-stage tandem mass spectrometry (RP-HPLC-DAD-ESI-MS(n) ), and confirmed by using electrospray ionisation Fourier transform ion cyclotron resonance multiple-stage tandem mass spectrometry (ESI-FT-ICR-MS(n)). Furthermore, the α-glucosidase inhibitory activity of the compounds detected was estimated using in vitro assays.

RESULTS

Eight compounds that might bind to α-glucosidase were screened and seven of them were identified successfully. The α-glucosidase inhibitory activity of the related compounds in leaves of A. senticosus Harms was determined.

CONCLUSION

The results obtained provided new information for the discovery of potential α-glucosidase inhibitors and the potential anti-diabetic application of the leaves of A. senticosus Harms.

Dioscorea nipponica Makino inhibits migration and invasion of human oral cancer HSC-3 cells by transcriptional inhibition of matrix metalloproteinase-2 through modulation of CREB and AP-1 activity

Oral cancer mortality has increased during the last decade due to the difficulties in treating related metastasis. Dioscorea nipponica Makino, a popular folk medicine, exerts anti-obesity and anti-inflammation properties. However, the effect of this folk medicine on metastasis of oral cancer has yet to be fully elucidated. The present study demonstrates that D. nipponica extracts (DNE), at a range of concentrations (0-50 μg/mL), concentration-dependently inhibited migration/invasion capacities of human oral cancer cells, HSC-3, without cytotoxic effects. The anti-migration effect of DNE was also observed in two other OSCC cell lines, Ca9-22 and Cal-27. Zymography, real time PCR, and Western blotting analyses revealed that DNE inhibited matrix metalloproteinase-2 (MMP-2) enzyme activity, and RNA and protein expression. The inhibitory effects of DNE on MMP-2 proceeded by up-regulating tissue inhibitor of metalloproteinase-2 (TIMP-2), as well as suppressing nuclear translocation and DNA binding activity of cAMP response element-binding (CREB) and activating protein-1 (AP-1) on the MMP-2 promoter in HSC-3 cells. In conclusion, DNE inhibited the invasion of oral cancer cells and may have potential use as a chemopreventive agent against oral cancer metastasis.

Neurotrophic activity of DA-9801, a mixture extract of Dioscorea japonica Thunb. and Dioscorea nipponica Makino, in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Dioscorea japonica Thunb. has been traditionally used to treat polyuria and diabetes in Korea.

AIM OF THE STUDY

We previously report the effects of Dioscorea japonica Thunb. extract on glucose control, NGF induction, and neuroprotection in a rodent diabetic model. Since the most potent fraction, DA-9801, was identified from a mixture of Dioscorea japonica Thunb. (DJ) and Dioscorea nipponica Makino (DN) following bioactivity-guided fractionation, here, we investigated the potential mechanism of the extract activity against diabetic peripheral neuropathy (DPN).

MATERIALS AND METHODS

A 1:3 mixture of DJ and DN was extracted with ethanol (DA-9801) and further fractionated into an ethylacetate-soluble fraction (DA-9801E). Effects of these extracts on neurite outgrowth were measured in PC-12 cells and DRG neurons. Effects on cell viability and TrkA phosphorylation were evaluated in PC-12 cells. NGF induction effect was determined in primary Schwann cells as well as IMS32 cells (immortalized Schwann cells).

RESULTS

No cytotoxicity was observed in PC-12 cells at the concentration below 500 μg/ml of either DA-9801 or DA-9801E. DA-9801 and DA-9801E at 100 μg/ml and 10 μg/ml, respectively, showed a significant effect on neurite outgrowth in PC-12 cells and DRG neurons in the presence of or absence a low concentration of NGF (2 ng/ml). The Trk-A phosphorylation effect of DA9801 was confirmed in PC-12 cells. An NGF induction effect of these extracts was not detected in either IMS-32 cells, or primary Schwann cells.

CONCLUSIONS

The NGF agonistic activity of DA-9801 and DA-9801E was demonstrated, which may contribute to their neuroprotective effect against DPN. Studies of the detailed mechanism of these extracts as well as identification of the active components are warranted for the development of an anti-DPN drug from DJ and DN.

Anti-thrombosis effect of diosgenin extract from Dioscorea zingiberensis C.H. Wright in vitro and in vivo

Thrombus formation in blood vessel plays an important role in the pathogenesis and progression of atherosclerosis and cardiovascular diseases. Extract of Dioscorea zingiberensis C.H. Wright (D. zingiberensis) is demonstrated to posses activities for curing cardiovascular diseases such as coronary heart disease and angina pectoris. However, there were few studies on anti-thrombosis activity of it. We investigated the anti-thrombosis effect of diosgenin from D. zingiberensis (Dio) in vitro and in vivo on inferior vena cava ligation thrombosis rat model and pulmonary thrombosis mice model. We evaluated the protective effect of Dio by measuring the platelet aggregation, activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT) and the venous thrombosis in rats and the bleeding time, clotting time and protection rate in mice. Results showed that Dio inhibited platelet aggregation, thrombosis and prolonged APTT, PT and TT in rats in a dose-dependent manner. They also prolonged the bleeding time, clotting time and increased protection rate in mice in a dose-dependent manner. Taken together, these findings suggested that Dio which contained 95% diosgenin had anti-thrombosis activity. Dio executives the anti-thrombosis activity through improving the anticoagulation function, inhibiting platelet aggregation and thrombosis.

Estrogen receptor mediates the effects of pseudoprotodiocsin on adipogenesis in 3T3-L1 cells

Estrogen receptors (ERs) play a pivotal role in adipogenesis; therefore, compounds targeting ERs may also affect fat formation. Recent studies have shown that the Dioscorea plant (commonly called yam) exhibits an antiobesity effect on rodents. However, the active compounds and underlying mechanisms responsible for this effect are not yet fully understood. We evaluated the effects of pseudoprotodiocsin (PPD), a steroid saponin from Dioscorea nipponica Makino (a type of Dioscorea), on adipogenesis and the mechanisms underlying this effect. Treatment with PPD at the onset of adipogenic differentiation resulted in significantly decreased adipogenesis in both in vitro and in vivo experimental systems. An increased amount of ERalpha mRNA, protein, and the accumulation of ERalpha in the nucleus were also observed. However, the expression pattern of ERbeta was not altered. Furthermore, the antiadipogenic effect of PPD was found to be ER dependent. It was also accompanied by the decreased expression of several genes involved in adipogenesis, including lipoprotein lipase (LPL), leptin, CCAAT/enhancer-binding-protein-alpha (C/EBPalpha), and peroxisome proliferator-activated receptor-gamma (PPARgamma), as well as the increased expression of some negative factors of adipogenesis, including preadipocyte factor 1 (Pre-1), GATA-binding protein 2 (GATA-2), GC-induced leucine-zipper protein (GILZ), and C/EBP homologous protein (CHOP-10). In addition to its estrogenic action, PPD also abolished the p38 mitogen-activated protein kinase (p38 MAPK) activation. Our results suggest that PPD inhibits adipogenesis in an ER-dependent manner and induces the expression of ERalpha. These findings may provide a lead toward a novel agent that can be used to treat obesity.

Acute toxicity and sub-chronic toxicity of steroidal saponins from Dioscorea zingiberensis C.H.Wright in rodents

ETHNOPHARMACOLOGICAL RELEVANCE

Steroidal saponins from Dioscorea zingiberensis are widely used in China for curing cardiovascular diseases. However, there was little toxicological information available on them.

AIM OF THE STUDY

The study evaluated potential toxicity of the steroidal saponins and analyzed the metabolites in rats.

MATERIALS AND METHODS

For the acute study, the steroidal saponins were administered to kunming mice in single doses of 112.5-9000 mg/kg given by gavage. General behavior adverse effects, mortality and liver histopathological changes were examined. For the sub-chronic toxicity study, Sprague-Dawley rats were gavaged at doses of 127.5, 255 and 510 mg/kg/day for 30 days, then examined the biochemical and hematological parameters. Metabolites in serum were analyzed by HPLC-MS.

RESULTS

The steroidal saponins caused dose-dependent general behavior adverse effects, mortality and liver histopathological changes in the acute toxicity study. In the sub-chronic toxicity study, 510 mg/kg/day of steroidal saponins increased total bilirubin (TBIL) in serum and decreased protein content in liver significantly. The metabolic process of TBIL in liver includes TBIL intaking, conjugated bilirubin forming, conjugated bilirubin excreting to biliary passage. Treatment with high dose of the steroidal saponins in vivo may lead to vacuolization of the cytoplasm of hepatocytes and canalicular cholestasis. In all doses used in the experiment, the steroidal saponins decreased aspartate aminotransferase (GOT), alanine aminotransferase (ALT) and alkaline phosphatase (AKP) in serum and increased reduced glutathione hormone (GSH), glutathione reductase (GR) and glutathione S-transferases (GST) in liver. Diosgenin was the main metabolite in serum.

CONCLUSIONS

The steroidal saponins did not show any sign of toxicity up to oral dose of 562.5mg/kg in mice. No significant changes of biochemical and hematological parameters in rats (except at 510 mg/kg/day), it was concluded that the steroidal saponins did not appear to have significant toxicity in their traditional uses.

O-glycoside sequence of pentacyclic triterpene saponins from Phytolacca bogotensis using HPLC-ESI/multi-stage tandem mass spectrometry

INTRODUCTION

The lack of pharmacopoeial methodologies for the quality control of plants used for therapeutic purposes is a huge problem that impacts directly upon public health. In the case of saponins, their great structural complexity, weak glycoside bonds and high polarity hinder their identification by conventional techniques.

OBJECTIVE

To apply high-performance liquid chromatography-electrospray tandem mass spectrometry (HPLC-ESI/MS(n)) to identify the O-glycoside sequence of saponins from the roots of Phytolacca bogotensis.

METHODOLOGY

Saponins were isolated by preparative HPLC and characterised by NMR spectroscopic experiments. Collision-induced dissociation (CID) of isolated saponins was performed producing typical degradation reactions that can be associated with several glycosidic bonds as empirical criteria. A method using solid-phase extraction (SPE) and HPLC/ESI-MS(n) for the characterisation of saponins and identification of novel molecules is described.

RESULTS

Three saponins reported for the first time in P. bogotensis were isolated and characterised by NMR spectroscopy. Characteristic cross ring cleavage reactions have been used as empirical criteria for the characterisation of the glycosidic bonds most frequently reported for Phytolacca saponins. One new saponin was proposed on the basis of empirical criteria, and other five saponins were identified for the first time for P. bogotensis using HPLC-ESI/MS(n).

CONCLUSION

Electrospray ionisation in combination with tandem mass spectrometry has been established as a powerful tool for the profiling of saponins from roots of P. bogotensis. CID proved to be a useful tool for the characterisation and identification of known and novel saponins from the plant family Phytolaccaceae and can be used for quality control purposes of crude plant extracts.

Isolation and tandem mass fragmentations of an anti-inflammatory compound from Aralia elata

One-step isolation of a saponin from Aralia elata was undertaken using high-speed countercurrent chromatography coupled with evaporative light scattering detection. A triterpenoid saponin, elatoside F, was purified with 96.8% purity using a two-phase-system comprising chloroform-methanol-water-isopropanol. The yield was 35.0 mg from 348.2 mg of the enriched saponin fraction. In vitro anti-inflammatory study demonstrated that elatoside F inhibited lipopolysaccharide-induced nitric oxide production, as well as nuclear factor kappaB activation, in a dose-dependent manner. Two types of mass ionization technique were compared on elatoside F to investigate characteristic fragmentation patterns. MALDI-TOF tandem mass spectrometric fragmentation patterns of sodiated ions provided structural information on glycosidic cleavages and on extensive cross-ring cleavages. Electrospray ionization multiple-stage tandem mass fragmentation of both sodiated and lithiated ions could provide information on glycosidic cleavages. All observed tandem mass fragmentation spectra provided valuable elatoside F structural information when unknown samples from crude extracts are under screening by mass spectrometry.