Characterization of steroidal saponins in crude extracts from Dioscorea zingiberensis C. H. Wright by ultra-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry

Characterisation of bioactive compounds from leaves of Smilax fluminensis Steud. by gc-MS and LC-DAD-MS, and analysis of its antioxidant and ecotoxicological activities

Smilax fluminensis Steud. is distributed in Central and South America, commonly named as 'salsaparilha' or 'japicanga'. In the present work, the chemical composition was determined, antioxidant and cytotoxic effects were evaluated for the ethanol extract (EE) and fractions from leaves. Fatty acid esters and phytol were characterised in the hexane (HEX) fraction. O-glycosylated flavonols and flavones, caffeic acid derivatives, and steroidal saponins were annotated for EE, and dichloromethane (DCM), ethyl acetate (AC), and hydroethanol (HE) fractions. The samples contain flavonoids and phenolic compounds, and the AC fraction displayed the biggest concentration of these substances. Antioxidant potential was observed in all samples, being especially pronounced in the AC fraction by DPPH and FRAP assays, with IC50 values of 8.18 and 2.35 µg/mL, respectively. AC and HEX fractions showed 35% and 5% lethality at 1000 μg/mL, in the Artemia salina assay, and the other samples did not show a toxic effect.

Bioactive saponin profiling of endophytic fungi from Asparagus racemosus

Thirty-five distinct endophytic fungi were isolated from the roots of Asparagus racemosus. Five out of 35 isolates were found to be efficient saponins producers and they were identified as Aspergillus terreus (E.F-1), Aspergillus flavus (E.F-7), Penicillium sp. (E.F-12), Talaromyces pinophilus(S-26), and Aspergillus terreus (Y-2) based on 18 sr RNA sequencing. The crude extracts of endophytic fungi were screened using High-performance liquid chromatography (HPLC) for quantitative analysis of saponin. The crude extracts of endophytic fungi were also characterised using FT-IR spectroscopy and mass spectrometry. The IR spectra of all five endophytic fungi crude extracts revealed the presence of -OH,-CH Alkyl,-CH3,-C-O-C,-C=C,-C=O stretching, which indicated the presence of saponin. Eight types of saponins recognised by mass spectrometry were Cyclamine saponin, Aspoligonin A, Sarsapogenin, Asparacosin A, Schidigera saponinD5, Aspargoside A, Dioscin, and Protodioscin. Endophytic fungi extracts also exhibited antimicrobial activity and antioxidant activity.

Oxidative Stress and DNA Damage Effect of Dioscorea hispida Dennst. on Placental Tissues of Rats

Dioscorea hispida Dennst. locally known as “ubi gadung” has been used as a traditional remedy and source of carbohydrate among Malaysians. To assess the effect of Dioscorea hispida aqueous extract (DHAE) on the production of reactive oxygen species (ROS) and their effects on DNA damage in Sprague Dawley rat’s placental tissues, pregnant rats were randomly divided into four groups. The animals were orally treated with distilled water (negative control) and three different concentrations of DHAE (250, 500 and 1000 mg/kg body weight (BW)) from gestation day 6 until 20. The oxidative stress in placental tissues was evaluated at day 21 by measuring the level of ROS, superoxide dismutase (SOD) and lipid peroxidation biomarker, malondialdehyde (MDA) while comet assay was used for DNA damage. There was no significant production of ROS and SOD activities in all groups. Significant changes were observed in the MDA level at 1000 mg/kg BW DHAE. Comet assay revealed a significant increase (p < 0.05) of DNA damage on animals treated with 250 and 500 mg/kg BW DHAE but not at the highest concentration. It was postulated that the placental cells could have undergone necrosis which destroys all components including DNA. This occurrence simultaneously reduces the levels of DNA damage which can be represented by lower level of tail moments. This finding correlates with our histopathological examination where necrotic cells of spongiotrophoblast were observed in the basal zone of placental tissue. The high amount of hydrogen cyanide and other compounds in 1000 mg/kg BW DHAE could elevate the lipid peroxidation and directly induce cell necrosis which requires further investigation.

Zingiberensis Newsaponin Inhibits the Malignant Progression of Hepatocellular Carcinoma via Suppressing Autophagy Moderated by the AKR1C1-Mediated JAK2/STAT3 Pathway

Objective

Saponins are a group of compounds from various plants, which exhibit an anticancer activity. This study aimed to explore the anticancer effect of zingiberensis newsaponin (ZnS) against hepatocellular carcinoma (HCC) and the underlying mechanism involving autophagy.

Methods

HCC cells (Huh7 and SMMC7721) were treated with ZnS and/or 3-MA. The cell viability, migration, and apoptosis were determined using CCK-8 assay, transwell assay, and flow cytometry, respectively. The levels of oxidative stress markers (ROS, SOD, and MDA) were measured by ELISA assay. Autophagy was monitored using MDC assay, immunofluorescence staining, and transmission electron microscopy. The relative protein expression of LC3II/LC3I, P62, AKR1C1, p-JAK2, p-STAT3, JAK2, and STAT3 was determined using Western blot.

Results

ZnS or 3-MA inhibited the cell viability and migration, and it promoted cell apoptosis and oxidative stress in HCC. MDC-positive cells and autophagosomes were reduced by ZnS or 3-MA treatment. The expression of autophagy-related proteins LC3 (LC3II/LC3I) and P62 was, respectively, downregulated and upregulated after ZnS or 3-MA treatment. In addition, ZnS or 3-MA suppressed the protein expression of AKR1C1, p-JAK2, and p-STAT3 in HCC cells. Furthermore, the above phenomena were evidently enhanced by ZnS combined 3-MA treatment. AKR1C1 overexpression weakened the effect of ZnS on inhibiting the expression of AKR1C1, p-JAK2, and p-STAT3.

Conclusion

ZnS exerts an anticancer effect on HCC via inhibiting autophagy moderated by the AKR1C1-mediated JAK2/STAT3 pathway. ZnS and 3-MA exert a synergistic effect on inhibiting HCC.

Dioscorea Zingiberensis New Saponin Inhibits the Growth of Hepatocellular Carcinoma by Suppressing the Expression of Long Non-coding RNA TCONS-00026762

Background: The etiology and carcinogenesis of hepatocellular carcinoma (HCC) are associated with various risk factors. Saponins extracted from Dioscorea zingiberensis C. H. Wright exhibit antitumor activity against HCC. This study aimed to investigate the effect and the underlying mechanism of Dioscorea Zingiberensis new saponin (ZnS) on HCC. Methods: Human HCC cell lines, Huh7 and SMMC-7721, were treated with different concentrations of ZnS. Cell apoptosis was determined via flow cytometry assay. Differentially expressed lncRNAs (DElncRNAs) in ZnS-treated SMMC-7721 cells were determined through RNA-sequence. The role of lncRNA TCONS-00026762 in HCC was investigated gain of function analysis, along with cell proliferation, apoptosis, and invasion in HCC cells. A subcutaneous xenograft of SMMC-7721 cell lines was established to study the effects of TCONS-00026762 in vivo. The expression of apoptosis-related proteins was detected in vivo and in vitro via western blotting. Results: ZnS inhibited the proliferation of HCC cell in a dose-dependent manner. ZnS could induce apoptosis in HCC cells. Illumina sequencing results showed that 493 DElncRNAs were identified in ZnS-treated SMMC-7721 cells. TCONS-00026762 expression was down-regulated in the ZnS-treated SMMC-7721 cells. TCONS-00026762 inhibited the effect of ZnS on the proliferation, apoptosis, and invasion of HCC cells. ZnS inhibited the tumor growth, while, TCONS-00026762 promoted tumor growth in vivo. Furthermore, ZnS and TCONS-00026762 regulated cell apoptotic pathways. Conclusion: ZnS significantly inhibits the viability, apoptosis, invasion, and tumorigenicity of HCC cells by regulating the expression of TCONS-00026,762. Our findings provide novel insights into the potential role of lncRNA in HCC therapy.

Rapid Screening and Characterization of Triterpene Saponins from the Root of Phytolacca acinosa Roxb by High-Performance Liquid Chromatography Coupled to Electrospray Ionization and Quadrupole Time-of-Flight Mass Spectrometry

Triterpene saponins (TSs) are important bioactive constituents with structural diversity widely distributed in many plants. The root of Phytolacca acinosa Roxb (RPa) has been used as a traditional Chinese medicine. However, TSs as the main active ingredients in RPa have not been fully characterized. Here, we profiled TSs from RPa by high-performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS/MS). We tentatively identified 29 TSs, including 13 that had not been reported previously from this plant. This study indicates that HPLC-ESI-QTOF-MS/MS is an effective and rapid method for the characterization of complicated TSs in herbal extracts.

The Dioscorea Genus (Yam)-An Appraisal of Nutritional and Therapeutic Potentials

The quest for a food secure and safe world has led to continuous effort toward improvements of global food and health systems. While the developed countries seem to have these systems stabilized, some parts of the world still face enormous challenges. Yam (Dioscorea species) is an orphan crop, widely distributed globally; and has contributed enormously to food security especially in sub-Saharan Africa because of its role in providing nutritional benefits and income. Additionally, yam has non-nutritional components called bioactive compounds, which offer numerous health benefits ranging from prevention to treatment of degenerative diseases. Pharmaceutical application of diosgenin and dioscorin, among other compounds isolated from yam, has shown more prospects recently. Despite the benefits embedded in yam, reports on the nutritional and therapeutic potentials of yam have been fragmented and the diversity within the genus has led to much confusion. An overview of the nutritional and health importance of yam will harness the crop to meet its potential towards combating hunger and malnutrition, while improving global health. This review makes a conscious attempt to provide an overview regarding the nutritional, bioactive compositions and therapeutic potentials of yam diversity. Insights on how to increase its utilization for a greater impact are elucidated.

Metabolomic profiling of five Agave leaf taxa via UHPLC/PDA/ESI-MS inrelation to their anti-inflammatory, immunomodulatory and ulceroprotective activities

Agave plants are popular for their myriad applications in traditional medicine attributed to their reported anti-inflammatory, immunomodulatory, cytotoxic and antifungal activities. The aim of this study was to examine the anti-inflammatory, immunomodulatory and ulceroprotective activity of Agave species in relation to their metabolite fingerprint via a metabolome based ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) approach coupled to chemometrics. The metabolomic differences among five examined Agave leaves viz. Agave americana L., A. americana var. marginata Trel, A. angustifolia Haw. cv. marginata, A. desmettiana Jacobi, A. pygmaea Gentry were determined via a total of 56 annotated metabolites. Identification based on MSⁿ and UV spectra revealed 25 steroidal saponins and sapogenins, 6 flavonoids, 2 homoisoflavonoids, 7 phenolic acids, 6 fatty acids and 3 fatty acid amides, some of which are reported for the first time in Agave. Metabolites heterogeneity was assessed among leaf taxa via multivariate data analyses for samples classification, showing that saponins is the major metabolite contributing to their classification. The carrageenan induced acute inflammatory rat model was used to assess the anti-inflammatory activity of Agave extracts via monitoring of blood cytokine levels. Additionally, their effects on ethanol-induced gastric ulcer in rats were evaluated. A. pygmaea showed the most significant anti-inflammatory and immunomodulatory activity, while A. angustifolia var. marginata possessed the highest ulceroprotective activity, which could be attributable to the high abundance of various saponins and homoisoflavonoids in those taxa.

Potential of Neglected and Underutilized Yams (Dioscorea spp.) for Improving Nutritional Security and Health Benefits

Food and nutritional security are the major concerns in many countries of the world and may have potential to contribute to sustainable food systems under climate change. To address the food and nutritional insecurity, it has become extremely important to diversify the present-day agricultural system as well as to search for alternative food and feed ingredients. Some wild root and tuber crops occupy a remarkable position toward food security of the developing world due to their high calorific value and superior carbohydrate content. Yam (Dioscorea spp.) provides food and medicines to millions of people in the world especially in the tropics and sub tropics. It is recognized as the fourth most important tuber crop after potatoes, cassava, and sweet potatoes. It contributes about 10% of the total root and tubers production around the world. Yams also considered as famine food and plays a prime role in the food habit of small and marginal rural families and forest-dwelling communities during the food scarcity periods. These species are unique for their food, medicinal and economic values but their wider utilization is limited due to the presence of anti-nutritional compositions. This paper describes the ethnobotany of yam species in relation to their nutritional, anti-nutritional and pharmacological properties and highlights the potentiality for food and nutritional security for combating the “hidden hunger” caused by micronutrient deficiencies.

Chemotaxonomic studies of 12 Dioscorea species from China by UHPLC-QTOF-MS/MS analysis

INTRODUCTION

Dioscorea species, which contain abundant steroidal saponins, have been used as folk medicines or raw materials to synthesise steroid drugs.

OBJECTIVE

To establish a rapid chemotaxonomic method that will comprehensively resolve confusions about genetic relationships of genus Dioscorea.

METHODS

A comprehensive strategy using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS) was firstly proposed to evaluate the chemotaxonomy of 12 species (27 taxa) from China by hierarchical cluster analysis (HCA) based on the variations of the identified metabolites.

RESULTS

Twenty-eight secondary metabolites (mainly steroidal saponins) were identified. The MSⁿ fragmentation patterns of DA (a new acetylated steroidal saponin at C-7 position) were firstly reported. Moreover, eight major steroidal saponins were further quantified simultaneously by UPLC-QTOF-MS method. According to HCA results, D. bulbifera L. was distinguished with species of sect. Stenophora Uline for pennogenin-type steroidal saponins. Dioscorea zingiberensis exhibited far distance from other members of sect. Stenophora Uline for two unique saponins. Dioscorea banzhuana may be reclassified into sect. Stenophora. Dioscorea nipponica subsp. rosthornii and D. collettii var. hypoglauca might be separated from their original subspecies/varieties as new species, respectively.

CONCLUSION

The chemotaxonomic method was successfully applied in the study of genetic relationships of Dioscorea species. This study not only enhanced the understanding of chemical constituents, but also laid basic theoretical foundations for the rational utilisation and chemotaxonomy of genus Dioscorea.

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.

Dioscorea zingiberensis C. H. Wright: An overview on its traditional use, phytochemistry, pharmacology, clinical applications, quality control, and toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Dioscorea zingiberensis C. H. Wright (D. zingiberensis), Dioscoreaceae, is used extensively in traditional Chinese medicines. The aim of the current review paper is to give a comprehensive overview of the traditional usage and phytochemistry of the plant. Clinical studies performed and products prepared from the plant and active principles will be mentioned. In addition a review of the taxonomy of the genus Dioscorea is given.

MATERIALS AND METHODS

A systematic search on literature has been performed in databases like Google Scholar, Science Direct, Scifinder, Web of Science, and in Chinese databases (China Knowledge Resource Integrated, i.e., CNKI and Wanfang) including Ph.D. and M.Sc. dissertations. These from the period 1983-2016 have been searched.

RESULTS

D. zingiberensis is an endemic plant in China widely distributed in some provinces, especially Hubei and Shaanxi. The rhizomes are the medicinal part in Dun-Ye-Guan-Xin-Ning tablets and are used for isolation of diosgenin. Steroidal saponins are believed to be the active principles. More than 70 compounds have been identified. Several of these have been tested in preclinical assays and clinical trials. A wide spectrum of biological effects including cardiovascular, anti-thrombosis, hyperlipidemia, neuroprotection, anti-inflammatory, and anthelmintic effect has been verified.

CONCLUSIONS

Because of the promising results from the investigations on the plant material of D. zingiberensis, further in depth analyses ought to be performed to evaluate its potential as either a traditional drug or a source of bioactive principle. The presently performed studies do not explain mechanism of action, pharmacokinetics (ADME properties), or toxicity. All of these topics need more elaborate investigations.

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.

Comparative Transcriptome Analysis Identifies Putative Genes Involved in Dioscin Biosynthesis in Dioscorea zingiberensis

Dioscorea zingiberensis is a perennial herb native to China. The rhizome of D. zingiberensis has long been used as a traditional Chinese medicine to treat rheumatic arthritis. Dioscin is the major bioactive ingredient conferring the medicinal property described in Chinese pharmacopoeia. Several previous studies have suggested cholesterol as the intermediate to the biosynthesis of dioscin, however, the biosynthetic steps to dioscin after cholesterol remain unknown. In this study, a comprehensive D. zingiberensis transcriptome derived from its leaf and rhizome was constructed. Based on the annotation using various public databases, all possible enzymes in the biosynthetic steps to cholesterol were identified. In the late steps beyond cholesterol, cholesterol undergoes site-specific oxidation by cytochrome P450s (CYPs) and glycosylation by UDP-glycosyltransferases (UGTs) to yield dioscin. From the D. zingiberensis transcriptome, a total of 485 unigenes were annotated as CYPs and 195 unigenes with a sequence length above 1000 bp were annotated as UGTs. Transcriptomic comparison revealed 165 CYP annotated unigenes correlating to dioscin biosynthesis in the plant. Further phylogenetic analysis suggested that among those CYP candidates four of them would be the most likely candidates involved in the biosynthetic steps from cholesterol to dioscin. Additionally, from the UGT annotated unigenes, six of them were annotated as 3-O-UGTs and two of them were annotated as rhamnosyltransferases, which consisted of potential UGT candidates involved in dioscin biosynthesis. To further explore the function of the UGT candidates, two 3-O-UGT candidates, named Dz3GT1 and Dz3GT2, were cloned and functionally characterized. Both Dz3GT1 and Dz3GT2 were able to catalyze a C3-glucosylation activity on diosgenin. In conclusion, this study will facilitate our understanding of dioscin biosynthesis pathway and provides a basis for further mining the genes involved in dioscin biosynthesis.

Safety investigation on total steroid saponins extracts from Dioscorea zingiberensis C.H. Wright: Sub-acute and chronic toxicity studies on dogs

Sub-acute and chronic toxic effects of total steroidal saponins (TSSN) extracts from Dioscorea zingiberensis C.H. Wright on various internal organs and biochemical indicators have never been studied before and this study is the first of its kind to demonstrate sub-acute and chronic toxicities of TSSN on dogs. Administration of TSSN extracts at doses up to 3000 mg/Kg daily for 14 days, no biochemical and organ changes were observed on the experimental groups of dogs. Further, chronic toxicity study through oral administration of TSSN extracts at the gradual doses of 50, 250 and 500 mg/Kg for 90 days followed by a 2-week recovery assay revealed absence of significant architectural and morphological changes in internal organs which were confirmed through histopathological examination and merely no significant alteration in the biochemical indicators including hematologic and urine analysis and electrocardiogram compared to the control dogs. This toxicological evaluation came across with the finding that the herbal preparation can be considered as nontoxic and animals could tolerate the extracts at doses up to 500 mg/Kg with LD₅₀ greater than 3000 mg/Kg. It may serve as a preliminary scientific evidence for further therapeutic investigations.

Comparative metabolic profiling of Costus speciosus leaves and rhizomes using NMR, GC-MS and UPLC/ESI-MS/MS

Costus speciosus had been used in oriental systems of medicines, to treat diverse ailments. The present study was focused on NMR, GC-MS and UPLC/ESI-MS/MS-based metabolic profiling of C. speciosus. This metabolic study resulted in the identification of 91 and quantification of 69 metabolites. Caffeic acid derivatives previously unreported in C. speciosus were also identified. High quantity of steroidal saponins namely methyl protogracillin (297.97 ± 0.07 mg/g dried wt.) and dioscin (158.72 ± 0.27 mg/g dried wt.) were observed in butanol fraction of rhizomes. Health care metabolites including caffeic acid (37.88 ± 0.04 mg/g dried wt.) and trehalose (75.12 ± 0.08 mg/g dried wt.) were also detected in ethyl acetate and aqueous fractions of rhizomes, respectively. Metabolites of nutraceutical and biological significance including eremanthine (5.14 ± 0.68%, peak area), tocopherols (~22%), sterols (~25%) were also identified from hexane fractions of rhizomes and leaves using GC-MS. The analytical techniques used had successfully differentiated metabolites composition among leaves and rhizomes.

Recent development in liquid chromatography stationary phases for separation of Traditional Chinese Medicine components

Traditional Chinese Medicine (TCM) is an ancient medical practice which has been used to prevent and cure diseases for thousands of years. TCMs are frequently multi-component systems with mainly unidentified constituents. The study of the chemical compositions of TCMs remains a hotspot of research. Different strategies have been developed to manage the significant complexity of TCMs, in an attempt to determine their constituents. Reversed-phase liquid chromatography (RPLC) is still the method of choice for the separation of TCMs, but has many problems related to limited selectivity. Recently, enormous efforts have been concentrated on the development of efficient liquid chromatography (LC) methods for TCMs, based on selective stationary phases. This can improve the resolution and peak capacity considerably. In addition, high-efficiency stationary phases have been applied in the analysis of TCMs since the invention of ultra high-performance liquid chromatography (UHPLC). This review describes the advances in LC methods in TCM research from 2010 to date, and focuses on novel stationary phases. Their potential in the separation of TCMs using relevant applications is also demonstrated.

Comparative studies on performance of CCC and preparative RP-HPLC in separation and purification of steroid saponins from Dioscorea zingiberensis C.H.Wright

Steroid saponins from Dioscorea zingiberensis C.H.Wright were separated for the first time using two chromatographic methods for comparison: counter-current chromatography (CCC) coupled with evaporative light scattering detector (ELSD) and preparative reversed phase high-performance liquid chromatography (RP-HPLC) with an ultraviolet detector. Ethyl acetate-n-butanol-methanol-water (4:1:2:4, v/v) was chosen as the two-phase solvent system for CCC, while the acetonitrile-water (25:75 for the first step and15:85 for the second step, v/v) was used as the mobile phase in the preparative RP-HPLC. The following five steroid saponins were purified by theses two chromatographic methods, in one-step operation by CCC and by two-step operation in preparative RP-HPLC: 1) 26-O-β-D- glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 26-triol-3-O-[β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside (compound A), 2) 26-O-β-D-glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 4) 26-triol-3-O-[β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside (compound B), 3) 26-O-β-D-glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)]-β-D-glucopyranoside (compound C), 4) 26-O-β-D-glucopyranosyl-(25R)-furost-5, 20(22)-diene-3β, 26-diol-3-O-{α-L-rhamnopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→2)]}-β-D-glucopyranoside (compound D) and 5) 26-O-β-D-glucopyranosyl-(25R)-furost-5, 20(22)-diene-3β, 26-diol-3-O-[β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosy-(1→2)]-β-D-glucopyranoside (compound E). The purities of these five steroid saponins separated by both methods were over 95%, and structural identification of these compounds was performed by ESI-MS, and ¹³C NMR. Comparison of these two established approaches revealed that CCC required a longer separation time but with less solvent consumption, whereas preparative RP-HPLC gave a shorter separation time but with higher solvent consumption. These results demonstrated that either of these two methods of different separation mechanism is feasible, economical and efficient for rapid preparative isolation and purification of steroid saponins from Dioscorea zingiberensis C.H.Wright.

Cardioprotective effect of total saponins from three medicinal species of Dioscorea against isoprenaline-induced myocardial ischemia

ETHNOPHARMACOLOGICAL RELEVANCE

As folk medicines used in China since 1950s, Dioscorea nipponica Makino (DN), D. panthaica Prain et Burkill (DP), and D. zingiberensis C.H. Wright (DZ) are regarded as having more or less the same traditional therapeutic actions, such as activating blood, relieving pain, and dispersing swelling. It is noteworthy that, of the 49 species of the genus Dioscorea distributed in China, based on such traditional efficacies, only these three have been further developed as effective single-herb medicines for treating cardiovascular diseases by the modern pharmaceutical industry. In our previous study, it was found that the chemical compositions of DN and DP were similar, and both were distinct from that of DZ. Hence, whether their different chemical profiles support their anti-IHD (ischemic heart disease) activity in common still needs to be answered. So far it is still unknown whether the efficacies of these three herbs act via similar mechanism and whether they possess comparable therapeutic efficacy for experimental myocardial ischemia (MI).

AIM OF THE STUDY

The present study aimed to further investigate the underlying mechanisms with respect to antioxidative stress activity by which these Dioscorea spp. attenuate MI, and to compare the therapeutic effect of total saponins from these three species on myocardial antioxidant levels and myocardial histology.

MATERIAL AND METHODS

The serum levels of creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), total superoxide dismutases (SOD), catalase (CAT), glutathione peroxidase (GPx), the total antioxidant capacity (T-AOC), and malondialdehyde (MDA), as well as myocardial histology, were compared among rat groups administered with total saponins (TS) of DN, DP or DZ (abbreviated as DNTS, DPTS and DZTS, respectively). The rats experienced myocardial ischemia induced by isoprenaline (ISO) injection; the test solutions (DNTS, DPTS, DZTS) were administered either after the ISO injection, or both before and after.

RESULTS

Compared with the model group (ISO injection only), TS groups exhibited significantly reduced activities of CK, LDH and AST, lowered level of MDA, and increased activities of SOD, CAT, GPx and T-AOC; heart tissues from TS groups revealed less severe histological damage. The cardioprotective efficacy of these three Dioscorea TS for rat MI was closely comparable based on the above observations.

CONCLUSION

The findings of the present study provide evidence that the anti-MI effect of DNTS, DPTS and DZTS can be attributed to the increase of myocardial antioxidant levels and decrease of lipid peroxidation formation, and the closely comparable results observed from these three Dioscorea saponins thereby explains the similarity in their clinical efficacy as anti-MI drugs.

Analysis of the Constituents in "Zhu She Yong Xue Shuan Tong" by Ultra High Performance Liquid Chromatography with Quadrupole Time-of-Flight Mass Spectrometry Combined with Preparative High Performance Liquid Chromatography

“Zhu She Yong Xue Shuan Tong” lyophilized powder (ZSYXST), consists of a series of saponins extracted from Panax notoginseng, which has been widely used in China for the treatment of strokes. In this study, an ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) combined with preparative high performance liquid chromatography (PHPLC) method was developed to rapidly identify both major and minor saponins in ZSYXST. Some high content components were removed through PHPLC in order to increase the sensitivity of the trace saponins. Then, specific characteristic fragment ions in both positive and negative mode were utilized to determine the types of aglycone, saccharide, as well as the saccharide chain linkages. As a result, 94 saponins, including 20 pairs of isomers and ten new compounds, which could represent higher than 98% components in ZSYXST, were identified or tentatively identified in commercial ZSYXST samples.

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.

Rapid separation and identification of 31 major saponins in Shizhu ginseng by ultra-high performance liquid chromatography-electron spray ionization-MS/MS

Background

Among the various ginseng strains, Shizhu ginseng is endemic to China, mainly distributed in Kuandian Manchu Autonomous County (Liaoning Province, China); however, not much is known about the compounds (especially saponins) in Shizhu ginseng.

Methods

A rapid, sensitive, and reliable ultra-high performance liquid chromatography coupled with MS/MS (UHPLC–MS/MS) method was developed to separate and identify saponins in Shizhu ginseng.

Results

The separation was carried out on a Waters ACQUITY UPLC BEH C₁₈ column (100 mm × 2.1 mm, 1.7 μm) with acetonitrile and 0.1% formic acid aqueous solution as the mobile phase under a gradient elution at 40°C. The detection was performed on a Micromass Quattro Micro API mass spectrometer equipped with electrospray ionization source in both positive and negative modes. Under the optimized conditions, a total of 31 saponins were identified or tentatively characterized by comparing retention time and MS data with related literatures and reference substances.

Conclusion

The developed UHPLC–MS/MS method was suitable for identifying and characterizing the chemical constituents in Shizhu ginseng, which provided a helpful chemical basis for further research on Shizhu ginseng.

UPLC-QTOF-MS identification of metabolites in rat biosamples after oral administration of Dioscorea saponins: a comparative study

ETHNOPHARMACOLOGICAL RELEVANCE

Among the 49 species of the genus Dioscorea distributed in China, Dioscorea nipponica Makino (DN), Dioscorea panthaica Prain et Burkill (DP), and Dioscorea zingiberensis C. H. Wright (DZ) possess more or less similar traditional therapeutic actions, such as activating blood, relieving pain, and dispersing swelling; they have been used as folk medicine in China since 1950s. The modern pharmaceutical industry has developed these three species as herbal medicines that have been used for decades for treating cardiovascular diseases. However, there is no available information in the literature explaining how their chemical components are converted and interrelated in vivo to support their efficacies. The present study aimed to a) compare the metabolic profiles of saponins from DN, DP and DZ, which are considered to be their bioactive components, and b) to compare the changes in sustained levels of metabolites from rat biosamples.

MATERIAL AND METHODS

Total saponins (TS) from each of the three species, and four individual saponins, namely protodioscin (PD), pseudoprotodioscin (PSD), dioscin (DC) and diosgenin (DG), were given to rats by oral administration. Chemical profiles of the rats' plasma, urine and feces were monitored 1-36 h. A UPLC-QTOF-MS based method was performed to identify the absorbed constituents and their metabolic products in rat biosamples (i.e., blood, urine, and feces); the ratio of peak area of major saponins to that of internal standard was calculated and plotted versus time to characterize the sustained levels of saponins in biosamples.

RESULTS

Totally 10 saponin-related compounds were detected in rat plasma, 10 in rat urine and 18 in rat feces. The results indicated that formation of diosgenin by desugarization was the main pathway by which steroidal glycosides were metabolized. Other types of bio-transformation were found among glycosides and aglycones, such as ring cyclization through loss of 26-O-glucosyl, substitution of β-D-glucopyranosyl for α-L-rhamnopyrannosyl, hydrogenation of diosgenin at 5(6)-double bond, and hydration of 20(22)-double bond. Generally, the metabolic profiles of DN and DP were shown to be quite similar, but different from that of DZ. However, some particular similarities and connections were found among these three TS. Diosgenin was one of the main metabolites commonly found in plasma and feces (excluding urine), from all groups receiving different TS, as well as individual saponins; this is likely to be one of the bioactive constituents playing an essential role in cardioprotective efficacy. Furostane-type saponins in TS of DN, DP or DZ, such as PD, protogracillin, parvifloside, protodeltonin and protobioside, showed fast absorption into blood (<1h), but were maintained for a relatively short period (mostly<8h), while the spirostane-type saponin and sapogenin (DC and DG, respectively), were absorbed into circulation more slowly (>1h), but increased gradually and lasted longer (>36h). These two patterns suggest that the therapeutic effect of these Dioscorea saponins is achieved through a complex, multi-step process over time. In addition, it appears that PD, PSD, and DC contained in DN and DP were transformed into certain glycosides originally found in DZ but not in DN or DP (protodeltonin, deltonin, trillin, and progenin II), which might indicate another linkage among these three species.

CONCLUSION

These similarities and connections described above constitute evidence supporting similarity in efficacy of these three herbs from the perspective of metabolism. The UPLC-QTOF-MS based method is accurate and efficient for analyzing metabolic changes in rat biosamples over time.

Ultrahigh-performance liquid chromatography-ion trap mass spectrometry characterization of the steroidal saponins of Dioscorea panthaica Prain et Burkill and its application for accelerating the isolation and structural elucidation of steroidal saponins

Dioscorea panthaica is a traditional Chinese medicinal herb used in the treatment of various physiological conditions, including cardiovascular disease, gastropathy and hypertension. Steroidal saponins (SS) are the main active ingredients of this herb and have effects on myocardial ischemia and cancer. The phytochemical evaluation of SS is both time-consuming and laborious, and the isolation and structural determination steps can be especially demanding. For this reason, the development of new methods to accelerate the processes involved in the identification, isolation and structural elucidation of SS is highly desirable. In this study, a new ultrahigh performance liquid chromatography-ion trap mass spectrometry (UHPLC-IT/MS(n)) method has been developed for the identification of the SS in D. panthaica Prain et Burkill. Notably, the current method can distinguish between spirostanol and furostanol-type compounds based on the fragmentation patterns observed by electrospray ionization-ion trap mass spectrometry (ESI-IT/MS(n)) analysis. UHPLC-IT/MS(n) was used to conduct a detailed investigation of the number, structural class and order of the sugar moieties in the sugar chains of the SS present in D. panthaica. The established fragmentation features were used to analyze the compounds found in the 65% ethanol fraction of the water extracts of D. panthaica. Twenty-three SS were identified, including 11 potential new compounds and six groups of isomers. Two of these newly identified SS were selected as representative examples, and their chemical structures were confirmed by (1)H and (13)C NMR analyses. This newly developed UHPLC-IT/MS(n) method therefore allowed for the efficient identification, isolation and structural determination of the SS in D. panthaica.

Determination of the triterpene glycosides in sea cucumbers by liquid chromatography with evaporative light scattering and mass spectrometry detection

Holothurian triterpene glycosides possess various kinds of biological activities, including antifungal, cytotoxic, hemolytic, cytostatic, and immunomodulatory effects. In this study, a rapid extraction method of triterpene glycosides from sea cucumbers using a small column of C18 solid phase was first developed. Furthermore, a novel high-performance liquid chromatography method coupled with evaporative light scattering detection and electrospray ionization mass spectrometry was established for the determination of each triterpene glycosides from different sea cucumbers. Simultaneous separation of all kind of triterpene glycoside were achieved on a C18 column. A gradient of aqueous acetonitrile was applied, and the method was validated. The liquid chromatography method was applied to the online mass detection to identify the triterpene glycosides in the purified extraction of eight kinds of pulverized sea cucumber from the market of Qingdao, China. The negative mode of [M-H](-)/[M-Na](-) exclusively shown signals corresponding to the triterpene glycosides previously reported and the MS(2) product ions of those ions indicate the specific structure of each triterpene glycoside.

Simultaneous quantification of five steroid saponins from Dioscorea zingiberensis C.H. Wright in rat plasma by HPLC-MS/MS and its application to the pharmacokinetic studies

A simple, reliable and sensitive high-performance liquid chromatography tandem mass spectrometry method (HPLC-MS/MS) was established for simultaneous analyses of the following 5 steroid saponins in rat plasma after the single dose administration of total steroid saponins extracted from the rhizome of Dioscorea zingiberensis C.H. Wright for the first time. Protodioscin, huangjiangsu A, zingiberensis new saponin, dioscin, and gracillin were quantified using ginsenoside Rb1 as the internal standard (IS). The plasma samples were pretreated by a single step acetonitrile-mediated protein precipitation. The chromatographic separation was performed on an Inersil ODS-3 C18 column (250mm×4.6mm, 5μm) with the mobile phase composed of acetonitrile and water containing 0.1% formic acid under a gradient elution mode at 0.2mLmin(-1) using a microsplit after the eluent from the HPLC apparatus. The quantification was accomplished on a triple quadrupole tandem mass spectrometer using the multiple reaction monitoring (MRM) in the positive ionization mode. The above five analytes were stable under sample storage and preparation conditions applied in the present study. The linearity, precision, accuracy, and recoveries of the analysis confirmed the requirements for quality-control purposes. After validation, this proposed method was successfully adopted to investigate the pharmacokinetic parameters of these five analytes.

Evaluation of different pretreatments on microbial transformation of saponins in Dioscorea zingiberensis for diosgenin production

In order to evaluate the effects of different pretreatments on microbial transformation of saponins in Dioscorea zingiberensis (DZW), various methods have been systematically studied on a large scale. Five pretreatments, including physical separation, catalytic solvent extraction, ultrasonic fermentation, complex enzymatic hydrolyzation and enzymatic saccharification, were performed on DZW. Compared with other methods, complex enzymatic hydrolyzation significantly improved the efficiency of microbial transformation. Due to the pretreatment, a diosgenin yield of 92.6%, and diosgenin accumulation of 27.3 mg/g DZW were achieved. The high efficiency of this method was attributed to the separation of 84.3% starch and 76.5% fibre from DZW in the form of a sugar. Analysis of saponins in this microbial transformation process showed that the residual rates of the intermediate products were much lower than those obtained from other pretreatments. The results demonstrate that complex enzymatic hydrolyzation is a practical and effective pretreatment method for production of diosgenin from DZW in a microbial transformation way.

Tandem mass spectrometric characterization of acetylated polyhydroxy hellebosaponins, the principal steroid saponins in Helleborus niger L. roots(#)

RATIONALE

Isolation and extensive nuclear magnetic resonance (NMR) analyses revealed polyhydroxy steroid saponins to be characteristic constituents in Helleborus niger L. roots. A comprehensive study including various multi-stage mass spectrometry (MS(n) ) experiments provided first solid chromatographic and mass spectrometric information facilitating future analysis and structural assessment of polyhydroxy saponins by LC/MS(n) techniques without isolation and NMR analyses.

METHODS

The polyhydroxy saponins were analyzed by direct syringe injection or chromatographically separated on a capillary high-performance liquid chromatography (HPLC) system coupled to an electrospray ionization (ESI) source. MS(n) spectra were recorded on an ion trap mass spectrometer including up to four fragmentation stages (LC/ESI-MS/MS). Additionally, high-resolution mass spectra were recorded on an Orbitrap Fourier transform (FT) mass spectrometer equipped with a nanospray-ESI interface.

RESULTS

The polyhydroxy hellebosaponins A and D were discovered to be significant constituents from H. niger roots. Extensive study of their MS(n) data revealed that they readily fragmented in the positive ion mode providing diagnostic fragments for elucidation of the steroidal character and number of OH groups. The negative ion mode yielded valuable information on the [M-H](-) ion, number and location of acetyl groups and sugar units. Additionally, fragmentation pathways for positive and negative ion modes were proposed.

CONCLUSIONS

These results not only extend the knowledge about H. niger saponins, but also provide a facilitated approach to the analysis of polyhydroxy saponins by LC/MS(n) without prior isolation and extensive NMR identification. Additionally, proposed fragmentation pathways for positive and negative ionization modes provide a solid complementary database for further, more detailed MS(n) studies.

RECENT ADVANCES IN ULTRA-HIGH PERFORMANCE LIQUID CHROMATOGRAPHY FOR THE ANALYSIS OF TRADITIONAL CHINESE MEDICINE

Traditional Chinese medicine has been widely used for the prevention and treatment of various diseases for thousands of years in China. Ultra-high performance liquid chromatography (UHPLC) is a relatively new technique offering new possibilities. This paper reviews recent developments in UHPLC in the separation and identification, fingerprinting, quantification, and metabolism of traditional Chinese medicine. Recently, the combination of UHPLC with MS has improved the efficiency of the analysis of these materials.

A Platform for Screening Potential Anticholinesterase Fractions and Components Obtained from Anemarrhena asphodeloides Bge for Treating Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive memory loss and cognitive impairment. Cholinesterase inhibitors are widely used for the symptomatic treatment of Alzheimer's disease to enhance central cholinergic transmission. In this study, a bioactivity-oriented screening platform based on a modified Ellman's method and HPLC-QTOF MS technique was developed to rapidly screen active agents of Anemarrhena asphodeloides Bge. The 60% ethanol fraction from an ethyl acetate extract exhibited the most potential anticholinesterase activity. Fifteen steroid saponins were identified by the mass spectrum, standards and literature reports. Twenty-five compounds were isolated from the active fraction. The results showed that compounds with the C₆–C₃–C₆ skeleton probably had both AChE and BuChE inhibitory activities. Xanthone and benzene derivatives exhibited no or little activity. Lignans showed weak BuChE inhibitory activity. The steroidal saponins demonstrated moderate or weak AChE inhibitory activity.

Simultaneous determination of 12 index components and compatibility changes in Longchai decoction by liquid chromatography-mass spectrometry

The aim of this study was to explore the traditional decoction theory of Chinese medicine compound prescriptions. To control the quality of Longchai decoction and to analyze the changes of chemical components before and after compatibility, the determination method of 12 index components including salidroside, wogonoside, liquiritin, isoliquiritin, liquiritigenin, quercetin, isoliquiritigenin, isorhamnetin, wogonin, saikosaponin A, saikosaponin D and ursolic acid by liquid chromatography-mass spectrometry (LC-MS) was established. The 12 index components were detected by LC-MS with the Agilent Zorbax SB C18 (3.1 × 100 mm, 3.6 µm) column, the mobile phase consisted of acetonitrile-0.1% methanoic acid with gradient elution at the flow rate of 0.25 mL min(-1) and the column temperature was maintained at 30°C. All the samples were isolated to baseline. All calibration curves showed good linear regression (r(2) > 0.9978). The average recoveries were between 99.16 and 103.25% of relative standard deviation <2.82% (n = 5). Obtained results indicated that the content of index components was increased in traditional decoction, compared with mixed individual decoctions. This method with good resolution and high precision could be used for the quality control of Longchai decoction.

Chemical fingerprint analysis and quantitative determination of steroidal compounds from Dioscorea villosa, Dioscorea species and dietary supplements using UHPLC-ELSD

Ultra high-performance liquid chromatography (UHPLC) with evaporative light scattering detection was used for the quantification of steroidal saponins and diosgenin from the rhizomes or tubers of various Dioscorea species and dietary supplements that were purported to contain Dioscorea. The analysis was performed on an Acquity UPLC™ system with an UPLC™ BEH Shield RP18 column using a gradient elution with water and acetonitrile. Owing to their low UV absorption, the steroidal saponins were observed by evaporative light scattering detection. The 12 compounds could be separated within 15 min using the developed UHPLC method with detection limits of 5-12 µg/mL with 2 μL injection volume. The analytical method was validated for linearity, repeatability, accuracy, limits of detection and limits of quantification. The relative standard deviations for intra- and inter-day experiments were <3.1%, and the recovery efficiency was 97-101%. The total content of standard compounds was found to be in the ranges 0.01-14.5% and 0.9-28.6 mg daily intake for dry plant materials and solid commercial preparations, respectively. UHPLC-mass spectrometry with a quadrupole mass analyzer and ESI source was used only for confirmation of the identity of the various saponins. The developed method is simple, rapid and especially suitable for quality control analysis of commercial products.

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.

Preparative isolation and purification of five steroid saponins from Dioscorea zingiberensis C.H.Wright by counter-current chromatography coupled with evaporative light scattering detector

A counter-current chromatography (CCC) method was successfully applied to separate and purify steroid saponins from the traditional Chinese medicine Dioscorea zingiberensis C.H.Wright for the first time. Ethyl acetate-n-butanol-methanol-water (4:1:2:4, v/v) was used as the two-phase solvent system, and evaporative light scattering detector (ELSD) was used as the detector in this method. The method separated in a single run the following five steroid saponins: 26-O-β-d-glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 26-triol-3-O-[β-d-glucopyranosyl-(1→3)-β-d-glucopyranol-(1→4)-α-l-rhamnopyranosyl-(1→2)]-β-d-glucopyranoside (Compound A); 26-O-β-d-glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 26-triol-3-O-[β-d-glucopyranosyl(1→3)-α-l-rhamnopyranosyl(1→2)]-β-d-glucopyranoside (Compound B); 26-O-β-d-glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 26-triol-3-O-[α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranoside (Compound C); 26-O-β-d-glucopyranosyl-(25R)-furost-5, 20(22)-diene-3β, 26-diol-3-O-{α-l-rhamnopyranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)-β-d-glucopyranosyl-(1→2)]}-β-d-glucopyranoside (Compound D); and 26-O-β-d-glucopyranosyl-(25R)-furost-5, 20(22)-diene-3β, 26-diol-3-O-[β-d-glucopyranosyl-(1→4)-α-l-rhamnopyranosyl(1→2)]-β-d-glucopyranoside (Compound E). Their structural identification of the five steroid saponins was performed by means of ESI-MS, and (13)C NMR.

Quantitative comparison of multiple components in Dioscorea nipponica and D. panthaica by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

INTRODUCTION

Dioscorea nipponica (DN) and D. panthaica (DP) have been uniquely prepared as herbal medicinal products for treating coronary heart disease (CHD) in China. However, so far there has been little discussion and no work comparing the qualitative and quantitative differences between the two herbs nor assessing whether they have similarities in chemical composition that would support their common application for treating CHD.

OBJECTIVE

To develop an efficient and reliable method based on UPLC-qTOF-MS for quantitative comparison of saponins in both DN and DP.

METHODS

Using electrospray ionisation and atmospheric-pressure chemical ionisation respectively, six steroidal glycosides and one aglycone were determined in 13 DN samples and 13 DP samples. The comparative analysis of chemical components in DN and DP was carried out by chromatographic fingerprint similarity evaluation, test of significance (t-test) and principle component analysis (PCA).

RESULTS

The UPLC-qTOF-MS method showed limit of detection and quantitation within the range 0.02-0.2 ng and 0.08-0.5 ng, respectively, for the seven saponins studied. The intra- and interday precision (RSD) were below 5%. The recoveries for the quantified compounds were within the range of 72.79-118.31%.

CONCLUSION

This UPLC-qTOF-MS assay provides a suitable method for the identification and determination of major bioactive constituents both in DN and DP. The chemical composition of all DN and DP samples studied exhibited a high level of global similarity. This chemical similarity validates their common application in the pharmaceutical industry as anti-CHD herbal drugs.

Characterization and identification of steroidal saponins from the seeds of Trigonella foenum-graecum by ultra high-performance liquid chromatography and hybrid time-of-flight mass spectrometry

Ultra high-performance liquid chromatography (UHPLC) coupled with hybrid quadrupole time-of-flight mass spectrometry (Qtof MS(E)) was used to rapidly separate and identify steroidal saponins from the crude extract of the seeds of Trigonella foenum-graecum (TFG). By using the UHPLC/Qtof MS(E) data acquisition strategy, both intact precursor and fragment ion information were obtained from a single injection. Fragmentation rules for five major groups of saponins from TFG are summarized, and possible fragmentation pathways are proposed. Accurate mass measurements of molecular ions and fragment ions as well as retention times permitted the identification or tentative identification of a total of ninety-five saponins based on comparison with reference standards. This included twenty-two pairs of isomers. Thirty of these saponins were identified for the first time.