Characterization of steroidal saponins from Dioscorea villosa and D. cayenensis using ultrahigh performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry

A high-permeability method for extracting purple yam saponins based on ultrasonic-assisted natural deep eutectic solvent

The extraction of active ingredients from traditional Chinese medicine has received considerable attentions. In this study, 16 kinds of natural deep eutectic solvent (NADES) with ultrasonic were selected to extract saponins from purple yam root and the extraction mechanism was investigated. The results showed that chloride/acrylic acid (1:2; n/n) had the highest extraction yield for saponins. The optimal extraction process parameters were 24% water content, 20 mL/g liquid-solid ratio, and ultrasonic extraction for 85 min (81 °C, 600 W). The extraction rate (ER) of purple yam saponins was 0.935%, close to the fitted result of 96.5 mg/g. Molecular dynamics simulations and FT-IR results showed that the NADES may extract the saponin constituents from purple yam through hydrogen bonding. Compared with traditional extraction methods and molecularly imprinted polymer methods, NADES has a higher ER and lower cost (1.53 $/g), which provides a reference for subsequent industrial quantitative production.

Phytochemical profiling of Livistona carinensis leaf extract via UHPLC-QTOF-MS/MS with assessment of its antiviral mechanisms

Among 36 species of the genus Livistona (family Palmae or Arecaceae), L. carinensis is considered the only species native to Africa. Previous studies showed the richness of Livistona fruits in phenolic compounds. The goal of the current study was to investigate the phytochemical composition and assess the antiviral mechanisms of the L. carinensis leaves' ethanolic extract cultivated in Egypt for the first time. The ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS/MS) was applied. Moreover, the total crude extract was fractionated using ethyl acetate and n-butanol for phytochemical investigations by various chromatographic and spectroscopic techniques. Besides, the antiviral activity of L. carinensis leaves was assessed using three protocols in vitro using MTT assay compared to acyclovir. UHPLC-QTOF-MS/MS-based analysis resulted in identification of 72 metabolites tentatively. They belonged to diverse phytochemical classes, mainly including flavonoids (29), organic acids (10), and phenolic acids (7). The antiviral activity investigations revealed a direct Adeno virus inactivation mechanism rather than inhibition of virus replication or blocking its attachment to Vero cells. Hence, the plant leaves may be a potential candidate for discovery of novel antiviral drugs owing to the diversity of identified phytochemical classes.

Isolation of two steroidal saponins with antileishmanial activity from Allium giganteum L

Background and purpose

Alliums are rich sources of steroidal saponins, flavonoids, and sulphoric compounds of which steroidal saponins have recently received more attention due to their important pharmacological activities. Allium giganteum (giant onion) which is named locally "Couria" in the Northeast of Iran, is grown widely in "Kouh-Sorkh" mountains in Khorasan province.

Experimental approach

Phytochemical investigation of chloroform-methanol and aqueous extract of the plant resulted in the isolation and identification of two steroidal saponins, using comprehensive spectroscopic methods including 1D and 2D NMR and MS.

Findings/Results

The chemical structures of the isolated saponins were determined as (22S)-cholesta-1b,3b,16b,22b-tetraol 5-en, and 3-O-β-D-glucopyranosyl26-O-β-D-glucopyranosside and (25R)-26-O-β-D-glucopyranosyl-5α-furostan-1α,3β,22α,26-tetraol3-O-{β-D-galactopyranosyl-(1→2)-O-[β-D-xylopyranosyl- (1→3)]-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside}. Investigation of in vitro antileishmanial activity of the isolated compounds at 10, 50, and 100 μg/mL exhibited significant leishmanicidal against the promastigotes of Leishmania major.

Conclusion and implications

The results established a valuable basis for further studies about A. giganteum and the anti-parasitic activity of steroidal saponins.

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.

Chemical Profiling and Characterization of Anthraquinones from two Bulbine species and Dietary Supplements Using Liquid Chromatography-High Resolution Mass Spectrometry

BACKGROUND

Bulbine natalensis Baker and Bulbine frutescens (L.) Willd. belonging to the family Asphodelaceae are widely distributed in South Africa and traditionally used as an aphrodisiac and skin remedies.

OBJECTIVE

The aim of this study is to develop an analytical method for chemical profiling and identification of components in Bulbine species, which would be useful for herbal identification and understanding of the biological activity of B. natalensis in terms of safety and benefits to human health.

METHODS

The anthraquinone-type of compounds were structurally characterized from the extracts of dried stem and roots of Bulbine species and dietary supplements using liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QToF) with negative and positive ion electrospray. The calculated accurate masses of the protonated and deprotonated molecules and fragment ions, were used for identification of the components from two Bulbine species.

RESULTS

A total of fifty-five anthraquinone-type compounds, including eleven standard compounds were identified in the crude extracts of two Bulbine species. Two Bulbine species and dietary supplements were clustered into different groups and possible chemical markers were identified.

CONCLUSION

The developed analytical method provided a fast, economic method for quality assessment of Bulbine species in dietary supplements based on anthraquinone-type compounds.

HIGHLIGHTS

This study reports holistic chemical profiling of Bulbine species using LC- QToF. The analytical method developed enabled non-targeted analysis of components in B. natalensis and B. frutescens, recommending for commercial and regulatory purposes.

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.

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.

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.

The anticancer potential of steroidal saponin, dioscin, isolated from wild yam (Dioscorea villosa) root extract in invasive human breast cancer cell line MDA-MB-231 in vitro

Previously, we observed that wild yam (Dioscorea villosa) root extract (WYRE) was able to activate GATA3 in human breast cancer cells targeting epigenome. This study aimed to find out if dioscin (DS), a bioactive compound of WYRE, can modulate GATA3 functions and cellular invasion in human breast cancer cells. MCF-7 and MDA-MB-231 cells were treated in the absence/presence of various concentrations of DS and subjected to gene analysis by RT-qPCR, immunoblotting, and immunocytochemistry. We determined the ability of MDA-MB-231 cells to migrate into wound area and examined the effects of DS on cellular invasion using invasion assay. DS reduced cell viability of both cell lines in a concentration and time-dependent manner. GATA3 expression was enhanced by DS (5.76 μM) in MDA-MB-231 cells. DS (5.76 μM)-treated MDA-MB-231 cells exhibited the morphological characteristic of epithelial-like cells; mRNA expression of DNMT3A, TET2, TET3, ZFPM2 and E-cad were increased while TET1, VIM and MMP9 were decreased. Cellular invasion of MDA-MB-231 was reduced by 65 ± 5% in the presence of 5.76 μM DS. Our data suggested that DS-mediated pathway could promote GATA3 expression at transcription and translation levels. We propose that DS has potential to be used as an anti-invasive agent in breast cancer.

Evaluation of wild yam (Dioscorea villosa) root extract as a potential epigenetic agent in breast cancer cells

The present study was designed to evaluate the efficacy of wild yam root extract (WYRE) as a potential demethylating agent using two breast cancer cell lines, MCF-7 (estrogen receptor positive; ER(+)) and MDA-MB-231 (Estrogen receptor negative; ER(-)), and a methylated gene, GATA3, as a potential marker of breast cancer development. The cells were treated with WYRE (0-50 μg/mL) for 72 h and used for viability, mRNA, and methylation analyses. WYRE significantly reduced viability of both cell lines and enhanced mRNA content of GATA3 in a concentration-dependent manner; however, DNMT mRNAs (DNMT1, 3A, 3B) were found to increase significantly only in MDA-MB-231 cells. Global DNA methylation, analyzed as 5'-methyl-2'-deoxycytidine (5-mC) and 5-hydroxymethylcytosine (5-hmC), showed a concentration-dependent enhancement of 5-mC with no alteration in 5-hmC level in MCF-7 cells; however, in MDA-MB-231 cells, in contrast to MCF-7 cells, 5-mC remained unaltered but 5-hmC reduced significantly in all WYRE concentrations (10-50 μg/mL) used in this study. Since 5-hmC is generated from 5-mC by ten-eleven-translocation (TET) enzymes, analysis of TET mRNAs (TET1, TET2, and TET3) in MDA-MB-231 cells indicated a concentration-dependent reduction in TET1 and induction of TET3; however, TET2 remained unaltered. No alterations in any of the TET mRNAs were found in MCF-7 cells. Methylation analysis of GATA3 promoter at specific locus indicates probable demethylating activity of WYRE in MDA-MB-231 cells. We conclude that activation of GATA3 gene in ER(-) MDA-MB-231 cells may occur by altering DNA methylation pattern on the promoter region which may be different from the mechanisms operated in ER(+) MCF-7 cells.