In-depth investigation of the therapeutic effect of Tribulus terrestris L. on type 2 diabetes based on intestinal microbiota and feces metabolomics.

ETHNOPHARMACOLOGICAL RELEVANCE: The fruit of Tribulus terrestris L. (TT) is extensively documented in the Tibetan medical literature 'Si Bu Yi Dian', has been used to treat diabetes mellitus for more than a thousand years. However, the underlying mechanisms and comprehensive effects of TT on diabetes have yet to be investigated. AIM OF THE STUDY: The aim of the study was to systemically elucidate the potential mechanisms of TT in treating diabetes mellitus, and further investigate the therapeutic effects of the water extract, small molecular components and saccharides from TT. MATERIALS AND METHODS: Fecal metabolomics was employed to draw the metabolic profile based on UHPLC-Q-TOF-MS/MS. The V3-V4 hypervariable regions of the bacteria 16S rRNA gene were amplified to explore the structural changes of the intestinal microbiome after TT intervention and to analyze the differential microbiota. The microbial metabolites SCFAs were determined by GC-MS, and the BAs and tryptophan metabolites were quantified by UPLC-TQ-MS. Spearman correlation analysis was carried out to comprehensively investigate the relationship among the endogenous metabolites profile, intestinal microbiota and their metabolites. RESULTS: TT exhibited remarkably therapeutic effect on T2DM rats, as evidenced by improved glucolipid metabolism and intestinal barrier integrity, ameliorated inflammation and remission in insulin resistance. A total of 24 endogenous biomarkers were screened through fecal metabolomics studies, which were mainly related to tryptophan metabolism, fatty acid metabolism, bile acid metabolism, steroid hormone biosynthesis and arachidonic acid metabolism. Investigations on microbiomics revealed that TT significantly modulated 18 differential bacterial genera and reversed the disordered gut microbial in diabetes rats. Moreover, TT notably altered the content of gut microbiota metabolites, both in serum and fecal samples. Significant correlation among microbial community, metabolites and T2DM-related indicators was revealed. CONCLUSIONS: The multiple components of TT regulate the metabolic homeostasis of the organism and the balance of intestinal microbiota and its metabolites, which might mediate the anti-diabetic capacity of TT.

A novel strategy on the study of whole intestinal metabolic profiles for Polygalae Radix before and after processing.

INTRODUCTION: Relieving toxicity and enhancing a calming effect after processing Polygalae Radix (PR) are widely known. Aromatic carboxylic acids (ACAs) may be crucial processed products. However, due to the limited detection methods for ACAs, the whole metabolic profiles via intestinal bacteria are still not very clear. OBJECTIVE: Designing a novel strategy for the detection of ACAs and tracking the whole metabolic profiles before and after processing PR. MATERIALS AND METHODS: The stable-isotope labelling derivatisation (SILD) method based on multidimensional ultra-high performance liquid chromatography coupled with a mass spectrometer (UHPLC-MS) technology and UNIFI-pathway mode was firstly designed to systematically study the metabolisms of all the drug-derived ingredients ranging from m/z 100 to 2000 in processing PR via intestinal bacteria. Firstly, the SILD with UHPLC coupled with a triple-quadrupole MS technology was designed to trace eight ACA metabolites of the processed PR with intestinal bacteria. Additionally, the UHPLC coupled with a quadrupole time-of-flight MS with UNIFI-pathway mode was adopted to monitor relatively big metabolites. RESULTS: The metabolism mechanism of ACAs (eight kinds) and the relatively big molecular metabolites (98 kinds) were deeply traced in PR, PR with refined honey (HP), and PR with licorice (LP) via the intestinal bacteria. Totally 106 intact metabolic profiles of drug-derived ingredients were presented. Importantly, the influence of LP on the metabolism of compounds after incubation of intestinal bacteria was greater than that of HP. CONCLUSION: This research provides a comprehensive and systematic guidance for further study on in vivo metabolisms of the processed PR.

Ligand-targeted fishing of α-glucosidase inhibitors from Tribulus terrestris L. based on chitosan-functionalized multi-walled carbon nanotubes with immobilized α-glucosidase.

α-Glucosidase inhibitors in natural products are one of the promising drugs for the treatment of type 2 diabetes. However, due to the complexity of the matrix, it is challenging to comprehensibly clarify the specific pharmacodynamic substances. In this study, a novel high-throughput inhibitor screening strategy was established based on covalent binding of α-glucosidase on chitosan-functionalized multi-walled carbon nanotubes coupled with high-resolution mass spectrometry. The synthesized MWCNTs@CS@GA@α-Glu was characterized by TEM, SEM, FTIR, Raman, and TG. Performance studies showed that the microreactor exhibited stronger thermostability and pH tolerance than that of the free one while maintaining its inherent catalytic activity. Feasibility study applying a model mixture of known α-glucosidase ligand and non-ligands indicated the selectivity and specificity of the system. By integrating ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-QTOF-MS) with ion mobility mass spectrometry (IMS), 15 ligands were obtained and tentatively identified from Tribulus terrestris L., including 8 steroidal saponins, 4 flavonoids, and 3 alkaloids. These inhibitors were further validated by in vivo experiments and molecular docking simulation.

Treatment effects of Radix ginseng-Schisandra chinensis herb pair on Alzheimer's disease: An investigation of MS-based metabolomics investigation.

Traditional Chinese medicine (TCM) plays a synergistic and comprehensive pharmacodynamic role of multi-channel and multi-target through its multi-components, showing unique therapeutic advantages in chronic and multi-gene complex diseases. Herb pair is a unique combination of two relatively fixed herbs, which embodies the integrity of TCM theory. In this study, untargeted fecal metabolomics based on MS was used to investigate the action mechanism of Radix ginseng and Schisandra chinensis (GS) herb pair on the complex disease of Alzheimer's disease (AD), and further analyze the therapeutic effects of small molecular components and saccharides of GS on AD. Quantitative analysis of bile acids (BAs) and short-chain fatty acids (SCFAs) further verified the conclusion of untargeted metabolomics. The results of the pharmacodynamics evaluation showed that the AD model was successfully constructed, and each TCM group had a different degree of improvement compared with the AD group. PCA analysis based on untargeted fecal metabolomics showed that the metabolic disorders in AD rats changed significantly over time, and there were different degrees of callback in each TCM group. The result indicated that the GS herb pair can regulate metabolic disorders of AD. Further analysis of therapeutic biomarkers showed that GS mainly regulated the metabolism of bile acid biosynthesis, sphingolipid metabolism, porphyrin and chlorophyll metabolism, etc. to treat AD. This study will help to further understand the pathogenesis of AD from metabolomics, and provide beneficial support for the further study of GS and the clinical treatment of complex diseases with TCM.

Effect of Qishen granules on isoproterenol-induced chronic heart failure in rats evaluated by comprehensive metabolomics.

Qishen granules (QSG), a Chinese herbal formula, has been widely used in the treatment of myocardial ischemic chronic heart failure (CHF) for many years, but its mechanism of action is still unclear. In this study, comprehensive metabolomics was used to investigate the underlying protective mechanisms of QSG in an isoproterenol-induced CHF rat model. A total of 14 biomarkers were identified in serum and 34 biomarkers in urine, which were mainly related to fatty acid metabolism, bile acid metabolism, amino acid metabolism, purine metabolism, vitamin metabolism, and inflammation. Finally, 22 markers were selected for quantitative analysis of serum, urine, and fecal samples to verify the reliability of the results of untargeted metabolomics, and the results were similar to those of untargeted metabolomics. The correlation analysis showed that the targeted quantitative endogenous metabolites and CHF-related indexes were closely related. QSG might alleviate myocardial inflammatory response, oxidative stress, and amino acid metabolism disorder in CHF by regulating the level of endogenous metabolites. This study revealed QSG could regulate potential biomarkers and correlated metabolic pathway, which provided support for the further application of QSG.

A Strategy for Identification and Structural Characterization of Compounds from Plantago asiatica L. by Liquid Chromatography-Mass Spectrometry Combined with Ion Mobility Spectrometry.

Plantago asiatica L. (PAL) as a medicinal and edible plant is rich in chemical compounds, which makes the systematic and comprehensive characterization of its components challenging. In this study, an integrated strategy based on three-dimensional separation including AB-8 macroporous resin column chromatography, ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF MS), and ultra-high performance liquid chromatography-mass spectrometry with ion-mobility spectrometry (UHPLC-IM-MS) was established and used to separate and identify the structures of compounds from PAL. The extracts of PAL were firstly separated into three parts by AB-8 macroporous resin and further separated and identified by UHPLC-Q-TOF MS and UHPLC-IM-MS, respectively. Additionally, UHPLC-IM-MS was used to identify isomers and coeluting compounds, so that the product ions appearing at the same retention time (RT)can clearly distinguish where the parent ion belongs by their different drift times. UNIFI software was used for data processing and structure identification. A total of 86 compounds, including triterpenes, iridoids, phenylethanoid glycosides, guanidine derivatives, organic acids, and fatty acids, were identified by using MS information and fragment ion information provided by UHPLC-Q-TOF MS and UHPLC-IM-MS. In particular, a pair of isoforms of plantagoside from PAL were detected and identified by UHPLC-IM-MS combined with the theoretical calculation method for the first time. In conclusion, the AB-8 macroporous resin column chromatography can separate the main compounds of PAL and enrich the trace compounds. Combining UHPLC-IM-MS and UHPLC-Q-TOF MS can obtain not only more fragments but also their unique drift times and RT, which is more conducive to the identification of complex systems, especially isomers. This proposed strategy can provide an effective method to separate and identify chemical components, and distinguish isomers in the complex system of traditional Chinese medicine (TCM).

Comprehensive fecal metabolomics and gut microbiota for the evaluation of the mechanism of Panax Ginseng in the treatment of Qi-deficiency liver cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Qi deficiency liver cancer (QDLC) is an important part of liver cancer research in traditional Chinese medicine (TCM). In the course of its treatment, Panax ginseng is often selected as the main Chinese herbal medicine, and its function has special significance in the tumor treatment of Qi deficiency constitution. However, its mechanism is not clear. AIM OF THE STUDY: The research tried to evaluate the mechanism of Panax ginseng in the treatment of QDLC through fecal metabonomics and gut microbiota on the basis of previous pharmacodynamic evaluation. MATERIALS AND METHODS: Firstly, biomarkers and related metabolic pathways were screened and identified by metabonomics and Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Then, 16S rRNA sequencing technique was used to investigate the composition, ß diversity and key differences of gut microbiota. Finally, the relationship among phenotypes, gut microbiota and fecal metabolites was comprehensively analyzed by spearman correlation coefficient. RESULTS: 31 pharmacodynamic potential biomarkers and 20 synergistic potential biomarkers of effective parts of Panax ginseng on QDLC were screened and identified by fecal metabonomics. And then, 6 major metabolic pathways were searched, including bile acid biosynthesis, unsaturated fatty acid biosynthesis, tryptophan metabolism, arachidonic acid metabolism, pyrimidine metabolism, vitamin B6 metabolism. In the study of gut microbiota, at the genus level, 25 species of bacteria with significant differences of effective parts on QDLC and 23 species of bacteria with significant differences of synergistic action of ginsenosides and polysaccharides were screened. In addition, Spearman correlation analysis showed that there was a complex potential relationship among phenotype, gut microbiota and fecal metabolites during the development of QDLC and Panax ginseng intervention, which was mainly reflected in the close potential relationship between bacteria and fecal metabolites such as bile acids, unsaturated fatty acids and indole compounds. CONCLUSION: Through the changes of fecal endogenous metabolites and intestinal bacteria, the mechanism of Panax ginseng on QDLC were preliminarily clarified.

Pharmacokinetics and tissue distribution study of 18 bioactive components in healthy and chronic heart failure rats after oral administration of Qi-Shen-Ke-Li formula using ultra-high-performance liquid chromatography/triple quadrupole mass spectrometry.

RATIONALE: Qi-Shen-Ke-Li (QSKL) is a traditional Chinese formula used in clinical practice to treat chronic heart failure (CHF) in humans. To rationalize the use of this formula in clinical practice, the pharmacokinetics and tissue distribution in rats after oral administration of QSKL were investigated using ultra-high-performance liquid chromatography/triple quadrupole mass spectrometry (UHPLC/TQ-MS). METHODS: The CHF model was induced by intraperitoneal injection of isoprenaline (ISO; also known as isoproterenol) and evaluated by HE staining and brain natriuretic peptide (BNP) measurement. The UHPLC/TQ-MS method was then applied to determine the concentrations of 18 bioactive components in rat plasma and tissues of heathy and CHF rats after oral administration of QSKL. This was followed by investigating the pharmacokinetics and tissue distribution profiles of these bioactive compounds in the heathy and CHF rats. RESULTS: The pharmacokinetics results showed that the duration time of two compounds was prolonged, the absorption rate of four compounds was accelerated, and the bioavailability of four compounds was increased in the CHF rats compared with the healthy rats. Meanwhile, the tissue distribution results showed that the QSKL formula could be distributed rapidly and widely in different rat tissues. The bioavailability of eight compounds in the liver was enhanced in CHF rats. This suggested that the drug/toxic effects should be considered in clinical practice, as drug-drug interactions might occur in liver metabolism during the drug combination. CONCLUSIONS: The pharmacokinetic profiles and tissue distribution of 18 bioactive compounds in QSKL are altered by the CHF status. This study provides insight for better clinical applications of this formula in the future and lays the foundation for the development of a new drug for chronic heart failure based on the QSKL formula.

A metabolomic study of the urine of rats with Alzheimer's disease and the efficacy of Ding-Zhi-Xiao-Wan on the afflicted rats.

As a well-known traditional Chinese medicine formula, Ding-Zhi-Xiao-Wan has long been used for the routine treatment of Alzheimer's disease. However, the mechanism of Ding-Zhi-Xiao-Wan in treating Alzheimer's disease is unclear. Therefore, a nontargeted metabolomics method based on ultrahigh performance liquid chromatography with quadrupole time-of-flight mass spectrometry has been established to explore the metabolic variations in the urine of Alzheimer's disease rats and investigate the therapeutic mechanism of Ding-Zhi-Xiao-Wan on Alzheimer's disease. To develop a better rat model of Alzheimer's disease, amyloid ß25-35 was injected into the bilateral hippocampus of Sprague-Dawley rats. Multivariate analysis approaches were applied to differentiate the urine components between the four groups. Thereafter, a targeted metabolomics method was used to verify the identified endogenous metabolites and determine the mechanism of action of Ding-Zhi-Xiao-Wan. Altogether, 26 potential biomarkers were found, of which 15 biomarkers (10 of which are potential biomarkers found in nontargeted metabolomics) were identified. The results show that Ding-Zhi-Xiao-Wan mainly affects the pathways of taurine and hypotaurine metabolism, tryptophan metabolism, and phenylalanine metabolism. Ding-Zhi-Xiao-Wan might play a role in the treatment of Alzheimer's disease by mediating antioxidative stress, regulation of energy metabolism, improvement of intestinal microbes, and protection of nerve cells.

Chemical characterization of small-molecule inhibitors of monoamine oxidase B synthesized from the Acanthopanax senticosus root with affinity ultrafiltration mass spectrometry.

RATIONALE: Discovering and identifying new small-molecule inhibitors of monoamine oxidase B (MAO-B) could provide the potential to treat many neurodegenerative diseases. METHODS: We employed affinity ultrafiltration liquid chromatography/tandem mass spectrometry (AUF-LC/MSn ) to identify and characterize small-molecule inhibitors of MAO-B from a 30% ethanolic extract of Acanthopanax senticosus root (ASR). In vitro tests were performed in stimulated BV2 microglia to evaluate the anti-inflammatory effects of the ASR preparation. An in vitro enzyme activity assay, measuring half-maximal inhibitory concentrations (IC50 ) against MAO-B, determined the inhibitory activity of the potential MAO-B ligands. RESULTS: ASR treatment significantly inhibited NO release (p <0.01) and attenuated tumor necrosis factor (TNF)-α expression in stimulated BV2 microglia. Nine compounds were isolated from the ASR preparation as potential MAO-B inhibitors, identified as quinic acid, chlorogenic acid, isofraxidin, dicaffeoylquinic acid, pinoresinol diglucoside, medioresinol 4'-O-ß-D-glucopyranoside, eletutheroside E, syringaresinol O-ß-D-glucoside, and trihydroxyoctadecenoic acid, based on their tandem mass spectra. CONCLUSIONS: Our study provides critical data on compounds from ASR extracts which are suitable for the development of new MAO-B inhibitors as potential therapeutics for neurodegenerative diseases.

A target integration strategy for analyzing multidimensional chemical and metabolic substance groups of Ding-Zhi-Xiao-Wan prescription by using ultra-high performance liquid chromatography tandem mass spectrometry.

It is both challenging and meaningful for identifying the in vivo metabolites of the complex prescription owning to more complex chemical constituents and better therapeutic effect than those of the single medicine. In this paper, a target integration strategy combined with tandem mass spectrometry technology was developed for identification of metabolites from monomer composition of representative standard to Ding-Zhi-Xiao-Wan prescription (DZXW). The representative standards of each type in DZXW were utilized fully to explore the rule of mass fragmentation and the metabolism in vitro. These study were then extended to the single medicine and finally to the DZXW prescription. In addition, the order of metabolic research followed the metabolic order of oral drug in body, namely from in vitro, to intestine tract, to liver, to blood, and ultimately to target organs. As a result, a total of 150 prototypes and 51 metabolites of DZXW were effectively detected and identified in vivo. This result laid a material foundation for the better application of DZXW in treating Alzheimer's disease. More importantly, this analysis strategy provided a deep insight for the drug metabolism of traditional Chinese medicine.

Equivalently Quantitative Ion Strategy with Quaternary Ammonium Cation Derivatization for Highly Sensitive Quantification of Lanostane-Type Triterpene Acids without Standards by Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-MS/MS).

Lanostane-type triterpene acids are one of the main active components in Poria cocos, which have strong anticancer, immune regulation, antiaging, and anti-inflammation effects. However, low abundance, structure similarity, poor ionization efficiency, and especially the lack of adequate standards has hampered their accurate quantification. In this work, we develop an equivalently quantitative ion strategy with quaternary ammonium cation derivatization and established only one calibration curve for highly sensitive quantification of lanostane-type triterpene acids by ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in the absence of standards. Quaternary ammonium derivatives of all the lanostane-type triterpene acids generate two specific fragment ions of m/ z 130 and 170. Moreover, the signal intensity of the m/ z 170 fragment is positively correlated with the concentration of all derivatives under the optimal MS parameters, so this fragment is chosen as the equivalently quantitative ion to easily quantify derivatived lanostane-type triterpene acids. The concentration of derivatives and the signal intensity of m/ z 170 have a good linear relationship, with a correlation coefficient ( r2) of >0.999, and the good accuracy, precision, and high recovery guaranteed the reliability of lanostane-type triterpene acid derivative quantification. This derivatization method enables accurate quantitation of a total of 53 and 19 lanostane-type triterpene acids in the Poria cocos extracts and MDCK cell bidirectional transport samples with a limit of quantitation (LOQ) of 0.1 nM, respectively. This method also could be applied to quantitatively analyze the derivatives of the carboxyl compounds that have the same core structure with small differences in substituents.

Effect of type 2 diabetes mellitus on flavonoid pharmacokinetics and tissue distribution after oral administration of Radix Scutellaria extract in rats.

Radix Scutellaria is widely applied to the treatment of diabetes mellitus in China. Its main bioactive constituents contain baicalin, wogonoside, oroxyloside, and their aglycones. To investigate the effect of type 2 diabetes mellitus on both pharmacokinetics and tissue distribution of these flavonoid compounds, the six flavonoids in plasma and tissues from the normal and type 2 diabetic rats after oral administration of Radix Scutellaria extract were simultaneously measured by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. The results showed that baicalin, wogonoside, and oroxyloside had higher Cmax and AUC values (P < 0.05) in type 2 diabetic rats than that in normal rats and the tissue-distribution behaviors of the six flavonoid compounds in hearts, livers, spleens, lungs, kidneys, brains, pancreas, fat and muscle of the type 2 diabetic rats showed obviously differences from the normal rats (P < 0.05). In conclusion, the differences in the pharmacokinetics of oroxyloside and tissue distribution of the six flavanoids in Radix Scutellaria extract between diabetic and normal rats were found for the first time. The results from the present study provided a crucial basis for a better understanding of in vivo anti-diabetic mechanism of action of the six flavonoids from Radix Scutellaria.

Systematic study on metabolism and activity evaluation of Radix Scutellaria extract in rat plasma using UHPLC with quadrupole time-of-flight mass spectrometry and microdialysis intensity-fading mass spectrometry.

Radix Scutellaria is a widely used traditional Chinese medicine in the treatment of various diseases. However, the activities of the absorbed components and metabolites of its main flavones in rat plasma need further investigation. In this study, a systematic method based on ultra-high performance liquid chromatography with quadruple time-of-flight mass spectrometry was developed to speculate the absorbed components and metabolites of the main flavonoids in Radix Scutellaria extract in rat plasma sample after oral administration of the extract. Twelve compounds, including four prototype components and eight metabolites, were confirmed in drug-containing plasma. In these metabolites, five were originally detected in rat plasma. The possible metabolic pathways of these polyhydroxy flavones in vivo were described and clarified. Microdialysis with intensity-fading mass spectrometry was originally employed to investigate the binding affinities of the absorbed components and metabolites with α-glucosidase. The order of their binding affinities was P4 > P3 > P2 > P1≥M5 > M3 > M1. The research result is helpful to deepen the understanding of the absorbed components and metabolic pathways of main flavones from Radix Scutellaria, and provide a new approach to screen potential inhibitors from in vivo components originated from Chinese herb.

Characterization of interaction property of multi-components in Gardenia jasminoides with aldose reductase by microdialysis combined with liquid chromatography coupled to mass spectrometry.

RATIONALE: An application of microdialysis sampling for evaluation of the interaction property of small molecules to macromolecules is presented. Microdialysis combined with liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry (LC/QTOF-MS/MS) was established for the purpose of screening of the multiple bioactive compounds in traditional Chinese medicines (TCMs). METHODS: Microdialysis experiments were performed in vitro using a syringe pump and probes. Separation was achieved via liquid chromatography, and MS analysis was conducted by electrospray ionization quadrupole time-of-flight mass spectrometry in negative mode. The interaction property of compounds in TCMs with aldose reductase can be deduced from the comparison of the peak areas in chromatograms using a stable internal standard. RESULTS: In this work, 23 compounds including iridoids, flavonoids, monoterpenoids, carotenoids and phenolic acids were identified by comparison with reference compounds, characteristic high-resolution mass spectrometry and the MS/MS fragmentations simultaneously. Binding degrees of 23 compounds in Gardenia jasminoides Eliis (G. jasminoide) with aldose reductase ranged from 13.91% to 66.25%. Also, microdialysis recoveries of 23 compounds in G. jasminoides were determined. CONCLUSIONS: The Interaction properties of 23 compounds in G. jasminoides with aldose reductase were investigated and they are potential bioactive ingredients. Microdialysis coupled to LC/QTOF-MS/MS can be used for screening of bioactive multicomponents from TCMs with appropriate targets. Copyright © 2016 John Wiley & Sons, Ltd.

A strategy for identification and structural characterization of compounds from Gardenia jasminoides by integrating macroporous resin column chromatography and liquid chromatography-tandem mass spectrometry combined with ion-mobility spectrometry.

In this paper, an analysis strategy integrating macroporous resin (AB-8) column chromatography and high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) combined with ion mobility spectrometry (IMS) was proposed and applied for identification and structural characterization of compounds from the fruits of Gardenia jasminoides. The extracts of G. jasminoides were separated by AB-8 resin column chromatography combined with reversed phase liquid chromatography (C18 column) and detected by electrospray ionization tandem mass spectrometry. Additionally, ion mobility spectrometry (IMS) was employed as a supplementary separation technique to discover previously undetected isomers from the fruits of G. jasminoides. A total of 71 compounds, including iridoids, flavonoids, triterpenes, monoterpenoids, carotenoids and phenolic acids were identified by the characteristic high resolution mass spectrometry and the ESI-MS/MS fragmentations. In conclusion, the IMS-MS technique achieved the separation of isomers in crocin-3 and crocin-4 according to their acquired mobility drift times differing from classical analysis by mass spectrometry. The proposed strategy can be used as a highly sensitive and efficient procedure for identification and separation isomeric components in extracts of herbal medicines.

Application of porous metal enrichment probe sampling to single cell analysis using matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS).

There is an increasing need for analyzing metabolism in a single cell, which is important to understand the nature of cellular heterogeneity, disease, growth and specialization, etc. However, single cell analysis is often challenging for the traces of samples. In the present study, porous metal enrichment probe sampling combined with matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) has been applied for in situ analysis of live onion epidemic cell. Porous probe, treated by corroding copper wire with HCl, was directly inserted into a single cell to get cell solution. A self-made linear actuator was enough to control the penetration of probe into the target cell accurately. Then samples on the tip of probe were eluted and detected by a commercial MALDI-TOF-MS directly. The formation of porous microstructure on the probe surface increased the adsorptive capacity of cell solution. The sensitivity of porous probe sampling was 6 times higher than uncorroded probes generally. This method provides a sensitive and convenient way for the sampling and detection of single cell solution. Copyright © 2015 John Wiley & Sons, Ltd.

Study of the non-covalent interactions of ginsenosides and lysozyme using electrospray ionization mass spectrometry.

RATIONALE: Ginsenosides are an important class of natural products extracted from ginseng that possess various important biological activities. Studies of interactions of ginsenosides with proteins are essential for comprehensive understanding of the biological activities of ginsenosides. In this study, the interactions of ginsenosides with lysozyme were investigated by electrospray ionization mass spectrometry (ESI-MS). METHODS: Both protopanaxadiol-type and protopanaxatriol-type ginsenosides were chosen to explore the interactions of ginsenosides towards lysozyme near the physiological conditions by direct ESI-MS, respectively. Comparative experiments were conducted to confirm the interactions were specific. In addition, the dissociation constants of ginsenoside-lysozyme complexes were determined by a ESI-MS titration strategy. RESULTS: The results showed ginsenosides bound to lysozyme at the stoichiometries of 1:1 and 2:1. The association constants of ginsenosides to lysozyme were in the order of Re>Rd>Rf>Rg2 >Rg3 . According to their structures, the binding affinities associated with the type of aglycone and the type and the number of sugar moieties linked on the aglycone. CONCLUSIONS: It has been demonstrated that ESI-MS is a powerful tool to probe the non-covalent interactions between lysozyme and ginsenosides. These results provide insights into the interaction of ginsenosides with lysozyme at the molecular level. The developed strategy could be applied to determine the interactions of proteins with other natural products.

Study of the ESI and APCI interfaces for the UPLC-MS/MS analysis of pesticides in traditional Chinese herbal medicine.

In this work, 53 selected pesticides of different chemical groups were extracted from Chinese herbal medicines and determined by ultra-high-performance liquid chromatography (UHPLC)-tandem mass spectrometry (MS/MS) using both electrospray ionization (ESI) and atmospheric-pressure chemical ionization (APCI). Extracts were obtained using the acetonitrile-based quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation technique. Cleanup was performed by dispersive solid-phase extraction using primary secondary amine, graphitized carbon black, and octadecylsilane. Two atmospheric-pressure interfaces, ESI and APCI, were checked and compared. The validation study, including detection limits, linearity, and matrix effects, was conducted on fritillaria, radix ginseng, folium isatidis, semen persicae, and flos lonicerae in multiple reaction monitoring mode. These matrices represent a variety of plants used in traditional Chinese medicine. Fritillaria and radix ginseng were chosen as representatives for roots, folium isatidis was chosen as a representative for leaves, semen persicae was chosen as a representative for seeds, and flos lonicerae was chosen as a representative for flowers. The limits of detection for pesticides were lower in the UHPLC-ESI-MS/MS method than in the UHPLC-APCI-MS/MS method. Matrix effects on the two ionizations were evaluated for the five matrices. Soft signal enhancement in UHPLC-APCI-MS/MS and signal suppression in UHPLC-ESI-MS/MS were observed.

[Effects of six kinds of Chinese herb extracts on the activities of rat liver microsomes in vitro].

Effects of six kinds of Chinese herb extracts, including Folium Crataegi extract, Herba Epimedii extract, Folium Acanthopanacis Senticosi extract, Trifolium pratense L. extract, Folium Ginkgo extract and Radix Puerariae extract, on the activities of CYP450 isozymes (CYP1A2, CYP2C, CYP2E1, CYP2D, CYP3A) in rat hepatic microsomals were studied by using a UPLC-MS/MS (MRM) and cocktail probe substrates method. The results showed that effects of six kinds of Chinese herb extracts on each CYP450 isozyme activity were inhibitory. The IC50 of Folium Crataegi extract for the inhibition of rat microsomal CYP2D activity was only for 4.04 microg x mL(-1), which showed the highest inhibition; Trifolium pratense L. extract had strong inhibitory action to CYP2D, the IC50 value was 5.73 microg x mL(-1); Folium Crataegi extract also had strong inhibitory action on CYP2E1, the IC50 value was 10.91 microg x mL(-1). Furthermore, the IC50 of Folium Ginkgo extract for the inhibition of rat microsomal CYP3A, 2D, 2E1 activities were 45.12, 35.45 and 22.41 microg x mL(-1), respectively, and the IC50 of Folium Acanthopanacis Senticosi extract on the inhibition of rat microsomal CYP2E1 activity was 32.89 microg x mL(-1). In addition, mechanism of inhibition experimental results showed that the inhibiting abilities of Folium Crataegi extract and Radix Puerariae extract on each CYP450 isozyme increased with the increasing of the preincubation time, therefore, the inhibitory effects were a mechanism-based inhibition.