trap-Orbitrap Tandem Mass Spectrometry Research Articles

Peptide-Bound Glycative, AGE and Oxidative Modifications as Biomarkers for the Diagnosis of Alzheimer's Disease-A Feasibility Study.

Background: The diagnosis of Alzheimer's disease (AD) relies on core cerebrospinal fluid (CSF) biomarkers, amyloid beta (Aβ) and tau. As the brain is then already damaged, researchers still strive to discover earlier biomarkers of disease onset and the progression of AD. Glycation, advanced glycation end products (AGEs) and oxidative modifications on proteins in CSF mirror the underlying biological mechanisms that contribute to early AD pathology. However, analyzing free AGEs in the body fluids of AD patients has led to controversial results. Thus, this pilot study aimed to test the feasibility of detecting, identifying and quantifying differentially glycated, AGE or oxidatively modified peptides in CSF proteins of AD patients (n = 5) compared to a control group (n = 5). Methods: To this end, we utilized a data-dependent (DDA) nano liquid chromatography (LC) linear ion trap-Orbitrap tandem mass spectrometry (MS/MS) ) approach and database search that included over 30 glycative and oxidative modifications in four search nodes to analyze endogenous modifications on individual peptides. Furthermore, we quantified candidate peptide abundance using LC Quan. Results: We identified 299 sites of early and advanced glycation and 53 sites of oxidatively modified tryptophan. From those, we identified 17 promising candidates as putative biomarkers (receiver operating curve-area under the curve (ROC-AUC) > 0.8), albeit without statistical significance. Conclusions: The potential candidates with higher discrimination power showed correlations with established diagnostic markers, thus hinting toward the potential of those peptides as biomarkers.

Investigating the mechanism of cornel iridoid glycosides on type 2 diabetes mellitus using serum and urine metabolites in rats

Ethnopharmacological relevanceCornel iridoid glycosides (CIG) are extracted from Corni fructus, a herbal medicine used in traditional Chinese medicine to treat diabetes. However, the antidiabetic effects of CIG and the underlying metabolic mechanisms require further exploration. Aim of the studyThis study aimed to assess the antidiabetic effects and metabolic mechanism of CIG by performing metabolomic analyses of serum and urine samples of rats. Materials and methodsA rat model of type 2 diabetes mellitus (T2DM) was established by administering a low dose of streptozotocin (30 mg/kg) intraperitoneally after 4 weeks of feeding a high-fat diet. The model was evaluated based on several parameters, including fasting blood glucose (FBG), random blood glucose (RBG), urine volume, liver index, body weight, histopathological sections, and serum biochemical parameters. Subsequently, serum and urine metabolomics were analyzed using ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS). Data were analyzed using unsupervised principal component analysis (PCA) and supervised orthogonal partial least squares discriminant analysis (OPLS-DA). Differential metabolites were examined by the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways to explore the underlying mechanisms. ResultsAfter 4 weeks of treatment with different doses of CIG, varying degrees of antidiabetic effects were observed, along with reduced liver and pancreatic injury, and improved oxidative stress levels. Compared with the T2DM group, 19 and 23 differential metabolites were detected in the serum and urine of the CIG treatment group, respectively. The key metabolites involved in pathway regulation include taurine, chenodeoxycholic acid, glycocholic acid, and L-tyrosine in the serum and glycine, hippuric acid, phenylacetylglycine, citric acid, and D-glucuronic acid in the urine, which are related to lipid, amino acid, energy, and carbohydrate metabolism. ConclusionsThis study confirmed the antidiabetic effects of CIG and revealed that CIG effectively controlled metabolic disorders in T2DM rats. This seems to be meaningful for the clinical application of CIG, and can benefit further studies on CIG mechanism.

Kuntai capsule attenuates premature ovarian insufficiency by activating the FOXO3/SIRT5 signaling pathway in mice: A comprehensive study using UHPLC-LTQ-Orbitrap and integrated pharmacology

Ethnopharmacological relevanceClassical prescriptions are not only a primary method of clinical treatment in traditional Chinese medicine (TCM) but also represent breakthroughs in the inheritance and development of this field. Kuntai capsule (KTC), a formulation based on a classical prescription, comprises six TCMs: Rehmanniae Radix Praeparata, Coptidis Rhizoma, Paeoniae Radix Alba, Scutellariae Radix, Asini Corii Colla, and Poria. This formulation possesses various beneficial effects, such as nourishing yin and blood, clearing heat and purging fire, and calming the nerves and relieving annoyance. The investigation of the efficacy and mechanism of KTC in regulating anti-aging factors in the treatment of premature ovarian insufficiency (POI) is not only a prominent topic in classical prescription research but also a crucial issue in the treatment of female reproductive aging using TCM. Aim of the studyTo evaluate the therapeutic effect of KTC on POI and its underlying mechanism. Materials and methodsHealthy and specific pathogen-free (SPF) female Kunming mice aged 6–8 weeks were selected. After acclimatization, the mice were randomly divided into a control, model, and high, middle, and low dose groups of KTC (1.6, 0.8, and 0.4 mg/kg, respectively). Except for the control group, the animals in the other groups were administered a single intraperitoneal injection of 120 mg/kg cyclophosphamide and 30 mg/kg Busulfan to induce the model of POI. After modeling, the mice were treated with the corresponding drugs for 7 days. Serum and ovarian tissues were collected, and the levels of serum follicle-stimulating hormone (FSH), estradiol (E2), and superoxide dismutase 2 (SOD2) were determined using enzyme-linked immunosorbent assay (ELISA). The chemical composition of KTC was characterized and analyzed using ultra-high-pressure liquid chromatography-linear ion trap-Orbitrap tandem mass spectrometry. A “drug-component-target-pathway-disease” network was constructed using network pharmacology research methods to identify the key active components of KTC in treating POI and to elucidate its potential mechanism. The protein expression of the FOXO3/SIRT5 pathway was detected by western blotting. ResultsCompared to the model group, the high-dose group of KTC showed a significant increase in ovarian index, significant increase in levels of E2 and SOD2, and a significant decrease in FSH levels. Through systematic analysis of the chemical constituents of KTC, 69 compounds were identified, including 7 organic acids, 14 alkaloids, 28 flavonoids, 15 terpenoids, 2 lignans, 2 phenylpropanoids, and 1 sugar. Based on network pharmacology research methods, it was determined that KTC exerts its therapeutic effect on POI through multiple components (paeoniflorin and malic acid), multiple targets (FOXO3 and SIRT5), and multiple pathways (prolactin signaling pathway, longevity regulating pathway, and metabolic pathways). The accuracy of the network pharmacology prediction was further validated by detecting the protein expression of SIRT5 and FOXO3a, which showed a significant increase in the middle and high-dose groups of KTC compared to the model group. ConclusionsKTC may effectively treat POI through a multi-component, multi-target, multi-pathway approach, providing an experimental basis for using KTC based on classical prescriptions in the treatment of POI.

Polyphenol Content of Green Pea (Pisum sativum L.) Hull under In Vitro Digestion and Effects of Digestive Products on Anti-Inflammatory Activity and Intestinal Barrier in the Caco-2/Raw264.7 Coculture Model.

Green pea hulls are a byproduct of the processing of green pea and are rich in phenolic substances. In the present study, in vitro digestion, human colonic adenocarcinoma cell line (Caco-2) monolayer, and the Caco-2/macrophage cell lines of the murine origin (Raw264.7) coculture model were established to investigate the release of polyphenols, absorption, and transport of digestive products and their effects on inflammation and intestinal barrier. During the digestive process, polyphenols were constantly released from the pea hulls, reaching the maximum amount in the small intestine (total phenolic content (TPC): 5.41 ± 0.04 mg gallic acid (GAE)/g dry weight (DW)), and the digestive products (800 μg/mL) could reduce the secretion of NO (50.9%), IL-6 (50.6%), and TNF-α (24.6%) and inhibit the mRNA expression of cyclooxygenase-2 (COX-2) (37.2%) and inducible nitric oxide synthase (iNOS) (91.1%) compared with the lipopolysaccharide (LPS) group. A total of 12 phenolic components were quantified by ultraperformance liquid chromatography-linear ion trap orbitrap tandem mass spectrometry (UHPLC-LTQ-OrbiTrap-MS) technology. Kaempferol trihexoside in digestive products could be absorbed and transported (1.25 ± 0.13 ng quercetin/mL). The digestive products could promote the expression of claudin-1 (210.8%), occludin (64.9%), and zonulin occludin-1 (ZO-1) (52.0%) compared with the LPS group and exert anti-inflammatory effects after being absorbed. The results indicated that pea hull polyphenols could be continuously released and absorbed to play a positive role in protecting the intestinal barrier and anti-inflammatory activity.

Green Pea (Pisum sativum L.) Hull Polyphenol Extracts Ameliorate DSS-Induced Colitis through Keap1/Nrf2 Pathway and Gut Microbiota Modulation.

As a processing by-product, green pea hull (GPH) was found to be rich in phenolic components in our previous studies. In this study, UHPLC-LTQ-OrbiTrap-MS (Ultra performance liquid chromatography-linear ion trap orbitrap tandem mass spectrometry) technique was used to quantify polyphenols, and DSS (sodium dextran sulfate)-induced colitis mouse model was established to explore the effect of GPH extracts on colitis. The results showed that quercetin and its derivatives, kaempferol trihexanside and catechin and its derivatives were the main phenolic substances in the extract, reaching 2836.57, 1482.00 and 1339.91 µg quercetin/g GPH extract, respectively; GPH extracts can improved inflammatory status, repaired colonic function, regulated inflammatory factors, and restored oxidative balance in mice. Further, GPH extracts can activate Keap1-Nrf2-ARE signaling pathway, regulate downstream antioxidant protease and gut microbiota by increasing F/B value and promoting the growth of Lactobacillaceae and Lachnospiraceae, and improve the level of SCFAs (short-chain fatty acids) to relieve DSS-induced colitis in mice. Therefore, GPH may be a promising dietary resource for the treatment of ulcerative colitis.

The Tannins from Sanguisorba officinalis L. (Rosaceae): A Systematic Study on the Metabolites of Rats Based on HPLC-LTQ-Orbitrap MS2 Analysis.

Sanguisorba tannins are the major active ingredients in Sanguisorba ofJicinalis L. (Rosaceae), one of the most popular herbal medicines in China, is widely prescribed for hemostasis. In this study, three kinds of tannins extract from Sanguisorba officinalis L. (Rosaceae), and the metabolites in vivo and in vitro were detected and identified by high-pressure liquid chromatography, coupled with linear ion trap orbitrap tandem mass spectrometry (HPLC–LTQ–Orbitrap). For in vivo assessment, the rats were administered at a single dose of 150 mg/kg, after which 12 metabolites were found in urine, 6 metabolites were found in feces, and 8 metabolites were found in bile, while metabolites were barely found in plasma and tissues. For in vitro assessment, 100 μM Sanguisorba tannins were incubated with rat liver microsomes, liver cytosol, and feces, after which nine metabolites were found in intestinal microbiota and five metabolites were found in liver microsomes and liver cytosol. Moreover, the metabolic pathways of Sanguisorba tannins were proposed, which shed light on their mechanism.

Integrated Systems Pharmacology and Surface Plasmon Resonance Approaches to Reveal the Synergistic Effect of Multiple Components of Gu-Ben-Ke-Chuan Decoction on Chronic Bronchitis

IntroductionGu-Ben-Ke-Chuan (GBKC) decoction, a well-known prescription composed of seven herbs, has been widely used for treating chronic bronchitis (CB). However, the pharmacological constituents of GBKC and the underlying mechanisms by which these components act on CB remain unclear.MethodsUltra-high-pressure liquid chromatography coupled with linear ion trap–Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap) was first employed to rapidly identify compounds from GBKC. Thereafter, network pharmacology and molecular docking analyses were performed to identify the potential active constituents, candidate targets, and major pathways. Finally, the affinities between the key compounds and targets were verified via surface plasmon resonance (SPR) analysis. In addition, the anti-inflammatory effect of GBKC was verified using an LPS-induced inflammatory cell model based on the predicted results.ResultsA total of 53 major compounds were identified in the GBKC decoction. After network pharmacology-based virtual screening, 141 major targets and 39 main compounds were identified to be effective in the treatment of CB. The major targets were highly enriched in the tumor necrosis factor (TNF) signaling pathway, suggesting that GBKC could attenuate the inflammatory response in patients with CB. Furthermore, molecular docking results indicated that 20 pairs of components and target proteins relevant to the TNF pathway exhibited notable interactions. Among them, eight compound-target pairs exhibited good affinity as per SPR analysis. In addition, the production of interleukin 6 and TNF-α in LPS-induced MH-S cells was suppressed after GBKC treatment.ConclusionThis study successfully clarified the mechanism of action of GBKC against CB, which demonstrated that the integrated strategy described above is reliable for identifying the active compounds and mechanisms responsible for the pharmacological activities of GBKC decoction.

An Integrative Pharmacology-Based Approach for Evaluating the Potential Effects of Purslane Seed in Diabetes Mellitus Treatment Using UHPLC-LTQ-Orbitrap and TCMIP V2.0.

Portulaca oleracea L., known as the “vegetable for long life,” is an annual succulent herb that is widely distributed worldwide. Many clinical and experimental studies have demonstrated that purslane seed (MCXZ) can be used as an adjunctive and alternative therapy for the treatment of diabetes mellitus (DM). However, the underlying active constituents and pharmacological mechanisms through which MCXZ exerts effects in DM remain unclear. In the present study, we confirmed that MCXZ treatment resulted in hypoglycemic activity, lowering the fasting blood glucose and glycated hemoglobin levels in streptozotocin-induced diabetic mice. Then, ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry was used to systematically analyze the chemical profile of MCXZ, resulting in the identification of 84 constituents, including 31 organic acids and nine flavonoids. Finally, the Integrative Pharmacology-based Research Platform of Traditional Chinese Medicine was employed to analyze the key active components of MCXZ and the molecular mechanisms through which these components acted in DM. Ten key active compounds were identified based on the topological importance of their corresponding putative targets within the known DM-associated therapeutic target network of known MCXZ putative targets. Functionally, these candidate targets play critical anti-hyperlipidemia, anti-hyperglycemia, immunity regulation, and inflammatory roles involving DM-related pathways, such as the vascular endothelial growth factor (VEGF) signaling pathway and Fc gamma R-mediated phagocytosis, which indicated that MCXZ exhibited anti-diabetic activity through multi-faced actions.

Exploring the Active Components of Simotang Oral Liquid and Their Potential Mechanism of Action on Gastrointestinal Disorders by Integrating Ultrahigh-Pressure Liquid Chromatography Coupled with Linear Ion Trap-Orbitrap Analysis and Network Pharmacology.

Simotang oral liquid (SMT), a well-known traditional Chinese medicine formula composed of four medicinal and edible plants, has been extensively used for treating gastrointestinal disorders (GIDs) since ancient times. However, the major active constituents and the underlying molecular mechanism of SMT on GIDs are still partially understood. Herein, the preliminary chemical profile of SMT was first identified by ultrahigh-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap). In total, 70 components were identified. Then, a network pharmacology approach integrating target prediction, pathway enrichment analysis, and network construction was adopted to explore the therapeutic mechanism of SMT. As a result, 170 main targets were screened out and considered as effective players in ameliorating GIDs. More importantly, the major hubs were found to be highly enriched in a calcium signaling pathway. Furthermore, 26 core SMT-related genes were identified, which may play key roles in ameliorating gastrointestinal motility. In conclusion, this work would provide valuable information for further development and clinical application of SMT.

Characterization of the metabolites of H3B-6545 in vitro and in vivo by using ultra-high performance liquid chromatography combined with electrospray ionization linear ion trap-orbitrap tandem mass spectrometry.

H3B-6545 is a selective ERα covalent antagonist, which has been demonstrated to be effective in anti-tumor. To fully understand its mechanism of action, it is necessary to investigate the in vitro and in vivo metabolic profiles. For in vitro metabolism, H3B-6545 (50 μM) was incubated with the hepatocytes of rat and human for 2 h. For in vivo metabolism H3B-6545 was orally administered to rats at a single dose of 10 mg/kg, and plasma, urine and fecal samples were then collected. All samples were analyzed by using ultra-high performance liquid chromatography combined with linear ion trap-orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS) operated in positive ion mode. The structures of the metabolites were elucidated by comparing their MS and MS2 spectra with those of parent drug. A total of 11 metabolites, including a GSH adduct, were detected and structurally identified. M2, M7 and M8 were further unambiguously identified by using reference standards. Among these metabolites, M1, M5, M7 and M10 were newly found and reported for the first time. The metabolic pathways of H3B-6545 included deamination (M8 and M9), dealkylation (M2, M3 and M10), N-hydroxylation (M6), hydroxylation (M1 and M4), formation of amide derivatives (M5 and M7) and GSH conjugation (G1).

Chemical composition and bio-functional perspectives of Erica arborea L. extracts obtained by different extraction techniques: Innovative insights

Erica arborea L., also known as Estrella Gold, is traditionally used for several purposes. In this research, five different extraction techniques: accelerated solvent extraction (ASE), microwave-assisted extraction (MAE), maceration (MAC), soxhlet (SOE) and ultrasound-assisted extraction (UAE) were used to compare the total phenolic, flavonoids, total antioxidant activity and enzymatic activities of E. arborea extracts obtained different extraction techniques. The total phenolic and flavonoid contents were in the order of ASE > MAE > SOE > MAC > UAE. All extracts showed antioxidant, anticholinesterase, anti-tyrosinase and anti-diabetic activities. A highly sensitive method using ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC–LTQ–Orbitrap–MS) has been used for the qualitative analysis of obtained extracts. Seventy-two polyphenolic compounds were identified in all extracts. However, 20 components were quantified among the extracts. ASE was found to be a better extraction technique as compared to the other extraction techniques. E. arborea can be exploited in the discovery of bioactive natural products for the treatment of Alzheimer’s disease, diabetes and pigmentation problems.

Pharmacokinetics, bioavailability and metabolism of scopoletin in dog by ultra-high-performance liquid chromatography combined with linear ion trap-Orbitrap tandem mass spectrometry.

A highly sensitive and selective method based on ultra-high-performance liquid chromatography combined with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS) has been developed and validated for the determination of scopoletin in dog plasma. The analyte was extracted from plasma samples using acetonitrile and separated on an Acquity UPLC BEH C18 column (50 × 2.1 mm, 1.7 μm) with 0.05% ammonium hydroxide and acetonitrile as mobile phase. The developed method was linear over the concentration range of 1-500 ng/mL, with a correlation coefficient >0.9988. The intra- and inter-day precisions (RSD) were <8.93% while the accuracy (RE) ranged from -6.50 to 8.12%. Extraction recovery, matrix effect and stability for dog plasma samples were within the required limits. The validated method has been successfully applied to investigate the pharmacokinetics and metabolism of scopoletin in dog plasma after intravenous (1 mg/kg) and oral (10, 25, 50 mg/kg) administration. The results revealed that (a) scopoletin showed short elimination half-life in dog; (b) its oral bioavailability was low (within the range of 5.69-7.08%); (c) scopoletin showed dose-independent pharmacokinetic profiles in dog plasma over the dose range of 10-50 mg/kg; and (d) glucuronidation was the predominant metabolic pathway in dog.

Interactions of pharmacokinetic profiles of Ginkgotoxin and Ginkgolic acids in rat plasma after oral administration

Ginkgolic acids (GAs) and Ginkgotoxin (4′-O-methylpyridoxine, MPN) are main toxic compounds in Ginkgo biloba seeds which are widely used in the treatment of coughing in China. To evaluate the pharmacokinetics of GAs, MPN and their metabolites in rat plasma, a highly sensitive method followed by ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS) has been developed and validated. The proposed method is selective, precise and accurate enough of MPN and its metabolites (4-pyridoxic Acid, pyridoxal, and pyridoxine) for the pharmacokinetic study. After oral administration of MPN, the plasma concentrations of MPN and its metabolites were increased rapidly. Meanwhile, an investigation was carried out to compare the interactions of the pharmacokinetic profiles of MPN and GAs. Five GAs and main metabolites of GA (15:1) and GA (17:1) were also analyzed by using our previous method. After coadministration GAs with MPN, Tmax of MPN delayed and Cmax decreased. Meanwhile, Tmax of 4-pyridoxic Acid, pyridoxal, and pyridoxine were also showed a certain degree of delay. The concentrations of hydroxylation products of GA (15:1) and GA (17:1) increased at a slower rate and the area under the curves was significantly reduced. However, glucuronidation metabolites of GA (15:1) and GA (17:1) were increased faster than administered of GAs alone. The interactions of the pharmacokinetic profiles of GAs and MPN in rat plasma after oral administration were obviously observed.

Structure-based manual screening and automatic networking for systematically exploring sansanmycin analogues using high performance liquid chromatography tandem mass spectroscopy

Sansanmycins (SS), one of several known uridyl peptide antibiotics (UPAs) possessing a unique chemical scaffold, showed a good inhibitory effect on the highly refractory pathogens Pseudomonas aeruginosa and Mycobacterium tuberculosis, especially on the multi-drug resistant M. tuberculosis. This study employed high performance liquid chromatography-mass spectrometry detector (HPLC–MSD) ion trap and LTQ orbitrap tandem mass spectrometry (MS/MS) to explore sansanmycin analogues manually and automatically by re-analysis of the Streptomyces sp. SS fermentation broth. The structure-based manual screening method, based on analysis of the fragmentation pathway of known UPAs and on comparisons of the MS/MS spectra with that of sansanmycin A (SS-A), resulted in identifying twenty sansanmycin analogues, including twelve new structures (1-12). Furthermore, to deeply explore sansanmycin analogues, we utilized a GNPS based molecular networking workflow to re-analyze the HPLC–MS/MS data automatically. As a result, eight more new sansanmycins (13-20) were discovered. Compound 1 was discovered to lose two amino acids of residue 1 (AA1) and (2S, 3S)-N3-methyl-2,3-diamino butyric acid (DABA) from the N-terminus, and compounds 6, 11 and 12 were found to contain a 2′,3′-dehydrated 4′,5′-enamine-3′-deoxyuridyl moiety, which have not been reported before. Interestingly, three trace components with novel 5,6-dihydro-5′-aminouridyl group (16-18) were detected for the first time in the sansanmycin-producing strain. Their structures were primarily determined by detail analysis of the data from MS/MS. Compounds 8 and 10 were further confirmed by nuclear magnetic resonance (NMR) data, which proved the efficiency and accuracy of the method of HPLC–MS/MS for exploration of novel UPAs. Comparing to manual screening, the networking method can provide systematic visualization results. Manual screening and networking method may complement with each other to facilitate the mining of novel UPAs.

Identifying potential quality markers of Xin-Su-Ning capsules acting on arrhythmia by integrating UHPLC-LTQ-Orbitrap, ADME prediction and network target analysis

BackgroundQuality marker (Q-markers) has been proposed as a novel concept for quality evaluation and standard elaboration of traditional Chinese medicine (TCM). Xin-Su-Ning capsule (XSNC) has been extensively used for the treatment of arrhythmia with the satisfactory therapeutic effects in clinics. However, it is lack of reliable and effective Q-markers of this prescription. PurposeTo identify potential Q-markers of XSNC against arrhythmia. Study DesignAn integrative pharmacology-based investigation was performed. MethodsUltra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap) was performed to identify the preliminary chemical profile of XSNC in a rapid and high-throughput manner. Then, in silico Absorption-Distribution-Metabolism-Excretion (ADME) models were utilized to screen candidate active chemical compounds characterized by drug-likeness features. In addition, drug target-disease gene interaction network was constructed, and network features were calculated to identify key candidate targets and the potential Q-markers of XSNC against arrhythmia. ResultsA total of 41 chemical compounds with good drug-likeness and more chances to be absorbed into body were identified as the candidate bioactive chemical compounds which might offer contributions to the therapeutic effects of XSNC against arrhythmia in vivo. Following the prediction of 921 XSNC putative targets and the construction of XSNC putative target-known therapeutic target of arrhythmia interaction network, 315 hub nodes with high connectivity were selected. Functionally, the hub nodes were involved into modulation of cardiac sympatho-vagal balance, regulation of energy production and metabolism, as well as angiogenesis and vascular circulation during the development and progression of arrhythmia. Moreover, 63 major hubs with network topological importance were chosen as XSNC candidate targets against arrhythmia. Furthermore, berberine, palmatine, scopoletin, liquiritigenin, naringenin, formononetin, nobiletin, tangeretin, 5-demethylnobiletin, kushenol E and kurarinone hitting the corresponding XSNC candidate targets were screened out to be the potential Q-markers of XSNC against arrhythmia. ConclusionOur integrative pharmacology-based approach combining UHPLC-LTQ-Orbitrap, in silico ADME prediction and network target analysis may be efficient to identify potential Q-markers of TCM prescriptions. Our data showed that berberine, palmatine, scopoletin, liquiritigenin, naringenin, formononetin, nobiletin, tangeretin, 5-demethylnobiletin, kushenol E and kurarinone might function as candidate markers for qualitative evaluation of XSNC.

Development of a validated HPLC method for the quantitative determination of trelagliptin succinate and its related substances in pharmaceutical dosage forms

Trelagliptin succinate is a dipeptidyl peptidase IV (DPP-4) inhibitor which is used as a new long-acting drug for once-weekly treatment of type 2 diabetes mellitus (DM). In the present study, a rapid, sensitive and accurate high-performance liquid chromatography (HPLC) method was developed and validated for separation and determination of trelagliptin succinate and its eight potential process-related impurities. The chromatographic separation was achieved on a Waters Xselect CSH™ C18 (250mm×4.6mm, 5.0μm) column. The mobile phases comprised of 0.05% trifluoroacetic acid in water as well as acetonitrile containing 0.05% trifluoroacetic acid. The compounds of interest were monitored at 224nm and 275nm. The stability-indicating capability of this method was evaluated by performing stress test studies. Trelagliptin succinate was found to degrade significantly in acid, base, oxidative and thermal stress conditions and only stable in photolytic degradation condition. The degradation products were well resolved from the main peak and its impurities. In addition, the major degradation impurities formed under acid, base, oxidative and thermal stress conditions were characterized by ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap). The method was validated to fulfill International Conference on Harmonisation (ICH) requirements and this validation included specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision and robustness. The developed method in this study could be applied for routine quality control analysis of trelagliptin succinate tablets, since there is no official monograph.

Screening and Identification of the Metabolites in Rat Plasma and Urine after Oral Administration of Areca catechu L. Nut Extract by Ultra-High-Pressure Liquid Chromatography Coupled with Linear Ion Trap-Orbitrap Tandem Mass Spectrometry.

Areca catechu L. nut, a well-known toxic traditional herbal medicine, has been widely used to treat various diseases in China and many other Asian countries for centuries. However, to date the in vivo absorption and metabolism of its multiple bioactive or toxic components still remain unclear. In this study, liquid chromatography coupled with tandem mass spectrometry was used to analyze the major components and their metabolites in rat plasma and urine after oral administration of Areca catechu L. nut extract (ACNE). A total of 12 compounds, including 6 alkaloids, 3 tannins and 3 amino acids, were confirmed or tentatively identified from ACNE. In vivo, 40 constituents, including 8 prototypes and 32 metabolites were identified in rat plasma and urine samples. In summary, this study showed an insight into the metabolism of ACNE in vivo, which may provide helpful chemical information for better understanding of the toxicological and pharmacological profiles of ACNE.

Simultaneous quantification and semi-quantification of amentoflavone and its metabolites in human intestinal bacteria by liquid chromatography Orbitrap high-resolution mass spectrometry.

A quick, easy, effective method followed by ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap MS) was developed for the simultaneous identification and quantification of the metabolites produced by amentoflavone (AMF) in human intestinal bacteria from human feces. The method validated for quantification of AMF concerning precision, accuracy, recovery, matrix effect, stability and limits showed acceptable results. Compared with blank human intestinal bacteria chromatography, three metabolites were identified based on high-accuracy protonated precursors and multi-stage mass spectrometry (MSn ) using the proposed strategy. At the same time, a new method was developed for semi-quantification of three metabolites. We describe the trend over 24 h of concentration-time curves for AMF and its metabolites. Moreover, the main metabolic pathway of AMF was clarified in human intestinal bacteria. The method was validated and successfully applied to the detection and quantification of AMF and its metabolites.

Simultaneous quantification and semi-quantification of ginkgolic acids and their metabolites in rat plasma by UHPLC-LTQ-Orbitrap-MS and its application to pharmacokinetics study.

A highly sensitive method using ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS) has been developed and validated for the simultaneous identification and quantification of ginkgolic acids and semi-quantification of their metabolites in rat plasma. For the five selected ginkgolic acids, the method was found to be with good linearities (r>0.9991), good intra- and inter-day precisions (RSD<15%), and good accuracies (RE, from -10.33% to 4.92%) as well. Extraction recoveries, matrix effects and stabilities for rat plasm samples were within the required limits. The validated method was successfully applied to investigate the pharmacokinetics of the five ginkgolic acids in rat plasma after oral administration of 3 dosage groups (900mg/kg, 300mg/kg and 100mg/kg). Meanwhile, six metabolites of GA (15:1) and GA (17:1) were identified by comparison of MS data with reported values. The results of validation in terms of linear ranges, precisions and stabilities were established for semi-quantification of metabolites. The curves of relative changes of these metabolites during the metabolic process were constructed by plotting the peak area ratios of metabolites to salicylic acid (internal standard, IS), respectively. Double peaks were observed in all 3 dose groups. Different type of metabolites and different dosage of each metabolite both resulted in different Tmax.

Analysis of chemical constituents from Citrus aurantium by UHPLC-LTQ-Orbitrap-MS/MS

In this study, a ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS/MS) method was developed to analyze the chemical components in Citrus aurantium. C. aurantium were extracted with 75% methanol, and we applied a Thermo Scientific BDS Hypersil C₁₈ column (2.1 mm×150 mm, 2.4 μm) to UHPLC analysis with acetonitrile-water (containing 0.1% formic acid) in gradient as mobile phase. Elutes were then detected by ESI-LTQ-Orbitrap-MS/MS. A total of 27 components were identified, including fourteen flavonoids, seven coumarins, five limonoids and one alkaloid. This study showed an insight into the composition of C. aurantium, which could provide theoretical foundation for further study and utilization of the medicinal resources.