Performance Liquid Chromatography Tandem Quadrupole Research Articles

A multi-technique based analytical platform for characterization and identification of a newly emerged steroid 6β-chlorotestosterone and its in-vivo epimeric metabolites

Doping athletes tend to use new and non-approved drugs in an attempt to circumvent the dope test. Recently, a package of unknown drug was obtained from black market claiming to contain steroid-like compound, which could not be readily identified due to the lack of commercially available reference standards. In order to characterize and identify the chemical structure of the unknown compound, ultra performance liquid chromatography high resolution mass spectrometry (UPLC-HRMS), high performance liquid chromatography tandem quadrupole mass spectrometry (HPLC-MS/MS), gas chromatography tandem quadrupole mass spectrometry (GC–MS/MS) and nuclear magnetic resonance (NMR) instruments were applied in this work. Based on the combined data, the unknown compound was identified as 6β-chlorotestosterone. The aim of this study was to find urinary metabolic biomarkers of 6β-chlorotestosterone for clinical research and doping control analysis. Ten in-vivo metabolites including four phase I metabolites and six phase II metabolites were characterized and potentially identified. The detailed structure of the phase I metabolite was successfully obtained by GC–MS/MS analysis of trimethylsilylation (TMS) released upon dissolution, overcoming the absence of useful fragment ions to demonstrate the structure of sulfate metabolites. Two strategies including metabolic mechanisms and retention time variation of steroids were introduced to determine and distinguish 3α/β- and 5α/β- epimeric metabolites. A comprehensive evaluation was conducted on time of appearance and detection of each metabolite. The sulfate metabolite 6β-chloro-5β-androstan-17-one-3β-O-sulfate (S1) could be detected up to 12 days after oral administration, which was considered to be the long term biomarker for 6β-chlorotestosterone abuse in clinical research and doping control analysis.

Targeted screening and quantification of flavonoids in the flavedo of navel oranges at different growth stages based on metabolomics technology

Plant-based food intake is essential for health promotion, especially in preventing chronic diseases. Flavonoids, as important bioactive substances found in citrus fruits, have a variety of health benefits, including antioxidant, anti-inflammatory, and cancer-inhibiting properties. This study used ultra-high performance liquid chromatography tandem quadrupole time of flight mass spectrometry to determine the flavonoids in the flavedo of navel oranges at different growth stages. Combined with chemometric methods to distinguish flavonoids at different growth stages, 15 differential flavonoids were deduced. In addition, the biomarker flavonoids in navel orange flavedo were quantified by high performance liquid chromatography mass spectrometry. The results showed that the contents of rutin, isosinensetin, and isorhamnetin all showed a trend of increasing and then decreasing during the growing period, while the contents of tangeretin and nobiletin would gradually decrease with the increase of fruit maturity. In addition, the analysis also revealed that the content of isorhamnetin was negatively correlated with the content of both narirutin and tangeretin, and it was hypothesized that isorhamnetin was in the same metabolic branching pathway as narirutin or tangeretin. The results of this study support the practical application of orange peel as a nutritional resource in functional foods.

XianLingGuBao protects against osteoporosis through activating STAT3 in vitro and vivo

BackgroundXianLingGuBao (XLGB) is a potent traditional Chinese patent medicine used to treat osteoporosis (OP), osteoarthritis, aseptic bone necrosis, and other musculoskeletal disorders. The current study aims to identify the active ingredients of XLGB and further elucidate its mechanism on OP treatment. MethodsExperimental pharmacology coupled with network pharmacology methods were used, and the effects of XLGB on mouse osteoblast MC3T3-E1 and ovariectomized (OVX) postmenopausal OP mouse model were detected. Furthermore, ultra performance liquid chromatography tandem quadrupole time of flight mass spectrometry (UPLC Q/TOF MS) was used to identify the active ingredients in XLGB for protecting osteoporosis. ResultsXLGB was shown to significantly promote the growth of MC3T3-E1 cells. It could promote the cell proliferation and enhance the formation of mineralized nodule of MC3T3-E1 cells. The efficacy of XLGB in preventing osteoporosis in OVX mice was also demonstrated. The network pharmacological analysis indicated that the top 5 active components of XLGB anti-OP were HX-14, 3-hydroxypsoralen, kaempferol, palmitic acid, and terpene ether. Both KEGG and GO analysis indicated that XLGB may inhibit bone loss through activating the STAT3. Results from the Western blot analysis confirmed that the expression and activity of STAT3 were affected by XLGB. ConclusionThis study clearly demonstrates that the activation of STAT3 plays an crucial role in the protective effect of XLGB against OP. These findings provide a solid experimental foundation on the extensive use of XLGB in the clinical treatment of OP.

Investigation of the material basis and mechanism of Lizhong decoction in ameliorating ulcerative colitis based on spectrum-effect relationship and network pharmacology

Ethnopharmacological relevanceLizhong decoction (LZD), a classical herbal prescription recorded by Zhang Zhongjing in Treatise on Febrile and Miscellaneous Diseases, has been extensively used to treat ulcerative colitis (UC) in clinical practice for thousands of years. However, its material basis and underlying mechanism are not yet clear. Aim of the studyThis study aims to explore the material basis and potential mechanism of LZD against UC based on the spectrum-effect relationship and network pharmacology. Materials and methodsFirst, LZD was extracted by a systematic solvent extraction method into four parts. Ultra-high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) technique was used to identify the compounds from different polar parts, and dextran sulfate sodium (DSS)-induced colitis model was used to evaluate the efficacy of each fraction. Then, the spectrum-effect analyses of compounds and efficacy indicators were established via grey relational analysis (GRA), bivariate correlation analysis (BCA) and partial least squares regression (PLSR). Finally, the potential mechanism of LZD for UC therapy was explored by network pharmacology, and the results were further verified by molecular docking and reverse transcription quantitative polymerase chain reaction (RT-qPCR). Results66 chemical components of LZD were identified by UPLC-Q-TOF-MS/MS technology. The pharmacodynamic results showed that extraction parts of LZD had different therapeutic effects on UC, among which ethyl acetate and n-butanol extracts had significant anti-colitis effects, which might be the main effective fractions of LZD. Furthermore, the spectrum-effect analyses indicated that 21 active ingredients such as liquiritin apioside, neolicuroside, formononetin, ginsenoside Rg1, 6-gingesulfonic acid, licoricesaponin A3, liquiritin, glycyrrhizic acid were the main material basis for LZD improving UC. Based on the above results, network pharmacology suggested that the amelioration of LZD on UC might be closely related to the PI3K-Akt signaling pathway. Additionally, molecular docking technology and RT-qPCR further verified that LZD could markedly inhibit the PI3K-Akt signaling pathway. ConclusionOverall, our study first identified the chemical compositions of LZD by using UPLC-Q-TOF-MS/MS. Furthermore, the material basis and potential mechanism of LZD in improving UC were comprehensively elucidated via spectrum-effect relationships, network pharmacology, molecular docking and experimental verification. The proposed strategy provided a systematic approach for exploring how herbal medicines worked. More importantly, it laid the solid foundation for further clinical application and rational development of LZD.

Comparative study on chemical components of Gannan navel orange in different maturity stages based on UPLC-QTOF-MS metabolomics

Metabolites changes during fruit growth are currently being studied intensively. In this experiment, Ultra-high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry was used to identify metabolites during the growing phase of navel oranges. A total of 63 metabolites were identified, and monitored changes in amino acid content. Principal component analysis and Partial least-squares-discriminate analysis were used to construct a cluster analysis model among navel orange metabolites. Among the 19 differential metabolites, flavonoids were the main metabolic markers during the growth of navel oranges. Correlation cluster analysis was used to fit the correlation between the characteristic components, and it was found that many flavonoids were highly correlated. Finally, combined with Kyoto Encyclopedia of Genes and Genomes enrichment analysis, the key metabolic pathway was identified as flavonoid synthesis. The α-glucosidase inhibition experiment showed that with the growth of navel orange, the inhibition rate of the metabolites to α-glucosidase activity decreased continuously. This study provides a necessary basis for exploring the metabolic mechanism of navel orange growth.

A comprehensive analytical strategy based on characteristic fragments to detect synthetic cannabinoid analogs in seized products and hair samples

Synthetic cannabinoids, one of the most widely abused new psychoactive substances (NPS), are now placed under national control generally in China. Due to continuous modification of synthetic cannabinoid structure, an ongoing dilemma in the forensic laboratory is that newly emerging substances cannot be detected by established methods. Thus, the screening methods for simultaneous detection of known or unknown substances have become research hotspots. In this study, the ultra high performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC-QqQ-MS) with precursor ion scan (PIS) as acquisition mode was used for prescreening purposes of all possible synthetic cannabinoids-related substances. In detail, four common characteristic fragments, m/z of 144.0, 145.0, 135.1, and 109.0 corresponding to acylium-indole, acylium-indazole, adamantyl, and fluorobenzyl cation respectively, were selected for PIS mode, and their collision energies were optimized by 97 available synthetic cannabinoids standards with relevant structures. Those suspicious signals observed in the screening experiment were confirmed by ultra high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) via high-resolution MS and MS2 data obtained by full scan (TOF MS) and product ion scan mode. After methodological validation, the integrated strategy established above was applied to the screening and identification of the seized e-liquids, herbal blends and hair samples, confirming the presence of multiple synthetic cannabinoids in these samples. In particular, a novel synthetic cannabinoid was identified as 4 F-ABUTINACA, for which no relevant high-resolution mass spectrometry (HRMS) data has been retrieved until now, making this study the first to report the cleavage pattern of this compound in electrospray ionization (ESI) mass spectrometry. In addition, four other suspected by-products of the synthetic cannabinoids were found in the herbal blends and e-liquids, and their possible structures were also deduced via the information from high-resolution mass spectra.

The Study of Yak Colostrum Nutritional Content Based on Foodomics.

The utilization of yak milk is still in a primary stage, and the nutrition composition of yak colostrum is not systematically characterized at present. In this study, the lipids, fatty acids, amino acids and their derivatives, metabolites in yak colostrum, and mature milk were detected by the non-targeted lipidomics based on (ultra high performance liquid chromatography tandem quadrupole mass spectrometer) UHPLC-MS, the targeted metabolome based on gas chromatography-mass spectrometer (GC-MS), the targeted metabolome analysis based on UHPLC-MS, and the non-targeted metabolome based on ultra high performance liquid chromatography tandem quadrupole time of flight mass spectrometer (UHPLC-TOF-MS), respectively. Meanwhile, the nutrition composition of yak colostrum was compared with the data of cow mature milk in the literatures. The results showed that the nutritive value of yak colostrum was higher by contrast with yak and cow mature milk from the perspective of the fatty acid composition and the content of Σpolyunsaturated fatty acids (PUFAs), Σn-3PUFAs; the content of essential amino acid (EAA) and the ratio of EAA/total amino acid (TAA) in yak colostrum were higher than the value in yak mature milk; and the content of functional active lipids including phosphatidylcholines (PC), phosphatidylglycerol (PG), phosphatidylserine (PS), lyso-phosphatidylcholine (LPC), lyso-phosphatidylglycerol (LPG), lyso-phosphatidylinositol (LPI), sphingomyelin (SM), ganglioside M3 (GM3), ganglioside T3 (GT3), and hexaglycosylceramide (Hex1Cer) in yak colostrum, was higher than the value of yak mature milk. Moreover, the differences of nutritive value between yak colostrum and mature milk were generated by the fat, amino acids and carbohydrate metabolism that were regulated by the ovarian hormone and referencesrenin-angiotensin-aldosterone system in yaks. These research results can provide a theoretical basis for the commercial product development of yak colostrum.

In vitro and in vivo exploration of the anti-atopic dermatitis mechanism of action of Tibetan medicine Qi-Sai-Er-Sang-Dang-Song decoction.

Tibetan medicine Qi-Sai-Er-Sang-Dang-Song Decoction(QSD, ཆུ་སེར་སེང་ལྡེང་སུམ་ཐང་།)is a traditional Tibetan medical formulation with demonstrated clinical benefits in atopic dermatitis (AD). However, its potential mechanism and molecular targets remain to be elucidated. This study aims to explore the activity and mechanism of QSD on AD in multiple dimensions by combining in vitro and in vivo experiments with network pharmacology. The AD effect of QSD was investigated by evaluating the levels of nitric oxide (NO) and interleukin-6 (IL-6) in the lipopolysaccharide (LPS) stimulated RAW264.7cells. AD-like skin lesions in female BALB/c mice were induced by 2,4-dinitrochlorobenzene (DNCB). QSD or dexamethasone (positive control) were gavagely administered daily for 15 consecutive days. The body weight and skin lesion severity were recorded throughout the study. Enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) analysis were used to illuminate the molecular targets associated with the anti-AD effects of QSD. Meanwhile, the ingredients of QSD in the blood were revealed and analyzed by Ultra performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) method. Network pharmacology was used to predict the targets and mechanism of active ingredient therapy for AD. In addition, the network pharmacology outcomes were further verified by molecular docking. After treatment with QSD, the levels of NO and IL-6 were decreased in the cell supernatant. Herein, QSD markedly decreased the eosinophil and mast cells infiltration in the dorsal skin of the 2,4-dinitrochlorobenzene. Moreover, QSD reconstructed the epidermal barrier by increasing the content of collagen fibers and changing the arrangement of DNCB-treated mice. QSD not only inhibited the levels of tumor necrosis factor-α (TNF-α) and interleukin-12 (IL-12) but also inhibited phosphorylation of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) proteins in the dorsal skin. Four active ingredients were identified through UPLC-Q-TOF/MS, including (-)-epicatechin, kaempferol-7-O-glucoside, cassiaside, and questin. After the network pharmacological analysis, six core targets of QSD closely related to AD were obtained, including TNF-α, IL-6, Caspase-3 (CASP3), Epidermal growth factor (EGFR), Peroxisome proliferator-activated receptor gamma (PPARG), and Neurotrophic Receptor Tyrosine Kinase 1 (NTRK1). Meanwhile, through Gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, the Mitogen-activated protein kinase (MAPK) signaling pathway occupies an important position in the QSD treatment of AD. The molecular docking results showed that the six core targets are stable in binding to the four active ingredients as indicated by the molecular docking results. The anti-AD effect of QSD might be related to the reconstruction of the epidermal barrier and inhibition of inflammation, which regulated the MAPK pathway. Hence, it provided a promising idea for the study of Tibetan medicine prescriptions for the treatment of AD.

A metabolic biomarker panel of restless legs syndrome in peritoneal dialysis patients.

Restless legs syndrome (RLS) is a neuromotor disorder, and dialysis patients are more likely to develop RLS. RLS often causes sleep disorders, anxiety and depression in patients. It will increase the risk of death and severely affect the life of patients. At present, RLS has not received enough recognition and attention, and the misdiagnosis rate can reach more than 10%. The discovery set selected 30 peritoneal dialysis (PD) patients and 27 peritoneal dialysis patients with RLS (PD-RLS). A metabolomics method based on ultra performance liquid chromatography tandem quadrupole time-of-flight mass spectrometric method (UPLC-Q-TOF/MS) was used to analyze the differential metabolites of the two groups. 51 PD patients and 51 PD-RLS patients were included in the validation set. The receiver operating characteristic (ROC) analysis was used to evaluate the early diagnostic biomarkers, and the correlation between the differential metabolites and laboratory test indexes was analyzed to explore the biological function of the differential metabolites. Through the integrated analysis, four metabolites can be used as markers for the diagnosis of PD-RLS, including Hippuric acid, Phenylacetylglutamine, N,N,N-Trimethyl-L-alanyl-L-proline betaine and Threonic acid. Through ROC analysis, it is found that they can be used as a metabolic biomarker panel, and the area under the curve of this combination is more than 0.9, indicating that the panel has good diagnostic and predictive ability. Metabolomics based on UPLC-Q-TOF/MS technology can effectively identify the potential biomarkers, and provide a theoretical basis for the early diagnosis, prevention and treatment on PD-RLS.

Inhibition of methylmercury uptake by freshwater phytoplankton in presence of algae-derived organic matter

As the first step of methylmercury (MeHg) entry into the aquatic food webs, MeHg uptake by phytoplankton is crucial in determining the final human MeHg exposure risks. MeHg availability to plankton is regulated by dissolved organic matter (DOM) in the water, while the extent of the impacts can vary largely based on the sources of DOM. Here, we investigated impacts of DOM sources on MeHg bioconcentration by three freshwater phytoplankton species (i.e. S. quadricauda, Chlorella sp., Microcystis elabens) in the laboratory system. We found that algae-derived DOM would prohibited the cellular MeHg bioconcentration by a percent up to 77–93%, while the soil-derived DOM didn't show similar inhibition effects. DOM characterization by the excitation‒emission matrices, Fourier transform infrared spectrum, ultra‒high performance liquid chromatography‒tandem quadrupole time of flight mass spectrometry shown that the molecular size of S-containing compound, rather than thiol concentration, has played a crucial role in regulating the MeHg uptake by phytoplankton. Climate change and increasing nutrient loadings from human activities may affect plankton growth in the freshwater, ultimately changing the DOM compositions. Impacts of these changes on cellular MeHg uptakes by phytoplankton should be emphasized when exploring the aquatic Hg cycling and evaluating their risks to human beings and wild life.

Preclinical Pharmacokinetics, Tissue Distribution and in vitro Metabolism of FHND6091, a Novel Oral Proteasome Inhibitor.

IntroductionFHND6091, a novel N-capped dipeptidyl boronic acid proteasome inhibitor with promising pharmacological properties, entirely converted into active form FHND6081 under physiological conditions. The proteasome, a key component of the ubiquitin-proteasome pathway (UPP), has emerged as a validated target of multiple myeloma (MM) therapeutics. FHND6091 is a selective oral proteasome inhibitor that binds irreversibly to the β5 submit of the 20S proteasome and exerts anti-cancer roles.MethodsIn this study, we investigated the metabolic stability, metabolite production, metabolic pathways and plasma protein binding (PPB) of FHND6081 along with its absorption, tissue distribution, excretion (ADME) and pharmacokinetics (PK) in animals.ResultsUltra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) identified a total of nine new metabolites after co-incubation with FHND6091 in hepatocytes from different species. A hypothetical CYP450-metabolic pathway including dehydrogenation, N-dealkylation plus mono-oxygenation and other was proposed. In addition, FHND6081 was highly bound to plasma proteins (>99%); nevertheless, it preferred to partition to red blood cells (B/P ratio: 4.91). The results of microsomal metabolic stability corroborated that FHND6081 was a moderate-clearance compound. In Caco-2 cell experiments, the compound displayed modest permeability suggesting that it may show limited bioavailability via oral routes. Furthermore, FHND6081 was extensively distributed in rats and the highest exposure was achieved in the stomach followed by the small intestine and adrenal gland. Pharmacokinetic studies were done by using Sprague-Dawley (SD) rats, oral absorption was fast and plasma exposure was dose-dependent and oral bioavailability were low. At the same dose, FHND6081 exposure was severalfold higher in whole blood than in plasma, which was consistent with blood cell partitioning. Moreover, only a small fraction of the parent compound was excreted via feces and urine and oxidative metabolites were detected in feces and plasma.ConclusionThe overall preclinical pharmacokinetic profile supported the selection and development of FHND6091 as a clinical candidate.

Simultaneous screening and analysis of 155 veterinary drugs in livestock foods using ultra-high performance liquid chromatography tandem quadrupole linear-ion-trap mass spectrometry

Veterinary drugs are widely used to improve the health and growth of livestock. The supervision of these residues is necessary to ensure food safety. A high-throughput method based on Oasis PRiME HLB with solid phase extraction for simultaneous qualitative and quantitative analysis of 155 veterinary drugs in livestock foods was developed by the ultra-high performance liquid chromatography tandem quadrupole linear-ion-trap mass spectrometry (UHPLC-QTRAP-MS). The limits of detection and quantification ranged from 0.5 μg/kg to 5 μg/kg and 2 μg/kg to 20 μg/kg, respectively. For over 85% of the analytes, the recoveries were between 60% and 120%. The positive simulated samples perfectly matched with a purity fit value over 70% from the self-built library. The screening results of UHPLC-QTRAP-MS were almost consistent with UHPLC tandem quadrupole-exactive orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap/MS). The evaluated UHPLC-QTRAP-MS method was powerful and reliable for the screening and quantification of veterinary drugs in real samples.

Efficient ofloxacin degradation via photo-Fenton process over eco-friendly MIL-88A(Fe): Performance, degradation pathways, intermediate library establishment and toxicity evaluation

The high-throughput production of the eco-friendly MIL-88A(Fe) was achieved under mild reaction conditions with normal pressure and temperature. The as-prepared MIL-88A(Fe) exhibited efficient photo-Fenton catalytic ofloxacin (OFL) degradation upon visible light irradiation with good stability and reusability. The OFL (20.0 mg/L) was completely degraded within 50 min under visible light with the aid of MIL-88A(Fe) (0.25 g/L) and H2O2 (1.0 mL/L) in aqueous solution (pH = 7.0). The hydroxyl radicals (·OH) are the main active species during the photo-Fenton oxidation process. Meanwhile, the degradation intermediates and the corresponding degradation pathways were identified and proposed with the aid of both ultra-high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) and density functional theory (DFT) calculations. Finally, the degradation product library was firstly established to identify intermediate transformation products (TPs) with their variation of concentration, and their corresponding toxicologic activities were assessed via Toxtree and T.E.S.T software as well. Finally, the MIL-88A is efficient and stable with four cycles’ catalysis operations, demonstrating good potential for water treatment.

Ultratrace analysis of per- and polyfluoroalkyl substances in drinking water using ice concentration linked with extractive stirrer and high performance liquid chromatography – tandem mass spectrometry

Detection of drinking water contaminants is vital to the protection of human health. One group of contaminants that have recently generated serious concerns over health risks are per- and polyfluoroalkyl substances (PFAS). These compounds are very bio-persistent, leading to their detection in all types of water sources, including drinking water. While analysis of drinking water for PFAS is important, it is currently arduous to detect ultratrace levels of these contaminants. Specifically, current ultratrace PFAS analysis methods are difficult, costly, require large sample volumes, and consume relatively large volumes of organic solvent. In the present work, an analytical method using Ice Concentration Linked with Extractive Stirrer (ICECLES) and high performance liquid chromatography—tandem quadrupole mass spectrometry (HPLC-MS/MS), was developed and validated to provide simple and ultratrace analysis of drinking water for 14 PFAS. The method featured a relatively low sample volume requirement (10 mL), automated extraction, minimal matrix effects, and minimal organic solvent use (i.e., the method requires only 50 µL of methanol per sample). The method produced a wide linear range of 0.5 to 500 ng/L, ultratrace limits of detection (0.05 to 0.3 ng/L), and good accuracy and precision (i.e., 87 to 108% accuracy and ≤19% relative standard deviation as a measure of precision). This method was tested on drinking water samples from across the United States and detected at least one PFAS compound in 52 of the 53 drinking water samples tested. Perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), and perfluoroheptanoic acid (PFHpA) were detected in 89, 96, and 77% of the samples tested with maximum concentrations of 268 ng/L for PFHxA, 213 ng/L for PFOA, and 75.7 ng/L for PFHpA. Additionally, perfluorononanoic acid, perfluorodecanoic acid, and perfluoroheptanoic acid were each detected in at least one drinking water sample at concentrations > 20 ng/L. The availability of the method presented here allows ultratrace detection of PFAS while circumventing many of the disadvantages of current methods.

Comprehensive investigation of pharmacodyamic material basis of Wikstroemia indica (L.) C. A. Mey. by serum pharmacochemistry and bivariate correlation analysis

In this study, the theory of serum pharmacochemistry of traditional Chinese medicine was used to analyze the constituents absorbed into serum after oral administration of Wikstroemia indica (L.) C. A. Mey. by ultra high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). The micro-liquid dilution method was used to determine the minimum inhibitory concentration of the serum containing Wikstroemia indica. The bivariate correlation analysis method was used to study the spectral-efficiency relationship between the drug-containing serum and the antibacterial activity, and find the main antibacterial active components in serum containing Wikstroemia indica. A total of 26 serum migration components were identified or speculated in the samples, including 11 prototype components and 15 metabolites. Of which, syringic acid, caffeic acid, dihydrocaffeic acid, 4-hydroxybenzoic acid, hippuric acid, 3-hydroxy-3-(4-hydroxy-3-methoxyphenyl)propanoic acid, triumbelletin, (7R)-3-hydroxy-1-methyl-2-oxo-7-(prop-1-en-2-yl)-2,3,5,6,7,8- hexahydroazulene-4-carbaldehyde and (1S,3aS,8aS)-1,3,5-trihydroxy-1,4-dimethyl-7-(propan-2- ylidene)octahydroazulen-6(1H)-one were bacteriostatic active substances. It is the first time to study the constituents in serum containing Wikstroemia indica and reveal its antibacterial pharmacodyamic material basis. The above works provide scientific reference for the in-depth study of Wikstroemia indica.

Study on the Analytical Method of Solid Phase Extraction-Ultra Performance Liquid Chromatography Tandem Quadrupole Linear Ion Trap Mass Spectrometry for 12 Perfluorinated Compounds in Human Urine

To establish a method for simultaneous determination of 12 kinds of perfluorinated compounds (PFCs) in human urine based on ultra performance liquid chromatography tandem quadrupole linear ion trap mass spectrometry (UPLC-QTtrap-MS). After pH adjustment with 2% formic acid, the urine samples were loaded on a WAX solid phase extraction (SPE) cartridge for extraction, purification and concentration. The eluates were collected, concentrated to dryness under nitrogen, and reconstituted with 10 mmol/L ammonium acetate aqueous solution-methanol ( V water∶ V methanol = 70∶30) before injection. UPLC was performed on a C 18 cartridge, and methanol and 10 mmol/L ammonium acetate aqueous solution was used as mobile phases with gradient elution. QTtrap-MS was operated in multiple reaction monitoring (MRM) mode, and the internal standard calibration curves were applied for quantitative analysis. Good linearity was obtained in the linear range, with the method detection limits and method quantification limits being 0.032 ng/L-6.5 ng/L and 0.10 ng/L-21 ng/L, respectively, for the 12 kinds of PFCs. The spiked recoveries of the 12 kinds of PFCs were 91.5%-114%, with the intra-day precision and the inter-day precision being 0.57%-16.0% and 1.88%-20.1%, respectively. The established method was applied to the determination of 12 kinds of PFCs in the urine samples of primary school students collected in one area. Nine kinds of PFCs were detected in the urine samples in this area. Among the PFCs detected, perfluorobutanesulfonic acid (PFBS) and perfluorooctanoic acid (PFOA) were the main PFCs found in the student urine samples. The method established in this study could be used to simultaneously examine 12 kinds of PFCs in urine. The method combined SPE with isotope internal standard correction and achieved good sensitivity and accuracy.

Qualitative and quantitative analysis of Paris polyphylla var. chinensis by UPLC-Q-TOF-MS/MS and HPLC

Paridis Rhizoma(PR) is prepared from the dried rhizome of Paris polyphylla var. yunnanensis(PPY) or P. polyphylla var. chinensis(PPC) in Liliaceae family. The rapid development of PPY or PPC planting industry resulted from resource shortage has caused the waste of a large number of non-medicinal resources. To clarify the chemical compositions in rhizomes, fibrous roots, stems, leaves, seeds and pericarps of PPC, and explore the comprehensive application value and development prospect of these parts, the qualitative and quantitative analyses on the different parts of PPC were carried out by ultra-high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS/MS) and high performance liquid chromatography(HPLC). A total of 136 compounds were identified, including 112 steroidal saponins, 6 flavonoids, 11 nitrogen-containing compounds and 7 phytosterols. Rhizomes, fibrous roots, and seeds mainly contained protopennogenyl glycosides and pennogenyl glycosides; leaves and stems mainly contained protodiosgenyl glycosides and diosgenyl glycosides; pericarps mainly contained pennogenyl glycosides, followed by diosgenyl glycosides. The total level of four saponins was the highest in fibrous roots and rhizomes, followed by those in the pericarps and arillate seeds, and the lowest in the stems and exarillate seeds. This study can provide data support for the comprehensive development and rational application of non-medicinal parts of PPC.

Serum metabolomics in latent pneumoconiosis tuberculosis patients based on ultra performance liquid chromatography tandem quadrupole time of flight mass spectrometry

Objective: To explore the non-target metabonomics of serum in worker's pneumoconiosis (CWP) patients with latent tuberculosis and the biomarkers of latent tuberculosis infection of pneumoconiosis. Methods: In December 2018, 39 CWP inpatients from a hospital in Beijing were taken as subjects. The subjects were screened for latent tuberculosis using the in vitro release test of mycobacterium tuberculosis-interferon (IGRAs) test. According to the screening results, 21 positive patients with latent tuberculosis infection were selected as the latent tuberculosis group of pneumoconiosis. While 18 negative patients with CWP alone were selected as the pneumoconiosis group. Polarity components of metabolites were analyzed by UPLC-QTOF/MS. The data was processed with Progenesis QI software for multidimensional statistical analysis. Identification of structure of differential metabolites were matched through accurate mass and secondary mass spectrum. Searching the Human Metabolome Database (HMDB) , differential metabolites were imported into MetaboAnalyst 4.0 to analyze the metabolic pathways. Results: All 42 differential metabolites were screened out. Excepted for exogenous metabolites, 14 endogenous differential metabolites were identified. Compared with the pneumoconiosis group, 6 metabolites including PC [18∶4 (6Z, 9Z, 12Z, 15Z) /P-18∶1 (11Z) ], 3-Oxododecanoyl-CoA in the latent tuberculosis group were up-regulated, while 8 metabolites including the Stearoyl-CoA, (2S) -Pristanoyl-CoA were down-regulated. These results might be related to lipid, fatty acid and arachidonic acid metabolism pathways. Conclusion: There are significant differences in serum metabonomics between the patients with latent tuberculosis of pneumoconiosis and the patients with ordinary pneumoconiosis, which provide a reference for the study of biomarkers for the diagnosis of latent tuberculosis infection of pneumoconiosis.

Metabolite identification, tissue distribution, excretion and preclinical pharmacokinetic studies of ET-26-HCl, a new analogue of etomidate.

ET-26-HCl, a novel anaesthetic agent with promising pharmacological properties, lacks extensive studies on pharmacokinetics and disposition in vitro and in vivo. In this study, we investigated the metabolic stability, metabolite production and plasma protein binding (PPB) of ET-26-HCl along with its tissue distribution, excretion and pharmacokinetics in animals after intravenous administration. Ultra-high performance liquid chromatography–tandem quadrupole time-of-flight mass spectrometry identified a total of eight new metabolites after ET-26-HCl biotransformation in liver microsomes from different species. A hypothetical cytochrome P450-metabolic pathway including dehydrogenation, hydroxylation and demethylation was proposed. The PPB rate was highest in mouse and lowest in human. After intravenous administration, ET-26-HCl distributed rapidly to all tissues in rats and beagle dogs, with the highest concentrations in fat and liver. High concentrations of ET-26-acid, a major hydroxylation metabolite of ET-26-HCl, were found in liver, plasma and kidney. Almost complete clearance of ET-26-HCl from plasma occurred within 4 h after administration. Only a small fraction of the parent compound and its acid form were excreted via the urine and faeces. Taken together, the results added to a better understanding of the metabolic and pharmacokinetic properties of ET-26-HCl, which may contribute to the further development of this drug.

Analysis of constituents from different parts of Callicarpa nudiflora by UPLC-Q-TOF-MS/MS

The aim of this study was to clarify the main components of the green leaves of Callicarpa nudiflora,and to compare the difference of main components between the green leaves,yellow leaves,branches and seeds. In this study,ultra-high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS/MS) coupled with the UNIFI scientific information system was adopted. And the identification of the main chemical components of C. nudiflora was combined with reference materials,literatures and online database. In addition,the difference of main components was analyzed by Progenesis QI,principal component analysis(PCA) and orthogonal partial least squares discriminant(OPLS-DA). A total of 57 compounds were identified in green leaves,including phenylpropanoids,flavonoids and iridoids. Among them,the relative content of phenylethanoid glycosides was highest. Furthermore,the PCA analysis showed that there are significant differences in main components of the branches and other parts of C. nudiflora. Combined with OPLS-DA analysis,nudifloside,parvifloroside B and β-hydroxysamioside were selected as the characteristic components for distinguish the leaves and branches of C. nudiflora. Our study provided a scientific basis for the collection and identification of C. nudiflora.