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1.
J Environ Sci (China) ; 97: 67-74, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32933741

RESUMO

Molecular level characterization of dissolved organic sulfur (DOS) by electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS) is necessary for further understanding of the role of DOS in the environment. Here, ESI spray solvent, a key parameter for ion production during ESI process, was investigated for its effect on the molecular characterization of DOS by ESI-FTICR MS. 100% MeOH as spray solvent was found for the first time to remarkably enhance the ionization efficiency of the majority of CHOS-molecules in NOM, which facilitated a total of 1473 CHOS-molecular formulas with one sulfur atom to be detected. The number of CHOS-molecular formulas obtained using 100%MeOH as spray solvent increased notably over 740 in comparison with those using 50% MeOH aqueous solution (731) or 50% ACN aqueous solution (653). Moreover, due to the enhancement of ionization efficiency of DOS during ESI processes, the tandem mass spectra of the NOM CHOS-molecules could be easily obtained using 100% MeOH as spray solvent, which were hardly obtained using 50% MeOH aqueous solution as spray solvent. The results of the tandem mass spectra suggested the first discovery of organosulfates or sulfonic acids in Suwannee River NOM sample. A simple method based on 100% MeOH as ESI spray solvent for advanced molecular characterization of DOS by ESI-FTICR MS was proposed and applied, and the results revealed more molecular information of DOS in sea DOM samples.


Assuntos
Ciclotrons , Espectrometria de Massas por Ionização por Electrospray , Análise de Fourier , Solventes , Enxofre
2.
J Chromatogr A ; 1626: 461353, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797833

RESUMO

This paper reports the development of an LC-ESI-MS2 method for the sensitive determination of hydroxylated polychlorinated biphenyls (OH-PCBs) in human serum samples. Congener-specific separation was achieved by using a polar-embedded stationary phase, previously optimized for the working group, which provided better separation of isobaric compounds than the common octadecylsilane phases. MS fragmentation patterns and energies showed differences among OH-PCB congeners, mainly depending on the position of OH-group and the number of chlorine atoms in the molecule, although the most intense transitions were always those corresponding to the neutral loss of an HCl group from the quasi-molecular ion cluster. The method allowed the determination of OH-PCBs with good linearity (dynamic linear range of four orders of magnitude with R2 higher than 0.995) and precision (relative standard deviations of absolute areas lower than 10%), and with better sensitivity than other similar methods previously described in the literature. Matrix effect has been evaluated and reduced to less than 10% by the addition of isotopically labeled standards and a 10-fold dilution of the final sample extract. The low iLODs provided by the developed method (from 1.2 to 5.4 fg µL-1 for all the OH-PCBs studied, except 4'-OHCB108, whose iLOD was 61 fg µL-1) allows dilution without losses of detected peaks. Finally, the applicability of the method has been demonstrated by analyzing human serum samples belonging to an interlaboratory exercise.


Assuntos
Cromatografia Líquida/métodos , Cromatografia de Fase Reversa/métodos , Bifenilos Policlorados/análise , Espectrometria de Massas em Tandem/métodos , Humanos , Hidroxilação , Bifenilos Policlorados/sangue , Bifenilos Policlorados/química , Espectrometria de Massas por Ionização por Electrospray
3.
Plant Mol Biol ; 104(3): 327-337, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32761540

RESUMO

KEY MESSAGE: Psoralen synthase and angelicin synthase responsible for the formation of psoralen and angelicin in Peucedanum praeruptorum Dunn were identified and functionally characterized, respectively. Furanocoumarins were reported to possess several activities such as anticancer, anti-inflammatory and neuroprotective, and function as phytotoxin and allelochemical in plants. Furanocoumarins are the main bioactive ingredient in P. praeruptorum which is a commonly used traditional Chinese medicine. Phenylalanine ammonia lyase (PAL), 4-coumarate: CoA ligase (4CL), p-coumaroyl CoA 2'-hyfroxylase (C2'H) were cloned previously to elucidate the biosynthetic mechanism of coumarin lactone ring. However, the genes involved in complex coumarins in P. praeruptorum have not been explored. Herein, putative psoralen synthase CYP71AJ49 and angelicin synthase CYP71AJ51 were cloned from P. praeruptorum. In vivo and in vitro yeast assays were conducted to confirm their activities. Furthermore, the results of High Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry (HPLC-ESI-MS) verified that CYP71AJ49 catalyzed the conversion of marmesin to psoralen, and CYP71AJ51 catalyzed columbianetin to angelicin. Subsequently, the expression profile showed that CYP71AJ49 and CYP71AJ51 were easily affected by environmental conditions, especially UV and temperature. The genes tissue-specific expression and compounds tissue-specific distribution pattern indicated the existence of substance transport in P. praeruptorum. Phylogenetic analysis was conducted with 27 CYP71AJs, CYP71AJ49 and CYP71AJ51 were classified in I-4 and I-2, respectively. These results provide further insight to understand the biosynthetic mechanism of complex coumarins.


Assuntos
Apiaceae/enzimologia , Apiaceae/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Furocumarinas/metabolismo , Proteínas de Plantas/metabolismo , Apiaceae/genética , China , Cromatografia Líquida de Alta Pressão/métodos , Coenzima A Ligases/genética , Cumarínicos/metabolismo , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/genética , Furocumarinas/química , Furocumarinas/genética , Regulação da Expressão Gênica de Plantas , Cinética , Medicina Tradicional Chinesa , Fenilalanina Amônia-Liase/genética , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/isolamento & purificação , Espectrometria de Massas por Ionização por Electrospray/métodos , Transcriptoma
4.
Nat Commun ; 11(1): 3818, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32732937

RESUMO

The formation of peptide bonds by energetic processing of amino acids is an important step towards the formation of biologically relevant molecules. As amino acids are present in space, scenarios have been developed to identify the roots of life on Earth, either by processes occurring in outer space or on Earth itself. We study the formation of peptide bonds in single collisions of low-energy He2+ ions (α-particles) with loosely bound clusters of ß-alanine molecules at impact energies typical for solar wind. Experimental fragmentation mass spectra produced by collisions are compared with results of molecular dynamics simulations and an exhaustive exploration of potential energy surfaces. We show that peptide bonds are efficiently formed by water molecule emission, leading to the formation of up to tetrapeptide. The present results show that a plausible route to polypeptides formation in space is the collision of energetic ions with small clusters of amino acids.


Assuntos
Aminoácidos/química , Simulação de Dinâmica Molecular , Peptídeos/química , Termodinâmica , beta-Alanina/química , Dipeptídeos/síntese química , Dipeptídeos/química , Íons/química , Oligopeptídeos/síntese química , Oligopeptídeos/química , Peptídeos/síntese química , Espectrometria de Massas por Ionização por Electrospray/métodos , Água/química
5.
Phytochemistry ; 177: 112452, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32773085

RESUMO

Polar lipids from the diatoms Diadesmis gallica and Navicula atomus were separated and their structures were determined using high resolution tandem MS HILIC-LC/ESI. This method allowed us to identify 34 classes of lipids, each containing dozens of molecular species, including regioisomers. The largest differences were found in two sulfur-containing lipids, sulfoquinovosyldiacylglycerol and phosphatidylsulfocholine caused probably by the remodeling of lipid species. These diatoms have been found to use several mechanisms to resolve growth in extreme environments, i.e. silica starvation. The presence of insoluble nano-SiO2 leads to the replacement of cellular phospholipids with sulfolipids. Regioisomer ratios also vary depending on the concentration of nano-SiO2 in the culture medium, i.e. the biosynthesis of polar lipids via the prokaryotic (plastidial) and/or eukaryotic (explastidial) pathways. Complex analyses of polar lipids using high resolution HILIC-LC/ESI-tandem, as used for diatoms, can also be used for other photosynthetic microorganisms.


Assuntos
Diatomáceas , Nanopartículas , Lipidômica , Dióxido de Silício , Espectrometria de Massas por Ionização por Electrospray
6.
Int J Nanomedicine ; 15: 5345-5360, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32801693

RESUMO

Background: Soft corals have been endorsed as a plentiful source of bioactive compounds with promising anti-inflammatory activities; therefore, exploring their potential as source of anti-inflammatory metabolites has stimulated a growing research interest. Purpose: To investigate the anti-inflammatory potential of the soft coral, Nephthea sp., in its bulk and silver nanostructure. Metabolomics analysis of Nephthea sp., followed by molecular docking studies, was also conducted in order to explore and predict the secondary metabolites that might provide its inhibitory actions on inflammation. Materials and Methods: The petroleum ether and ethyl acetate fractions were used to synthesize silver nanoparticles. The prepared silver nanoparticles were characterized through UV-vis spectrophotometric, transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR) analyses. Testing for the anti-inflammatory activity was performed against COX-1 and COX-2. Furthermore, liquid chromatography-mass spectrometry (LC-MS) based metabolomics analysis and molecular docking were also applied. Results: A variety of secondary metabolites were identified, among them, sesquiterpenes were found to prevail. The petroleum ether and acetone fractions of Nephthea sp. showed the highest COX-2 inhibitory activities, possibly attributable to their substantial contents of terpenoids. Additionally, the green synthesized silver nanoparticles of both the petroleum ether and ethyl acetate fractions of Nephthea sp. demonstrated higher anti-COX-2 properties. Conclusion: The obtained results showed the effectiveness of non-targeted metabolomics technique in metabolic profiling of Nephthea sp., helping the search for new bioactive metabolites in future chemical studies on this soft coral. The interesting anti-inflammatory potential of the tested extracts and their nanoparticles could also be relevant to the development of new, effective anti-inflammatory agents.


Assuntos
Antozoários/metabolismo , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Nanopartículas Metálicas/química , Prata/química , Alcanos/química , Animais , Antozoários/química , Anti-Inflamatórios/síntese química , Ciclo-Oxigenase 1/química , Ciclo-Oxigenase 1/metabolismo , Inibidores de Ciclo-Oxigenase 2/química , Inibidores de Ciclo-Oxigenase 2/farmacologia , Inibidores de Ciclo-Oxigenase/química , Inibidores de Ciclo-Oxigenase/farmacologia , Química Verde , Humanos , Metabolômica , Simulação de Acoplamento Molecular , Metabolismo Secundário , Sesquiterpenos/análise , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier
7.
PLoS One ; 15(8): e0234539, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32756554

RESUMO

Diabetes Mellitus (DM) accelerates coronary artery disease (CAD) and atherosclerosis, the causes of most heart attacks. The biomolecules involved in these inter-related disease processes are not well understood. This study analyzes biomolecules in the sera of patients with CAD, with and without type (T) 2DM, who are about to undergo coronary artery bypass graft (CABG) surgery. The goal is to develop methodology to help identify and monitor CAD patients with and without T2DM, in order to better understand these phenotypes and to glean relationships through analysis of serum biomolecules. Aorta, fat, muscle, and vein tissues from CAD T2DM patients display diabetic-related histologic changes (e.g., lipid accumulation, fibrosis, loss of cellularity) when compared to non-diabetic CAD patients. The patient discriminatory methodology utilized is serum biomolecule mass profiling. This mass spectrometry (MS) approach is able to distinguish the sera of a group of CAD patients from controls (p value 10-15), with the CAD group containing both T2DM and non-diabetic patients. This result indicates the T2DM phenotype does not interfere appreciably with the CAD determination versus control individuals. Sera from a group of T2DM CAD patients however are distinguishable from non-T2DM CAD patients (p value 10-8), indicating it may be possible to examine the T2DM phenotype within the CAD disease state with this MS methodology. The same serum samples used in the CAD T2DM versus non-T2DM binary group comparison were subjected to MS/MS peptide structure analysis to help identify potential biochemical and phenotypic changes associated with CAD and T2DM. Such peptide/protein identifications could lead to improved understanding of underlying mechanisms, additional biomarkers for discriminating and monitoring these disease conditions, and potential therapeutic targets. Bioinformatics/systems biology analysis of the peptide/protein changes associated with CAD and T2DM suggested cell pathways/systems affected include atherosclerosis, DM, fibrosis, lipogenesis, loss of cellularity (apoptosis), and inflammation.


Assuntos
Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/complicações , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Angiopatias Diabéticas/sangue , Adulto , Idoso , Biomarcadores/sangue , Proteínas Sanguíneas/metabolismo , Estudos de Casos e Controles , Ponte de Artéria Coronária , Doença da Artéria Coronariana/cirurgia , Estudos Transversais , Angiopatias Diabéticas/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Estudos Retrospectivos , Espectrometria de Massas por Ionização por Electrospray , Biologia de Sistemas , Espectrometria de Massas em Tandem
8.
PLoS One ; 15(8): e0237064, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32823271

RESUMO

A major source of epilepsy is Neurocysticercosis (NCC), caused by Taenia solium infection. Solitary cysticercus granuloma (SCG), a sub-group of NCC induced epilepsy, is the most common form of NCC in India. Current diagnostic criteria for SCG epilepsy require brain imaging which may not be available in communities where the disease is endemic. Identification of serum changes and potential biomolecules that could distinguish SCG epilepsy from idiopathic generalized epilepsy (IE), without the initial need for imaging, could assist in disease identification, understanding, and treatment. The objective here was to investigate, using mass spectrometry (MS), sera biomolecule differences between patients with SCG epilepsy or IE to help distinguish these disorders based on physiological differences, to understand underlying phenotypes and mechanisms, and to lay ground work for future therapeutic and biomarker analyses. Sera were obtained from patients with SCG or IE (N = 29 each group). Serum mass peak profiling was performed with electrospray ionization (ESI) MS, and mass peak area means in the two groups were compared using leave one [serum sample] out cross validation (LOOCV). Serum LOOCV analysis identified significant differences between SCG and IE patient groups (p = 10-20), which became non-significant (p = 0.074) when the samples were randomly allocated to the groups and reanalyzed. Tandem MS/MS peptide analysis of serum mass peaks from SCG or IE patients was performed to help identify potential peptide/protein biochemical and phenotypic changes involving these two forms of epilepsy. Bioinformatic analysis of these peptide/protein changes suggested neurological, inflammatory, seizure, blood brain barrier, cognition, ion channel, cell death, and behavior related biochemical systems were being altered in these disease states. This study provides groundwork for aiding in distinguishing SCG and IE patients in minimally invasive, lower-cost manners, for improving understanding of underlying epilepsy mechanisms, and for further identifying discriminatory biomarkers and potential therapeutic targets.


Assuntos
Epilepsia Generalizada/diagnóstico , Neurocisticercose/diagnóstico , Adulto , Animais , Biomarcadores/sangue , Cysticercus/patogenicidade , Diagnóstico Diferencial , Epilepsia/complicações , Epilepsia/diagnóstico , Epilepsia/tratamento farmacológico , Epilepsia Generalizada/tratamento farmacológico , Epilepsia Generalizada/metabolismo , Feminino , Granuloma/tratamento farmacológico , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Neurocisticercose/tratamento farmacológico , Neurocisticercose/metabolismo , Convulsões/tratamento farmacológico , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos
9.
J Breath Res ; 14(4): 046001, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32691749

RESUMO

Breath analysis by secondary electrospray ionization high-resolution mass spectrometry (SESI-HRMS) has potential for clinical diagnosis and drug monitoring. However, there is still a lack of benchmarking data that shows the capability of this technique and allows comparability with other breath analysis techniques. In this regard, the goal of this study was the identification of volatile compounds upon ingestion of a specific peppermint oil capsule to get benchmark data for real-time breath analysis with SESI-HRMS. This was done in the framework of a consortium set up by the International Association of Breath Research (IABR), aimed at comparing several analytical instruments for breath analysis. Breath temporal profiles of two subjects were analyzed with SESI-HRMS before and after ingestion of a peppermint oil capsule. The measurements were performed at two different locations using identical SESI-HRMS platforms to allow for comparability and benchmarking. Remarkably, along with the four major compounds (monoterpenes/cineole, menthone, menthofuran and menthol) reported by other members of the consortium, we detected 57 additional features significantly associated (ρ > 0.8) with the peppermint oil capsule, suggesting that this relatively simple intervention might trigger a more complex metabolic cascade than initially expected. This observation was made on both sites. Additional replicate experiments for one of the subjects suggested that a core of 35-40 unique molecules are consistently detected in exhaled breath upon ingestion of the capsule. In addition, we illustrate the analytical capabilities of real-time SESI-HRMS/MS to assist in the identification of unknown compounds. The results outlined herein showcase the performance of SESI-HRMS and enable comparison with other breath analysis techniques. Along with that, they strengthen the potential of this analytical technique for non-invasive drug monitoring and clinical diagnostic purposes.


Assuntos
Testes Respiratórios/métodos , Sistemas Computacionais , Expiração , Óleos Vegetais/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Adulto , Eucaliptol/análise , Feminino , Humanos , Isótopos , Mentol/análise , Metabolômica , Monoterpenos/análise
10.
Proc Natl Acad Sci U S A ; 117(28): 16167-16173, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601197

RESUMO

Saliva is a noninvasive biofluid that can contain metabolite signatures of oral squamous cell carcinoma (OSCC). Conductive polymer spray ionization mass spectrometry (CPSI-MS) is employed to record a wide range of metabolite species within a few seconds, making this technique appealing as a point-of-care method for the early detection of OSCC. Saliva samples from 373 volunteers, 124 who are healthy, 124 who have premalignant lesions, and 125 who are OSCC patients, were collected for discovering and validating dysregulated metabolites and determining altered metabolic pathways. Metabolite markers were reconfirmed at the primary tissue level by desorption electrospray ionization MS imaging (DESI-MSI), demonstrating the reliability of diagnoses based on saliva metabolomics. With the aid of machine learning (ML), OSCC and premalignant lesions can be distinguished from the normal physical condition in real time with an accuracy of 86.7%, on a person by person basis. These results suggest that the combination of CPSI-MS and ML is a feasible tool for accurate, automated diagnosis of OSCC in clinical practice.


Assuntos
Carcinoma de Células Escamosas/diagnóstico , Metabolômica , Neoplasias Bucais/diagnóstico , Saliva/metabolismo , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia , Estadiamento de Neoplasias , Testes Imediatos , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização por Electrospray
11.
J Chromatogr A ; 1625: 461278, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709330

RESUMO

A fast, non-invasive, high-performance liquid chromatographic screening method with electrospray ionization mass spectrometric detection was developed for the analysis of three major glycine-conjugated bile acids in human saliva. Using a mobile phase composed of 80% methanol and 0.1% formic acid, glycocholic, glycodeoxycholic, and glycochenodeoxycholic acids were separated in less than 4 minutes with sensitivity in the low nM range. Bile acids are thought to contribute to the pathology of various complications in gastroesophageal reflux disease, for instance, Barrett's esophagus, which may eventually lead to esophageal carcinoma. In this pilot study, samples of saliva obtained from 15 patients with Barrett's esophagus of various severities were compared to saliva samples from 10 healthy volunteers. Glycochenodeoxycholic acid was significantly elevated in the patients and principal component analysis of all bile acids could distinguish the most severe Barrett's esophagus patients. We also reported on the detection of glycochenodeoxycholic acid in exhaled breath condensate for the first time. The promising results of this pilot study warrant future investigation, aiming at non-invasive diagnostics of Barrett's esophagus susceptibility in patients with gastroesophageal reflux disease.


Assuntos
Esôfago de Barrett/metabolismo , Ácidos e Sais Biliares/análise , Cromatografia Líquida de Alta Pressão/métodos , Saliva/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Adulto , Esôfago de Barrett/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Análise de Componente Principal , Padrões de Referência , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador
12.
PLoS One ; 15(7): e0233814, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32726313

RESUMO

The clinical efficacy for treating of celastrol rheumatoid arthritis (RA) has been well-documented, but its mechanism of action remains unclear. Here we explored through what proteins and processes celastrol may act in activated fibroblast-like synoviocytes (FLS) from RA patients. Differential expression of genes and proteins after celastrol treatment of FLS was examined using RNA sequencing, label-free relatively quantitative proteomics and molecular docking. In this paper, expression of 26,565 genes and 3,372 proteins was analyzed. Celastrol was associated with significant changes in genes that respond to oxidative stress and oxygen levels, as well as genes that stabilize or synthesize components of the extracellular matrix. These results identify several potential mechanisms through which celastrol may inhibit inflammation in RA.


Assuntos
Anti-Inflamatórios/farmacologia , Artrite Reumatoide/tratamento farmacológico , Regulação da Expressão Gênica/efeitos dos fármacos , Proteômica/métodos , Transcriptoma/efeitos dos fármacos , Triterpenos/farmacologia , Anti-Inflamatórios/uso terapêutico , Artrite Reumatoide/genética , Artrite Reumatoide/patologia , Células Cultivadas , Cromatografia Líquida , Ontologia Genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Modelos Moleculares , Simulação de Acoplamento Molecular , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Espectrometria de Massas por Ionização por Electrospray , Sinoviócitos/efeitos dos fármacos , Sinoviócitos/metabolismo , Espectrometria de Massas em Tandem , Triterpenos/uso terapêutico
13.
Zhongguo Zhong Yao Za Zhi ; 45(11): 2634-2641, 2020 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-32627499

RESUMO

This study aims to establish a quantitative method of 4 aristolochic acids-DNA adducts in mice kidney and liver based on high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) for monitoring the content changes of aristolochic acids-DNA adducts. A Shiseido Capcellpak AQ C_(18) column(3 mm×100 mm, 3 µm) was used, with a mixture of 0.2% acetic acid-5 mmol·L~(-1) ammonium acetate as the aqueous phase and methanol as the organic phase for gradient elution. The multiple reaction monitoring(MRM) scanning method under positive mode by electrospray ionization(ESI) was performed for the detection of the aristolochic acids-DNA adducts which formed by combining aristolochic acid Ⅰ/Ⅱ with deoxyadenosine, deoxyguanosine, and deoxycytidine, respectively. Balb/c mice were given Guanmutong extract by gavage, and the relative content of aristolochic acids-DNA adducts in liver and kidney samples were analyzed within 60 days. It was found that the concentration of 4 aristolochic acids-DNA adducts in the kidney was significantly higher than that in the liver, and there were about 15.87 adducts in per 1×10~6 normal deoxynucleosides, which was 4.5-7.5 times than that of the liver. What's more, some adducts can still be detected on the 30 th day after administration. The concentration of the adducts in the liver was highest on the first day after administration, and a second peak appeared during the 7 th to 14 th days. The results indicated that aristolochic acids-DNA adducts are difficult to eliminate in vivo, and it is of great significance to study the mechanism of liver and kidney injury of aristolochic acid.


Assuntos
Ácidos Aristolóquicos , Animais , Cromatografia Líquida de Alta Pressão , Adutos de DNA , Fígado , Camundongos , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
14.
J Chromatogr A ; 1625: 461338, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709362

RESUMO

Until today, ion-pair reversed-phase chromatography is still the dominating method for analytical characterization of synthetic oligonucleotides. Its hyphenation with mass spectrometry, however, has some drawbacks such as ion-suppression in electrospray ionization. To overcome this problem, we present in this work a multiple heart-cutting (MHC) two-dimensional liquid chromatography (2D-LC) method with ultra-violet (UV) and electrospray ionization (ESI) mass spectrometry (MS) detection. A reversed-phase/weak anion-exchange (RP/WAX) stationary phase in the first dimension (1D) provides the selectivity for separation of structurally closely related oligonucleotide sequences and deletions (shortmers), respectively, using a mixed pH/triethylammonium phosphate buffer gradient at constant organic modifier content. Heart cuts of the oligonucleotide peaks are transferred to the second dimension (2D) via a multiple heart-cutting valve which is equipped with two loop decks. The 2D RP column is used for desalting via a diverter valve. Active solvent modulation enables to refocus the oligonucleotide peak into a sharp zone by 2D RP entirely free of non-volatile buffer components and ion-pair agents. Oligonucleotides can thus be sensitively detected by ESI-QTOF-MS under MS-compatible conditions.


Assuntos
Cromatografia de Fase Reversa/métodos , Oligonucleotídeos/química , Oligonucleotídeos/isolamento & purificação , Espectrometria de Massas por Ionização por Electrospray/métodos , Ânions , Cromatografia por Troca Iônica , Oligonucleotídeos/análise , Polímeros/química
15.
Chemosphere ; 260: 127458, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32693253

RESUMO

Advances in the ultra-high-resolution mass spectroscopy lead to a deep insight into the molecular characterization of natural organic matter (NOM). Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) has been used as one of the most powerful tools to decipher NOM molecules. In FTICR-MS analysis, the matrix effects caused by the co-occurring inorganic substances in water samples greatly affect the ionization of NOM molecules. The inherent complexity of NOM may hinder its component classification and formula assignment. In this study, basic principles and recent advances for sample separation and purification approaches, ionization methods, and the evolutions in formula assignment and data exploitation of the FTICR-MS analysis were reviewed. The complementary characterization methods for FTICR-MS were also reviewed. By coupling with other developed/developing characterization methods, the statistical confidence for inferring the NOM compositions by FTICR-MS was greatly improved. Despite that the refined separation procedures and advanced data processing methods for NOM molecules have been exploited, the big challenge for interpreting NOM molecules is to give the basic structures of them. Online share of the FTICR-MS data, further optimizing the FTICR-MS technique, and coupling this technique with more characterization methods would be beneficial to improving the understanding of the composition and property of NOM.


Assuntos
Ciclotrons , Análise de Fourier , Espectrometria de Massas por Ionização por Electrospray/métodos
16.
Environ Sci Pollut Res Int ; 27(32): 40296-40308, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32661964

RESUMO

In the present study, we characterized the phytochemical properties, which were specifically associated with phenolic compounds and antioxidant activities in six distinct ecotypes of Umbilicaria aprina Nyl. from Iran (including Kivarestan, Mishan, Takht-e Nader, Tochal, Sabalan, and Sahand) to detect diversities within the species. Total phenolic concentration (TPC) and radical scavenging capacities of U. aprina ecotypes were evaluated. Moreover, qualitative differences between chemical profiles were surveyed using liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Relatively moderate TPCs (Kivarestan = 36.12 ± 2.1, Mishan = 41.59 ± 2.2, Takht-e Nader = 31.85 ± 1.3, Tochal = 37.55 ± 2.3, Sabalan = 28.91 ± 2.5, and Sahand = 31.59 ± 2.2) were observed for ecotypes, but a very strong correlation (r = -0/842) was obtained between TPCs and IC50 values. Based on the results of LC-ESI-MS/MS, the following chemical substances were identified: orsellinic acid (1), lecanoric acid (2), evernic acid (3), gyrophoric acid (4), umbilicaric acid (5), hiascic acid (6), stictic acid (7) methyl hiascic acid (8), and an unknown substance (9). The MS/MS fragmentation scheme for each substance was determined and proposed. Wide discrepancies were observed in the chemical profiles of lichen ecotypes, which may corroborate the influence of ecological locality conditions, for example, altitude and slope aspects on secondary metabolism of lichen species U. aprina. The north-facing and east-facing ecotypes (Sabalan and Mishan, respectively) lacked depsidones (stictic acid) mainly because they receive the least direct radiation. Mishan ecotype, as the only east-facing ecotype, showed the most different chemical profile.


Assuntos
Antioxidantes , Líquens , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Ecótipo , Irã (Geográfico) , Espectrometria de Massas por Ionização por Electrospray , Inquéritos e Questionários , Espectrometria de Massas em Tandem
17.
Chemosphere ; 260: 127579, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32679375

RESUMO

As important emerging contaminants, nonsteroidal anti-inflammatory drugs (NSAIDs) are the most intensively prescribed pharmaceuticals introduced to drinking water due to their incomplete removal in wastewater treatment. While concentrations of NSAIDs in drinking water are generally low, they have been attracting increasing concern as a result of their disinfection byproducts (DBPs) generated in drinking water disinfection. In this work, detection methods were set up for four representative indole-derivative NSAIDs (indomethacin, acemetacin, sulindac, and etodolac) using ultra performance liquid chromatography/electrospray ionization-triple quadruple mass spectrometry (UPLC/ESI-tqMS). ESI+ was better for detection of indomethacin and sulindac, whereas ESI- was suitable to detection of acemetacin and etodolac. With optimized MS parameters, the instrument detection and quantitation limits of the four indole derivatives were achieved to be 1.1-24.6 ng/L and 3.7-41.0 ng/L, respectively. During chlorination, indomethacin and acemetacin could undergo five major reaction types (chlorine substitution, hydrolysis, decarboxylation, C-C coupling, and C-N cleavage) to form a series of DBPs, among which 19 were proposed/identified with structures. Based on the revealed structures of DBPs, transformation pathways of indomethacin and acemetacin in chlorination were partially elucidated. Notably, individual and mixture toxicity of indomethacin and acemetacin before/after chlorination were evaluated using a well-established acute toxicity assessment and a Hep G2 cell cytotoxicity assay, respectively. Results showed that the predicted acute toxicity of a few chlorination DBPs were higher than their precursors; chlorination substantially enhanced the mixture cytotoxicity of indomethacin by over 10 times and slightly increased the mixture cytotoxicity of acemetacin.


Assuntos
Anti-Inflamatórios não Esteroides/análise , Anti-Inflamatórios não Esteroides/toxicidade , Desinfecção/métodos , Poluentes Químicos da Água/análise , Anti-Inflamatórios não Esteroides/química , Cloro/química , Cromatografia Líquida , Desinfetantes/química , Água Potável/química , Halogenação , Células Hep G2 , Humanos , Indóis/análise , Indóis/química , Indóis/toxicidade , Indometacina/análogos & derivados , Indometacina/análise , Indometacina/química , Indometacina/toxicidade , Espectrometria de Massas por Ionização por Electrospray/métodos , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade , Purificação da Água/métodos
18.
Food Chem ; 333: 127506, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32679417

RESUMO

Artichoke floral stems (AFS) food waste by-products were examined for their phytochemical constituents and their in vitro and in vivo biological activities. Although that the highest total phenol content and total flavonoid content were found in ethyl acetate extract, methanol extract possessed the strongest DPPH and ABTS radical scavenging activity, and showed the highest reducing ferric antioxidant power (FRAP). The anti-acetylcholinesterase activity was higher in butanol extract, whereas the ethyl acetate extract had the highest inhibitory effect on heat-induced protein denaturation. In alloxan-induced diabetic mice, the AFS methanol extract (AFSE) rich in caffeoylquinic acids and flavones reduced blood glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, creatinine, and improved liver, and renal antioxidative status. Administration of AFSE to diabetic mice reduced total cholesterol, triglycerides, LDL-cholesterol, and the atherogenic index of plasma (AIP) suggesting its hypolipidemic action. Overall, AFS could be considered as attractive source of health-promoting ingredients.


Assuntos
Cynara scolymus/química , Compostos Fitoquímicos/análise , Extratos Vegetais/química , Alanina Transaminase , Animais , Antioxidantes/química , Antioxidantes/metabolismo , Bactérias/efeitos dos fármacos , Glicemia/análise , Candida albicans/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Cynara scolymus/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/patologia , Flavonoides/análise , Flores/química , Flores/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Fenóis/análise , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Extratos Vegetais/farmacologia , Caules de Planta/química , Caules de Planta/metabolismo , Espectrometria de Massas por Ionização por Electrospray
19.
Food Chem ; 333: 127516, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32683261

RESUMO

Benzotriazoles (BTRs) and benzothiazoles (BTs) are two groups of emerging concern and high production volume contaminants. Via the biomagnification of the food web, they could jeopardize human health. In this work, rapid determining the presence of five BTRs and two BTs in marketed fish was performed by a novel double-vortex-ultrasonic assisted matrix solid-phase dispersion (DVUA-MSPD) and UHPLC-electrospray ionization (+)-quadrupole time-of-flight mass spectrometry detection. Unlike traditional MSPD, we simplified the method without the use of mortar/pestle and SPE-column procedures. The DVUA-MSPD factors were screened by a multilevel categorical design, and then optimized by Box-Behnken Design plus with response surface methodology. The limits of quantification were 0.15-2 ng g-1 (dry weight). The satisfactory average recovery ranged from 70% to 93% with RSDs less than 9%. The developed method was successfully applied for the rapid determination of selected BTRs and BTs in fish samples at trace-level.


Assuntos
Benzotiazóis/química , Peixes/metabolismo , Extração em Fase Sólida/métodos , Animais , Benzotiazóis/análise , Benzotiazóis/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Limite de Detecção , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização por Electrospray , Ultrassom
20.
J Oleo Sci ; 69(6): 597-604, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32493885

RESUMO

The aim of the present research is to investigate the effect of three harvest date on the composition of apricot seed. Indeed, triacylglycerols (TAGs) content and composition were studied in developing Tunisian apricot varieties bitter (Bargoug), semi-sweet (Oud Rhayem) and sweet (Chechi Bazza) cultivars at intervals of early (14 DAP), mid phase (28 DAP) and full phase (55 DAP) of oil accumulation by UHPLC-ESI-MS method. Eleven molecular species of triacylglycerols were detected and identified as LLL, LLO, LLP, LOO, LLS/LOP, LPP, OOO, LOS, OOP, POP and OOS. At 14 DAP, LLO was the major TAGs molecular species with 35.4-52.6% (maximum reached in semi-sweet apricot). Others major TAGs were founded at lower content as LOO (17.5-40.3%) and OOO (5.7-12.7%). However, among maturity, three distinct profiles of TAGs molecular species were observed: bitter apricot was significantly richer in OOO molecular species than cultivars ones. However, semi-sweet and sweet cultivars were richer in LLO and LOO molecular species at different time-dates. These latter may provide a schedule for harvesting Tunisian apricot seeds with high quality of oil content.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Prunus armeniaca/química , Prunus armeniaca/crescimento & desenvolvimento , Sementes/química , Sementes/crescimento & desenvolvimento , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Triglicerídeos/química , Triglicerídeos/isolamento & purificação
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