共查询到20条相似文献,搜索用时 15 毫秒
1.
《Journal of separation science》2017,40(16):3188-3195
Baidianling Capsule, which is made from 16 Chinese herbs, has been widely used for treating vitiligo clinically. In this study, the sensitive and rapid method has been developed for the analysis of chemical components in Baidianling Capsule by gas chromatography–mass spectrometry in combination with retention indices and high‐performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. Firstly, a total of 110 potential volatile compounds obtained from different extraction procedures including alkanes, alkenes, alkynes, ketones, ethers, aldehydes, alcohols, phenols, organic acids, esters, furans, pyrrole, acid amides, heterocycles, and oxides were detected from Baidianling Capsule by gas chromatography–mass spectrometry, of which 75 were identified by mass spectrometry in combination with the retention index. Then, a total of 124 components were tentatively identified by high‐performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. Fifteen constituents from Baidianling Capsule were accurately identified by comparing the retention times with those of reference compounds, others were identified by comparing the retention times and mass spectrometry data, as well as retrieving the reference literature. This study provides a practical strategy for rapidly screening and identifying the multiple constituents of a complex traditional Chinese medicine. 相似文献
2.
Liquid secondary ion mass spectrometry (L-SIMS) of six new functionalized macrocycles was investigated. All six compounds yielded abundant fragment ions and protonation molecular ions [M + H](+) under L-SIMS conditions. The proposed fragmentation mechanisms were supported by high-resolution accurate mass data from Fourier transform ion cyclotron resonance mass spectrometric and MS(n) experiments on using sustained off-resonance irradiation collision-induced dissociation. 相似文献
3.
Metabolomics approach for determining growth-specific metabolites based on Fourier transform ion cyclotron resonance mass spectrometry 总被引:2,自引:0,他引:2
Takahashi H Kai K Shinbo Y Tanaka K Ohta D Oshima T Altaf-Ul-Amin M Kurokawa K Ogasawara N Kanaya S 《Analytical and bioanalytical chemistry》2008,391(8):2769-2782
Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR/MS) is the best MS technology for obtaining exact mass
measurements owing to its great resolution and accuracy, and several outstanding FT-ICR/MS-based metabolomics approaches have
been reported. A reliable annotation scheme is needed to deal with direct-infusion FT-ICR/MS metabolic profiling. Correlation
analyses can help us not only uncover relations between the ions but also annotate the ions originated from identical metabolites
(metabolite derivative ions). In the present study, we propose a procedure for metabolite annotation on direct-infusion FT-ICR/MS
by taking into consideration the classification of metabolite-derived ions using correlation analyses. Integrated analysis
based on information of isotope relations, fragmentation patterns by MS/MS analysis, co-occurring metabolites, and database
searches (KNApSAcK and KEGG) can make it possible to annotate ions as metabolites and estimate cellular conditions based on
metabolite composition. A total of 220 detected ions were classified into 174 metabolite derivative groups and 72 ions were
assigned to candidate metabolites in the present work. Finally, metabolic profiling has been able to distinguish between the
growth stages with the aid of PCA. The constructed model using PLS regression for OD600 values as a function of metabolic profiles is very useful for identifying to what degree the ions contribute to the growth
stages. Ten phospholipids which largely influence the constructed model are highly abundant in the cells. Our analyses reveal
that global modification of those phospholipids occurs as E. coli enters the stationary phase. Thus, the integrated approach involving correlation analyses, metabolic profiling, and database
searching is efficient for high-throughput metabolomics.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
4.
Dong Cao Huogao Huang Ming Hu Lin Cui Fanglan Geng Ziyu Rao Hongyun Niu Yaqi Cai Yuehui Kang 《Analytica chimica acta》2015
Natural organic matter (NOM) is a complex and non-uniform mixture of organic compounds which plays an important role in environmental processes. Due to the complexity, it is challenging to obtain fully detailed structural information about NOM. Although Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) has been demonstrated to be a powerful tool for providing molecular information about NOM, multiple ionization methods are needed for comprehensive characterization of NOM at the molecular level considering the ionizing selectivity of different ionization methods. This paper reports the first use of matrix assisted laser desorption/ionization (MALDI) method coupled with FT-ICR-MS for molecular characterization of NOM within a mass range of 200–800 Da. The mass spectral data obtained by MALDI were systematically compared with data generated by electrospray ionization (ESI). It showed that complementary molecular information about NOM which could not be detected by ESI, were provided by MALDI. More unsaturated and aromatic constituents of NOM with lower O/C ratio (O/C ratio < 0.5) were preferentially ionized in MALDI negative mode, whereas more polar constituents of NOM with higher O/C ratio were preferentially ionized in ESI negative mode. Molecular anions of NOM appearing at even m/z in MALDI negative ion mode were detected. The results show that NOM molecules with aromatic structures, moderate O/C ratio (0.7 > O/C ratio > 0.25) and lower H/C ratio were liable to form molecular anions at even m/z, whereas those with higher H/C ratio are more likely to form deprotonated ions at odd m/z. It is speculated that almost half of the NOM molecules identified by MALDI may be aromatic or condensed aromatic compounds with special groups which are liable to absorb electron from other molecules to generate free radical anions during MALDI ionization. 相似文献
5.
Ziyun Wei Xiaomin Yu Yu Zhang Yanan Wang Haotian Zhang Sijie Wang Zan Zhang Wenwen Sui Xin Zhang Fei Han 《Journal of separation science》2022,45(2):477-491
Alcoholic liver disease is currently the most clinically concerning liver disease, which occurs from chronic alcohol abuse. Flos Puerariae and Semen Hoveniae have been used to treat alcohol drinking excessively for thousands of years in China. In this study, the ethanol extract of the medicine pair was qualitatively and quantitatively analyzed by high-performance liquid chromatography and Fourier transform ion cyclotron resonance mass spectrometry. First, the high-performance liquid chromatography fingerprint was established to obtain the overall chromatographic data of its chemical constituents. Next, high-performance liquid chromatography-mass spectrometry was applied to identify its chemical constituents. Then, the characteristic constituents were simultaneously quantified by high-performance liquid chromatography. In addition, the chemical constituents that were absorbed into rat plasma were identified by high-performance liquid chromatography-mass spectrometry. As a result, a total of 48 chemical constituents in the medicine pair were detected and identified in vitro. Meanwhile, the content of seven representative constituents, including dihydromyricetin, glycitin, genistin, tectoridin, glycitein, genistein, and tectorigenin were simultaneously determined. Furthermore, a total of 19 chemical constituents were detected in rat plasma after oral administration. In short, the chemical constituents of the medicine pair were initially investigated in this study, which will lay the foundation for the discovery of its pharmacodynamic substances in further works. 相似文献
6.
The analysis of sulfur aromatics in vacuum gas oils (VGO) distilled from an Iranian light crude oil is discussed. The VGOs
were fractionated into three boiling ranges, 390–460, 460–520, and 520–550 °C, and were analyzed using liquid chromatographic
separation on a Pd(II)-bonded stationary phase followed by identification with electrospray ionization Fourier transform ion
cyclotron resonance mass spectrometry (FT-ICR MS). It was possible to detect a large number of thiophenes, including a substantial
number of isomers, in the three VGO fractions. Separation on the palladium phase and inclusion of sulfur-selective derivatization
makes electrospray ionization of these nonpolar compounds possible. An elemental composition can be assigned to a large number
of S1 compounds without ambiguity in the presence of abundant hydrocarbons. With an increase in boiling temperature, an increase
in the size of the aromatic system and the number of side chain carbon atoms was observed. In addition, the masses of higher
magnitude shifted toward larger aromatic systems with an increase in boiling range. A comparison of FT-ICR MS and comprehensive
gas chromatography is also given.
This work is dedicated to Prof. B. Krebs on the occasion of his 70th birthday. 相似文献
7.
《Journal of separation science》2018,41(3):774-788
In this study, a reliable and sensitive ultra‐high performance liquid chromatography coupled with fourier transform ion cyclotron resonance mass spectrometry method was developed for the systematic study of the metabolic profile of Kudiezi injection in rat plasma, bile, urine, and feces after intravenous administration of a single dose. The chromatographic separation was performed on an Agilent Eclipse Plus C18 column (4.6 mm × 50 mm, 1.8 μm) and the identification of prototype components and metabolites was achieved on a Bruker Solarix 7.0 T ultra‐high resolution spectrometer in negative ion mode. Results indicated that a total of 76 constituents including 29 prototype compounds and 47 metabolites (10 phase I metabolites and 37 phase II metabolites) were tentatively identified. And the metabolic pathways of these prototype compounds including hydroxylation, dehydrogenation, glucuronidation, and sulfate conjugation. In conclusion, the developed method with high resolution and sensitivity was effective for screening and identification of prototypes and metabolites of Kudiezi injection in vivo. Moreover, these results would provide significant information for further pharmacokinetic and pharmacological research of Kudiezi injection in vivo. 相似文献
8.
Guo X Duursma MC Kistemaker PG Nibbering NM Vekey K Drahos L Heeren RM 《Journal of mass spectrometry : JMS》2003,38(6):597-606
The internal energy of protonated leucine enkephalin has been manipulated in electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry with two newly designed pump-probe experiments. Blackbody infrared radiation was applied to pump an ion population into a well-defined internal energy distribution below the dissociation threshold. Following this pumping stage, the internal energy distribution was probed using on-resonance collisional activation to dissociate the ions. These pump-probe experiments were carried out in two different ways: (a) using on-resonance collisional activation with variable kinetic energies to dissociate the ions at a constant initial ion temperature (determining the precursor ion survival percentage as a function of kinetic energy) and (b) using on-resonance collisional activation with a constant kinetic energy to dissociate the ions at variable initial ion temperatures (to investigate the ion survival yield-initial ion temperature dependence). Using this approach, a detailed study of the effects of the initial ion temperature, the probing kinetic energy and the internal energy loss rate on the effective conversion efficiency of (laboratory-frame) kinetic energy to internal energy was conducted. This conversion efficiency was found to be dependent on the initial ion temperature. Depending on the experimental conditions the conversion efficiency (for collisions with argon) was estimated to be about 4.0 +/- 1.7%, which agrees with that obtained from a theoretical modeling. Finally, the reconstructed curves of the ion survival yield versus the mode of the (final) total internal energy distribution of the activated ion population (after pump and probe events) at different pump-probe conditions reveal the internal energy content of the activated ions. 相似文献
9.
Ulli M. Hohenester Pierre Barbier Saint‐Hilaire Franois Fenaille Richard B. Cole 《Journal of mass spectrometry : JMS》2020,55(10)
Ultra‐high‐resolution mass spectrometry, in the absence of chromatography, is finding its place for direct analyses of highly complex mixtures, such as those encountered during untargeted metabolomics screening. Advances, however, have been tempered by difficulties such as uneven signal suppression experienced during electrospray ionization. Moreover, ultra‐high‐resolution mass spectrometers that use Orbitrap and ICR analyzers both suffer from limited ion trapping capacities, owing principally to space‐charge effects. This study has evaluated and contrasted the above two types of Fourier transform mass spectrometers for their abilities to detect and identify by accurate mass measurement, small molecule metabolites present in complex mixtures. For these direct introduction studies, the Orbitrap Fusion showed a major advantage in terms of speed of analysis, enabling detection of 218 of 440 molecules (<2 ppm error, 500 000 resolution at m/z 200) present in a complex mixture in 5 min. This approach is the most viable for high‐throughput workflows, such as those used in investigations involving very large cohorts of metabolomics samples. From the same mixture, 183 unique molecules were observed by FT‐ICR in the broadband mode, but this number was raised to 235 when “selected ion monitoring‐stitching” (SIM‐stitching) was employed (<0.1 ppm error, 7 T magnet with dynamic harmonization cell, 1.8 million resolution at m/z 200, both cases). SIM‐stitching FT‐ICR thus offered the most complete detection, which may be of paramount importance in situations where it is essential to obtain the most complete metabolic profile possible. This added completeness, however, came at the cost of a more lengthy analysis time (120 min including manual treatment). Compared to the data presented here, future automation of processing, plus the use of absorption mode detection, segmented ion detection (stepwise detection of smaller width m/z sections), and higher magnetic field strengths, can substantially reduce FT‐ICR acquisition times. 相似文献
10.
Paulo J. Amorim Madeira M. Helena Florêncio 《Journal of mass spectrometry : JMS》2009,44(7):1105-1113
The behaviour of 2,5‐dihydroxybenzoic acid (2,5‐DHB) matrix under matrix‐assisted laser desorption/ionisation (MALDI) conditions was investigated, and the formation of 2,5‐DHB cluster ions, mainly dehydrated 2,5‐DHB ions, is reported. Interestingly, in the mass spectra of this compound, besides dimers and trimers, protonated tetramers, pentamers, hexamers and heptamers were also found with significant abundance. The MALDI behaviour of four flavonoids, quercetin, myricetin, luteolin and kaempferol, using 2,5‐DHB as matrix, was also investigated. The mass spectra of the flavonoids studied revealed a number of flavonoid–2,5‐DHB cluster ions (mainly with the dehydrated 2,5‐DHB). The number of clusters formed is dependent on the structure of the analyte. For luteolin and kaempferol, in particular, evidence was found for the formation of cluster ions involving retro Diels Alder fragments and intact flavonoids molecules, as well as the corresponding protonated retro Diels Alder fragments with dehydrated DHB molecules. All ion compositions were attributed taking into account high accuracy mass measurements and tandem mass spectrometry experiments. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
11.
Covalent adduction of the model protein apomyoglobin by 4-hydroxy-2-nonenal, a reactive end-product of lipid peroxidation,
was characterized by nanoelectrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FTICR). The
high mass resolving power and mass measurement accuracy of the instrument facilitated a detailed compositional analysis of
the complex reaction product without the need for deconvolution and transformation to clearly show the pattern of adduction
and component molecular weights. Our study has also demonstrated the value of electron capture dissociation over collision-induced
dissociation for the tandem mass spectrometric determination of site modification for the 4-hydroxy-2-nonenal adduct of oxidized
insulin B chain as an example.
Figure FTICR allowed characterization of 4-hydroxy-2-nonenal (HNE)-modified apomyoglobin (an expanded spectrum of the +15 charge
state is shown) 相似文献
12.
Tsybin YO Ramström M Witt M Baykut G Håkansson P 《Journal of mass spectrometry : JMS》2004,39(7):719-729
The analytical utility of the electron capture dissociation (ECD) technique, developed by McLafferty and co-workers, has substantially improved peptide and protein characterization using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The limitations of the first ECD implementations on commercial instruments were eliminated by the employment of low-energy electron-injection systems based on indirectly heated dispenser cathodes. In particular, the ECD rate and reliability were greatly increased, enabling the combination of ECD/FTICR-MS with on-line liquid separation techniques. Further technique development allowed the combination of two rapid fragmentation techniques, high-rate ECD and infrared multiphoton dissociation (IRMPD), in a single experimental configuration. Simultaneous and consecutive irradiations of trapped ions with electrons and photons extended the possibilities for ion activation/dissociation and led to improved peptide and protein characterization. The application of high-rate ECD/FTICR-MS has demonstrated its power and unique capabilities in top-down sequencing of peptides and proteins, including characterization of post-translational modifications, improved sequencing of peptides with multiple disulfide bridges and secondary fragmentation (w-ion formation). Analysis of peptide mixtures has been accomplished using high-rate ECD in bottom-up mass spectrometry based on mixture separation by liquid chromatography and capillary electrophoresis. This paper summarizes the current impact of high-rate ECD/FTICR-MS for top-down and bottom-up mass spectrometry of peptides and proteins. 相似文献
13.
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15.
The electrospray ionization ion trap multiple-stage tandem mass spectrometry (ESI-MSn) and electrospray ionization Fourier transform ion cyclotron resonance multiple-stage tandem mass spectrometry (ESI-FT-ICR-MSn) have been applied successfully to the direct investigation of a number of dibenzocyclooctadiene lignan constituents from the methanol extracts of the Fructus Schisandrae in the positive ion mode. The detailed structural characterization of the same skeleton and different peripheral substituents had been studied and the precise elemental compositions of ions at high mass resolution had been obtained. So the fragmentation mechanisms could be clarified. And the lignan components in Schisandra chinensis (Turcz.) Baill. fruits (SCF) and Schisandra sphenanthera Rehd. et Wils. fruits (SSF) were identified by comparing the structural information and fragmentation mechanisms. Then a pair of isobaric compounds was differentiated. Meanwhile these two similar fruits were distinguished. The research results demonstrated that ESI-MSn technique is a sensitive, selective and effective tool for the direct analysis and rapid determination of constituents in complex mixtures from nature products. And these should be useful for the identification of similar compounds and differentiation of similar species from Chinese herbs. 相似文献
16.
John Hanna El‐Nakat Noha Ghanem Paolo Yammine Gary Willett Keith Fisher 《International journal of quantum chemistry》2007,107(6):1367-1372
Fourier transform ion cyclotron resonance mass spectrometry (FT‐ICR/MS) offers the opportunity for gas phase cluster formation reactions at very low pressures and at temperatures that are different from room temperature. Reactions take place with single positive‐charge metal ions that are normally +2, +3, +4, etc., charged in solution. The ions formed are detected by measuring the current induced by their cyclotron rotation, but they cannot be physically separated and collected. Collision‐induced dissociation (CID) is widely used for ion‐structure determination via the fragmentation of the excited ions. CID study aims to determine the relationship between the Vpp [peak‐to‐peak voltage of the radiofrequency (rf) pulse] and the mass‐to‐charge (m/z) ratio, which will be used for the calculation of the center‐of‐mass translational kinetic energy (Ekcm) of the excited ion under investigation. CID studies are restricted to stable ions with relatively high abundance. Nevertheless, with the evolution of computational chemistry, such problems can be overcome whereby CID calculations will be used to provide the substantial parameters for computer software, such as the Gaussian 03 program, for the structure determination of the less stable NixS anions. The latter constitutes the core for our current research. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 相似文献
17.
Gang Li Zhongbin Huang Chuan Fu Pengxiang Xu Yan Liu Yu‐fen Zhao 《Journal of mass spectrometry : JMS》2010,45(6):643-650
The binary mixtures of 7 hexoses and 20 amino acids were investigated by electrospray ionization ion trap mass spectrometry (ESI‐ITMS). The adduct ions of the amino acid and the hexose were detected for 12 amino acids but not for the other 8 amino acids which are basic acidic amino acids and amides. The ions of amino acid–hexose complexes were further investigated by tandem mass spectrometry (MS/MS), and some of them just split easily into two parts whereas the others gave rich fragmentation, such as the complex ions of isoleucine, phenylalanie, tyrosine, and valine. We found that hexoses could be complexed by two molecules of valine but only by one molecule of the other amino acids. Among seven kinds of valine–hexose complexes coordinated by potassium ion, the MS2 spectra of the ion at m/z 453 yielded unambiguous differentiation. And the fragmentation ions are sensitive to the stereochemical differences at the carbon‐4 of hexoses in the complexes, as proved by the MS2. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
18.
Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS) was used to investigate metal ion interactions of the 18 amino acid peptide fragment B18 (LGLLLRHLRHHSNLLANI), derived from the membrane-associated protein bindin. The peptide sequence B18 represents the minimal membrane-binding motif of bindin and resembles a putative fusion peptide. The histidine-rich peptide has been shown to self-associate into distinct supramolecular structures, depending on the presence of Zn(2+) and Cu(2+). We examined the binding of B18 to the metal ions Cu(2+), Zn(2+), Mg(2+), Ca(2+), Mn(2+) and La(3+). For Cu(2+), we compared the metal binding affinities of the wild-type B18 peptide with those of its mutants in which one, two or three histidine residues have been replaced by serines. Upon titration of B18 with Cu(2+) ions, we found sequential binding of two Cu(2+) ions with dissociation constants of approximately 34 and approximately 725 micro M. Mutants of B18, in which one histidine residue is replaced by serine, still exhibit sequential binding of two copper ions with affinities for the first Cu(2+) ion comparable to that of wild-type B18 peptide, but with a greatly reduced affinity for the second Cu(2+) ion in mutants H112S and H113S. For mutants in which two histidines are replaced by serines, the affinity for the first Cu(2+) ion is reduced approximately 3-10 times in comparison with B18. The mutant in which all three histidine residues are replaced by serines exhibits an approximately 14-fold lower binding for the first Cu(2+) ion compared with B18. For the other metal ions under investigation (Zn(2+), Mg(2+), Ca(2+), Mn(2+) and La(3+)), a modest affinity to B18 was detected binding to the peptide in a 1 : 1 stoichiometry. Our results show a high affinity of the wild-type fusogenic peptide B18 for Cu(2+) ions whereas the Zn(2+) affinity was found to be comparable to that of other di- and trivalent metal ions. 相似文献
19.
Rapid characterization of the chemical constituents of Cortex Fraxini by homogenate extraction followed by UHPLC coupled with Fourier transform ion cyclotron resonance mass spectrometry and GC–MS 下载免费PDF全文
Yinan Wang Fei Han Aihua Song Miao Wang Chunjie Zhao 《Journal of separation science》2016,39(22):4325-4334
Cortex Fraxini is an important traditional Chinese medicine. In this work, a rapid and reliable homogenate extraction method was applied for the fast extraction for Cortex Fraxini, and the method was optimized by response surface methodology. Ultra high performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry and gas chromatography with mass spectrometry were established for the separation and characterization of the constituents of Cortex Fraxini. Liquid chromatography separation was conducted on a C18 column (150 mm × 2.1 mm, 1.8 μm), and gas chromatography separation was performed on a capillary with a 5% phenyl‐methylpolysiloxane stationary phase (30 m × 0.25 mm × 0.25 mm) by injection of silylated samples. According to the results, 33 chemical compounds were characterized by liquid chromatography with mass spectrometry, and 11 chemical compounds were characterized by gas chromatography with mass spectrometry, and coumarins were the major components characterized by both gas chromatography with mass spectrometry and liquid chromatography with mass spectrometry. The proposed homogenate extraction was an efficient and rapid method, and coumarins, phenylethanoid glycosides, iridoid glycosides, phenylpropanoids, and lignans were the main constituents of Cortex Fraxini. This work laid the foundation for further study of Cortex Fraxini and will be helpful for the rapid extraction and characterization of ingredients in other traditional Chinese medicines. 相似文献
20.
Bai Y Galetskiy D Damoc E Ripper J Woischnik M Griese M Liu Z Liu S Przybylski M 《Analytical and bioanalytical chemistry》2007,389(4):1075-1085
High-resolution Fourier transform ion cyclotron resonance (FTICR) mass spectrometry was developed and applied to the proteome
analysis of bronchoalveolar lavage fluid (BALF) from a patient with pulmonary alveolar proteinosis. With use of 1-D and 2-D
gel electrophoresis, surfactant protein A (SP-A) and other surfactant-related lung alveolar proteins were efficiently separated
and identified by matrix-assisted laser desorption/ionization FTICR mass spectrometry . Low molecular mass BALF proteins were
separated using a gradient 2-D gel. An efficient extraction/precipitation system was developed and used for the enrichment
of surfactant proteins. The result of the BALF proteome analysis show the presence of several isoforms of SP-A, in which an
N-non-glycosylierte form and several proline hydroxylations were identified. Furthermore, a number of protein spots were found
to contain a mixture of proteins unresolved by 2-D gel electrophoresis, illustrating the feasibility of high-resolution mass
spectrometry to provide identifications of proteins that remain unseparated in 2-D gels even upon extended pH gradients.
Yu Bai and Dmitry Galetskiy both contributed equally to this work. 相似文献