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Hu J, Chen C, Zhou H, Zhang L, Yan S, Liang H. Investigation of unexpected silane ions caused by gas-phase reactions in Orbitrap gas chromatography-mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2024; 38:e9740. [PMID: 38567573 DOI: 10.1002/rcm.9740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/04/2024] [Accepted: 02/27/2024] [Indexed: 04/04/2024]
Abstract
RATIONALE The mass spectra of compounds containing dimethyl (phenyl)silyl group (-SiMe2Ph) sometimes exhibit unusual ion peaks when measured using Orbitrap gas chromatography-mass spectrometry (GC-MS). This would complicate the mass spectra and may limit the matching of spectral data with preexisting resources for compound annotation. These peaks were identified as products from reactions with residual water. METHODS A series of dimethyl (phenyl)silyl compounds were dissolved in methanol and investigated using Orbitrap GC-MS. Certain ions reacted with residual water in the C-trap. The reaction was confirmed using accurate mass and elemental composition analysis via MS studies, and the active center of the reaction was determined using density functional theory (DFT) calculations. RESULTS Two types of gas-phase reactions between gaseous water and cations from a series of silanes were identified. DFT calculations indicate that silicon (Si) acts as the active center for these gas-phase water reactions. Compounds with multiple Si atoms generate a larger number of additional ions, which would complicate the mass spectra. The mass spectra of vinylsilanes and alkylsilanes with -SiMe2Ph indicate that the conjugated group linked to -SiMe2Ph can affect the water adduction process. CONCLUSIONS Silane ions could react with residual water in the C-trap of an Orbitrap mass spectrometer. The mass spectra of these compounds may exhibit unexplained peaks arising from gas-phase reactions. Although these reactions may decrease spectral matching scores for compound annotation, they offer opportunities for systematic investigations into the mechanistic and kinetic aspects of high-energy ion reactivity.
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Affiliation(s)
- Jingxin Hu
- School of Chemistry, Sun Yat-sen University, Guangzhou, China
- Instrumental Analysis & Research Center, Sun Yat-sen University, Guangzhou, China
| | - Chunying Chen
- School of Chemistry, Sun Yat-sen University, Guangzhou, China
| | - Haiyun Zhou
- Instrumental Analysis & Research Center, Sun Yat-sen University, Guangzhou, China
| | - Li Zhang
- School of Chemistry, Sun Yat-sen University, Guangzhou, China
| | - Sujun Yan
- Instrumental Analysis & Research Center, Sun Yat-sen University, Guangzhou, China
| | - Hui Liang
- School of Chemistry, Sun Yat-sen University, Guangzhou, China
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Tavares EDA, Guerra GCB, da Costa Melo NM, Dantas-Medeiros R, da Silva ECS, Andrade AWL, de Souza Araújo DF, da Silva VC, Zanatta AC, de Carvalho TG, de Araújo AA, de Araújo-Júnior RF, Zucolotto SM. Toxicity and Anti-Inflammatory Activity of Phenolic-Rich Extract from Nopalea cochenillifera (Cactaceae): A Preclinical Study on the Prevention of Inflammatory Bowel Diseases. PLANTS (BASEL, SWITZERLAND) 2023; 12:594. [PMID: 36771677 PMCID: PMC9921826 DOI: 10.3390/plants12030594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/04/2023] [Accepted: 01/11/2023] [Indexed: 06/18/2023]
Abstract
Phenolic compounds have been scientifically recognized as beneficial to intestinal health. The cactus Nopalea cochenillifera, used as anti-inflammatory in traditional medicine, is a rich source of these bioactive compounds. The present study aimed to investigate the phytochemical profile of N. cochenillifera extract and evaluate its acute toxicity and anti-inflammatory effect on 2,4-dinitrobenzenesulfonic acid (DNBS)-induced colitis in rats. The total phenolic content per gram of dry extract was 67.85 mg. Through HPLC-IES-MSn, a total of 25 compounds such as saccharides, organic acids, phenolic acids and flavonoids were characterized. The dose of 2000 mg/kg of extract by an oral route showed no signs of toxicity, mortality or significant changes in biochemical and hematological parameters. Regarding intestinal anti-inflammatory effects, animals were treated with three different doses of extract or sulfasalazine. Macroscopic analysis of the colon indicated that the extract decreased the disease activity index. Levels of IL-1β and TNF-α decreased, IL-10 increased and MDA and MPO enzyme levels decreased when compared with the control group. In addition, a down-regulation of MAPK1/ERK2 and NF-κB p65 pathway markers in colon tissue was observed. The epithelial integrity was improved according to histopathological and immunohistological analysis. Thus, the extract provided strong preclinical evidence of being effective in maintaining the remission of colitis.
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Affiliation(s)
- Emanuella de Aragão Tavares
- Graduate Program in Drug Development and Technological Innovation, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
| | - Gerlane Coelho Bernardo Guerra
- Graduate Program in Drug Development and Technological Innovation, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
- Department of Biophysics and Pharmacology, Biosciences Center, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
- Graduate Program in Pharmaceutical Science, Federal University of Rio Grande do Norte (UFRN), Natal 59078-970, Brazil
| | - Nadja Maria da Costa Melo
- Graduate Program in Drug Development and Technological Innovation, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
| | - Renato Dantas-Medeiros
- Graduate Program in Drug Development and Technological Innovation, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
| | | | - Anderson Wilbur Lopes Andrade
- Graduate Program in Drug Development and Technological Innovation, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
| | | | - Valéria Costa da Silva
- Graduate Program in Drug Development and Technological Innovation, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
| | - Ana Caroline Zanatta
- Department of Biomolecular Sciences, Faculty of Pharmaceutical Sciences of Ribeirão Preto, São Paulo University, São Paulo, Ribeirão Preto 14040-903, Brazil
| | - Thaís Gomes de Carvalho
- Program Degree in Health Science, Federal University of Rio Grande do Norte (UFRN), Natal 59078-970, Brazil
| | - Aurigena Antunes de Araújo
- Department of Biophysics and Pharmacology, Biosciences Center, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
- Graduate Program in Pharmaceutical Science, Federal University of Rio Grande do Norte (UFRN), Natal 59078-970, Brazil
- Program Degree in Health Science, Federal University of Rio Grande do Norte (UFRN), Natal 59078-970, Brazil
| | - Raimundo Fernandes de Araújo-Júnior
- Graduate Program in Drug Development and Technological Innovation, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
- Program Degree in Health Science, Federal University of Rio Grande do Norte (UFRN), Natal 59078-970, Brazil
- Cancer and Inflammation Research Laboratory, Morphology Department, Biosciences Center, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
| | - Silvana Maria Zucolotto
- Graduate Program in Drug Development and Technological Innovation, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil
- Graduate Program in Pharmaceutical Science, Federal University of Rio Grande do Norte (UFRN), Natal 59078-970, Brazil
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Ding X, Kumar M, Zheng Z, Lee A, Hopkins WS, Attygalle AB. Evidence of Gas-Phase Attachment of Molecular Oxygen to Deprotonated Hydroquinone During Ion-Mobility Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1816-1824. [PMID: 36129840 DOI: 10.1021/jasms.1c00222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Gas-phase addition of dioxygen to certain ions is a well-known phenomenon in mass spectrometry. For this reaction to occur, the presence of a distonic radical site on the precursor ion is thought to be a prerequisite. Herein, we report that oxygen adduct formation can take place also with deprotonated hydroquinone, which in fact is an even-electron species without a radical site. When the product-ion spectrum of the m/z 109 ion, generated by electrospray ionization from a solution of hydroquinone in acetonitrile, was recorded under ion-mobility conditions, a new peak was observed at m/z 141. However, an analogous peak was not visible in the spectrum acquired under nonmobility conditions (i.e., without any gas introduced to the mobility cell). Presumably, traces of oxygen present in the collision gas instigate an ion-molecule reaction to produce an adduct of m/z 141, which upon activation results in CO and H2O loss to form a product ion of m/z 95. Isotope-labeling studies confirmed that one of the hydrogen atoms from the hydroxy group and another from the aromatic ring contribute to the water loss instigated from the m/z 141 adduct. Furthermore, computational methods indicated the three-dimensional structure of the ground-state deprotonated hydroquinone to be distinctly different from those of its 1,2- and 1,3-isomers. Calculations predicted that all atoms in the two m/z 109 ions generated from catechol and resorcinol lie on one plane. In contrast, the structure of the m/z 109 ion from hydroquinone was significantly different. Computations predicted that the hydrogen atom on the intact hydroxyl group of deprotonated hydroquinone protrudes out of plane from rest of the atoms. Consequently, the exposed OH group can interact with an incoming dioxygen molecule. Computations conducted at the CAM-B3LYP/6-311++g(2d,2p) level of theory detected a minimum energy crossing point (MECP) at -4.3 kJ mol-1 below the separated O2 + deprotonated hydroquinone triplet threshold. In contrast, similar calculations conducted for catechol and resorcinol yielded MECPs of +116.9 and +69.1 kJ mol-1, respectively, above the associated triplet thresholds. These results indicated that the curve crossing required to form singlet products upon reaction with triplet O2 is favorable in the case of hydroquinone and unfavorable in the cases of catechol and resorcinol. In practical terms, the selective oxygen addition appears to be a diagnostically useful reaction to differentiate hydroquinone from its ring isomers.
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Affiliation(s)
- Xiao Ding
- Center for Mass Spectrometry, Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Meenu Kumar
- Center for Mass Spectrometry, Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Zhaoyu Zheng
- Center for Mass Spectrometry, Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Arthur Lee
- Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - W Scott Hopkins
- Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Athula B Attygalle
- Center for Mass Spectrometry, Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
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Stochastic dynamic quantitative and 3D structural matrix assisted laser desorption/ionization mass spectrometric analyses of mixture of nucleosides. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.132701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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5
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Wang Y, Xie H, Alugubelli YR, Ma Y, Xu S, Ma J, Liu WR, Liang D. Accurate Mass Identification of an Interfering Water Adduct and Strategies in Development and Validation of an LC-MS/MS Method for Quantification of MPI8, a Potent SARS-CoV-2 Main Protease Inhibitor, in Rat Plasma in Pharmacokinetic Studies. Pharmaceuticals (Basel) 2022; 15:ph15060676. [PMID: 35745595 PMCID: PMC9228185 DOI: 10.3390/ph15060676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/17/2022] [Accepted: 05/23/2022] [Indexed: 12/04/2022] Open
Abstract
MPI8, a peptidyl aldehyde, is a potent antiviral agent against coronavirus. Due to unique tri-peptide bonds and the formyl functional group, the bioassay of MPI8 in plasma was challenged by a strong interference from water MPI8. Using QTOF LC-MS/MS, we identified MPI8•H2O as the major interference form that co-existed with MPI8 in aqueous and biological media. To avoid the resolution of MPI8 and MPI8•H2O observed on reverse phase columns, we found that a Kinetex hydrophilic interaction liquid chromatography (HILIC) column provided co-elution of both MPI8 and MPI8•H2O with a good single chromatographic peak and column retention of MPI8 which is suitable for quantification. Thus, a sensitive, specific, and reproducible LC-MS/MS method for the quantification of MPI8 in rat plasma was developed and validated using a triple QUAD LC-MS/MS. The chromatographic separation was achieved on a Kinetex HILIC column with a flow rate of 0.4 mL/min under gradient elution. The calibration curves were linear (r2 > 0.99) over MPI8 concentrations from 0.5−500 ng/mL. The accuracy and precision are within acceptable guidance levels. The mean matrix effect and recovery were 139% and 73%, respectively. No significant degradation of MPI8 occurred under the experimental conditions. The method was successfully applied to a pharmacokinetic study of MPI8 after administration of MPI8 sulfonate in rats.
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Affiliation(s)
- Yang Wang
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004, USA; (Y.W.); (H.X.); (J.M.)
| | - Huan Xie
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004, USA; (Y.W.); (H.X.); (J.M.)
| | - Yugendar R. Alugubelli
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA; (Y.R.A.); (Y.M.); (S.X.)
| | - Yuying Ma
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA; (Y.R.A.); (Y.M.); (S.X.)
| | - Shiqing Xu
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA; (Y.R.A.); (Y.M.); (S.X.)
| | - Jing Ma
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004, USA; (Y.W.); (H.X.); (J.M.)
| | - Wenshe R. Liu
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA; (Y.R.A.); (Y.M.); (S.X.)
- Correspondence: (W.R.L.); (D.L.); Tel.: +1-979-845-1746 (W.R.L.); +1-713-313-1885 (D.L.)
| | - Dong Liang
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004, USA; (Y.W.); (H.X.); (J.M.)
- Correspondence: (W.R.L.); (D.L.); Tel.: +1-979-845-1746 (W.R.L.); +1-713-313-1885 (D.L.)
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Kreidl M, Rainer M, Bonn GK, Oberacher H. Electrochemical Simulation of the Oxidative Capsaicin Metabolism. Chem Res Toxicol 2021; 34:2522-2533. [PMID: 34879203 DOI: 10.1021/acs.chemrestox.1c00288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Capsaicin, primarily known as the pungent ingredient in hot peppers, is rapidly metabolized in the human body by enzymatic processes altering the pharmacological as well as toxicological properties. Herein, the oxidative transformation of capsaicin was investigated in vitro with electrochemistry as well as human liver microsomal incubations. The reaction mixtures were analyzed with liquid chromatography-mass spectrometry. Structure elucidation involved accurate mass measurements and multistage tandem mass spectrometry experiments. In total, 126 transformation products were detected. Electrochemistry provided evidence for 101 transformation products and the microsomal incubations for 46 species. 21 compounds were observed with both approaches. Identified oxidative pathways likely occurring during the phase I metabolism included dehydrogenation, O-demethylation, and hydroxylation reactions as well as combinations thereof. Furthermore, trapping of reactive intermediates either with glutathione or with electrochemically activated ribonucleosides provided evidence for the possible production of phase II metabolites and covalent adducts with a genetic material. Evidence for the occurrence of some capsaicin metabolites in humans was obtained by urine screening.
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Affiliation(s)
- Marco Kreidl
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Matthias Rainer
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Günther K Bonn
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria.,ADSI-Austrian Drug Screening Institute GmbH, University of Innsbruck, Innrain 66a, 6020 Innsbruck, Austria
| | - Herbert Oberacher
- Institute of Legal Medicine and Core Facility Metabolomics, Medical University of Innsbruck, Muellerstrasse 44, 6020 Innsbruck, Austria
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Identification of New Markers of Alcohol-Derived DNA Damage in Humans. Biomolecules 2021; 11:biom11030366. [PMID: 33673538 PMCID: PMC7997542 DOI: 10.3390/biom11030366] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/16/2021] [Accepted: 02/21/2021] [Indexed: 12/13/2022] Open
Abstract
Alcohol consumption is a risk factor for the development of several cancers, including those of the head and neck and the esophagus. The underlying mechanisms of alcohol-induced carcinogenesis remain unclear; however, at these sites, alcohol-derived acetaldehyde seems to play a major role. By reacting with DNA, acetaldehyde generates covalent modifications (adducts) that can lead to mutations. Previous studies have shown a dose dependence between levels of a major acetaldehyde-derived DNA adduct and alcohol exposure in oral-cell DNA. The goal of this study was to optimize a mass spectrometry (MS)-based DNA adductomic approach to screen for all acetaldehyde-derived DNA adducts to more comprehensively characterize the genotoxic effects of acetaldehyde in humans. A high-resolution/-accurate-mass data-dependent constant-neutral-loss-MS3 methodology was developed to profile acetaldehyde-DNA adducts in purified DNA. This resulted in the identification of 22 DNA adducts. In addition to the expected N2-ethyldeoxyguanosine (after NaBH3CN reduction), two previously unreported adducts showed prominent signals in the mass spectra. MSn fragmentation spectra and accurate mass were used to hypothesize the structure of the two new adducts, which were then identified as N6-ethyldeoxyadenosine and N4-ethyldeoxycytidine by comparison with synthesized standards. These adducts were quantified in DNA isolated from oral cells collected from volunteers exposed to alcohol, revealing a significant increase after the exposure. In addition, 17 of the adducts identified in vitro were detected in these samples confirming our ability to more comprehensively characterize the DNA damage deriving from alcohol exposures.
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Frańska M, Stężycka O, Ławniczak Ł. Unusual gas-phase hydration efficiency of magnesium-adenosine complex. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e8982. [PMID: 33140450 DOI: 10.1002/rcm.8982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 10/11/2020] [Accepted: 10/15/2020] [Indexed: 06/11/2023]
Affiliation(s)
- Magdalena Frańska
- Institute of Chemistry and Technical Electrochemistry, Poznań University of Technology, Berdychowo 4, Poznań, 60-965, Poland
| | - Olga Stężycka
- Institute of Chemistry and Technical Electrochemistry, Poznań University of Technology, Berdychowo 4, Poznań, 60-965, Poland
| | - Łukasz Ławniczak
- Institute of Chemical Technology and Engineering, Poznań University of Technology, Berdychowo 4, Poznań, 60-965, Poland
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Cui Y, Yuan J, Wang P, Wu J, Yu Y, Wang Y. Collision-Induced Dissociation Studies of Protonated Ions of Alkylated Thymidine and 2'-Deoxyguanosine. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:927-937. [PMID: 32134268 PMCID: PMC7362892 DOI: 10.1021/jasms.9b00147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Mass spectrometry and tandem MS (MS/MS) have been widely employed for the identification and quantification of damaged nucleosides in DNA, including those induced by alkylating agents. Upon collisional activation, protonated ions of alkylated nucleosides frequently undergo facile neutral loss of a 2-deoxyribose in MS/MS, and further cleavage of the resulting protonated nucleobases in MS3 can sometimes be employed for differentiating regioisomeric alkylated DNA lesions. Herein, we investigated systematically the collision-induced dissociation (CID) of the protonated ions of O4-alkylthymidine (O4-alkyldT), O2-alkyldT, O6-alkyl-2'-deoxyguanosine (O6-alkyldG), and N2-alkyldG through MS3 analysis. The MS3 of O2- and O4-MedT exhibit different fragmentation patterns from each other and from other O2- and O4-alkyldT adducts carrying larger alkyl groups. Meanwhile, elimination of alkene via a six-membered ring transition state is the dominant fragmentation pathway for O2-alkyldT, O4-alkyldT, and O6-alkyldG adducts carrying larger alkyl groups, whereas O6-MedG mainly undergoes elimination of ammonia. The breakdown of N2-alkyldG is substantially influenced by the structure of the alkyl group, where the relative ease in eliminating ammonia and alkene is modulated by the chain length and branching of the alkyl groups. We also rationalize our observations with density functional theory (DFT) calculations.
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Errabelli R, Zheng Z, Attygalle AB. Formation of Protonated ortho-Quinonimide from ortho-Iodoaniline in the Gas Phase by a Molecular-Oxygen-Mediated, ortho-Isomer-Specific Fragmentation Mechanism. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:864-872. [PMID: 32233379 DOI: 10.1021/jasms.9b00108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Upon collisional activation under mass spectrometric conditions, protonated 2-, 3-, and 4-iodoanilines lose an iodine radical to generate primarily dehydroanilinium radical cations (m/z 93), which are the distonic counterparts of the conventional molecular ion of aniline. When briefly accumulated in the Trap region of a Triwave cell in a SYNAPT G2 instrument, before being released for ion-mobility separation, these dehydroanilinium cations react readily with traces of oxygen present in the mobility gas to form peroxyl radical cations. Although all three isomeric dehydroanilinium ions showed avid affinity for O2, their reactivities were distinctly different. For example, the product-ion spectra recorded from mass-selected m/z 93 ion from 3- and 4-iodoanilines showed a peak at m/z 125 for the respective peroxylbenzenaminium ion. In contrast, an analogous peak at m/z 125 was absent in the spectrum of the 2-dehydroanilinium ion generated from 2-iodoaniline. Evidently, the 2-peroxylbenzenaminium ion generated from the 2-dehydroanilinium ion immediately loses a •OH to form protonated ortho-quinonimide (m/z 108).
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Affiliation(s)
- Ramu Errabelli
- Center for Mass Spectrometry, Department of Chemistry, and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Zhaoyu Zheng
- Center for Mass Spectrometry, Department of Chemistry, and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Athula B Attygalle
- Center for Mass Spectrometry, Department of Chemistry, and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
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Jokipii Krueger CC, Madugundu G, Degner A, Patel Y, Stram DO, Church TR, Tretyakova N. Urinary N7-(1-hydroxy-3-buten-2-yl) guanine adducts in humans: temporal stability and association with smoking. Mutagenesis 2020; 35:19-26. [PMID: 31702786 PMCID: PMC7016204 DOI: 10.1093/mutage/gez030] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 09/13/2019] [Indexed: 12/24/2022] Open
Abstract
1,3-Butadiene (BD) is a known human carcinogen found in cigarette smoke, automobile exhaust, and urban air. Workers occupationally exposed to BD in the workplace have an increased incidence of leukemia and lymphoma. BD undergoes cytochrome P450-mediated metabolic activation to 3,4-epoxy-1-butene (EB), 1,2,3,4-diepoxybutane (DEB) and 1,2-dihydroxy-3,4-epoxybutane (EBD), which form covalent adducts with DNA. We have previously reported a quantitative nanoLC/ESI+-HRMS3 method for urinary N7-(1-hydroxy-3-buten-2-yl) guanine (EB-GII) adducts as a mechanism-based biomarker of BD exposure. In the present study, the method was updated to include high throughput 96-well solid phase extraction (SPE) and employed to establish urinary EB-GII biomarker stability and association with smoking. Urinary EB-GII levels were measured bimonthly for 1 year in 19 smokers to determine whether single adduct measurement provides reliable levels of EB-GII in an individual smoker. In addition, association of EB-GII with smoking was studied in 17 individuals participating in a smoking cessation program. EB-GII levels decreased 34% upon smoking cessation, indicating that it is associated with smoking status, but may also originate from sources other than exposure to cigarette smoke.
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Affiliation(s)
- Caitlin C Jokipii Krueger
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN
| | - Guru Madugundu
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN
| | - Amanda Degner
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN
| | - Yesha Patel
- Department of Preventative Medicine, School of Medicine, University of Southern California, Los Angeles, CA
| | - Daniel O Stram
- Department of Preventative Medicine, School of Medicine, University of Southern California, Los Angeles, CA
| | - Timothy R Church
- Division of Environmental Health Sciences, University of Minnesota School of Public Health, Minneapolis, MN
| | - Natalia Tretyakova
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN
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Chai Y, Wang L, Lu C. Formation of molecular oxygen- and water-attached fragment ions in the fragmentation of protonated 3-(phenylthio)chromones. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34:e8567. [PMID: 31469930 DOI: 10.1002/rcm.8567] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/16/2019] [Accepted: 08/26/2019] [Indexed: 06/10/2023]
Affiliation(s)
- Yunfeng Chai
- Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 South Meiling Road, Hangzhou, 310008, P.R. China
- Key Laboratory of Tea Quality and Safety Control, Ministry of Agriculture and Rural Affairs, 9 South Meiling Road, Hangzhou, 310008, P.R. China
| | - Lu Wang
- University of Hawaii Cancer Center, 701 Ilalo Street, Room 254, Honolulu, HI, 96813, USA
| | - Chengyin Lu
- Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 South Meiling Road, Hangzhou, 310008, P.R. China
- Key Laboratory of Tea Quality and Safety Control, Ministry of Agriculture and Rural Affairs, 9 South Meiling Road, Hangzhou, 310008, P.R. China
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Kosyakov DS, Khoroshev OY, Anikeenko EA, Ul’yanovskii NV. Quadrupole Ion Trap Time-of-Flight MALDI Mass Spectrometry: Hydration of Ions of Hydroxyl-Containing Compounds. JOURNAL OF ANALYTICAL CHEMISTRY 2019. [DOI: 10.1134/s1061934819140053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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14
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Tang Y, Zhang JL. Recent developments in DNA adduct analysis using liquid chromatography coupled with mass spectrometry. J Sep Sci 2019; 43:31-55. [PMID: 31573133 DOI: 10.1002/jssc.201900737] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/04/2019] [Accepted: 09/27/2019] [Indexed: 12/15/2022]
Abstract
The formation of DNA adducts by genotoxic agents is an early event in cancer development, and it may lead to gene mutations, thereby initiating tumor development. The measurement of DNA adducts can provide critical information about the genotoxic potential of a chemical and its mechanism of carcinogenesis. In recent decades, liquid chromatography coupled with mass spectrometry has become the most important technique for analyzing DNA adducts. The improvements in resolution achievable with new chromatographic separation techniques coupled with the high specificity and sensitivity and wide dynamic range of new mass spectrometry systems have been used for both qualitative and quantitative analyses of DNA adducts. This review discusses the challenges in qualitative and quantitative analyses of DNA adducts by liquid chromatography coupled with mass spectrometry and highlights recent developments towards overcoming the limitations of liquid chromatography coupled with mass spectrometry methods. The key steps and new solutions, such as sample preparation, mass spectrometry fragmentation, and method validation, are summarized. In addition, the fundamental principles and latest advances in DNA adductomic approaches are reviewed.
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Affiliation(s)
- Yu Tang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, P. R. China
| | - Jin-Lan Zhang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, P. R. China
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15
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Development and validation of a rapid LC–MS/MS method for determination of methylated nucleosides and nucleobases in urine. J Chromatogr B Analyt Technol Biomed Life Sci 2019; 1128:121775. [DOI: 10.1016/j.jchromb.2019.121775] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 08/12/2019] [Accepted: 08/20/2019] [Indexed: 12/11/2022]
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16
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Chai Y, Chen H, Liu X, Lu C. Formation of Carbon Dioxide Attached Fragment Ions in the Fragmentation of Deprotonated Tolfenpyrad and Tebufenpyrad. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2060-2067. [PMID: 31338738 DOI: 10.1007/s13361-019-02273-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/19/2019] [Accepted: 06/19/2019] [Indexed: 06/10/2023]
Abstract
The in-source collision-induced dissociation (CID) and MS/MS mass spectra of deprotonated tolfenpyrad and tebufenpyrad both showed an unusual fragment ion at m/z 187, but its fragmentation pattern and structure could not be explained by logical neutral losses. Accurate mass measurement indicated that the mass difference between this fragment ion and the dominant fragment ion at m/z 143 equaled to a carbon dioxide (CO2) molecule. The isolation of the fragment ion m/z 143 in the mass analyzer could spontaneously give rise to the ion m/z 187. The Gibbs free energy of carbon dioxide addition to deprotonated pyrazole ion was significantly negative from the computational results. According to these results, we derived a proposal for the formation and structure of the ion m/z 187, which was an attachment of molecular carbon dioxide to the fragment ion m/z 143 to produce a carboxylate anion. The trace carbon dioxide was speculated to be derived from the residual atmosphere or collision gas in the instrument. This study is valuable for the qualitative and quantitative mass spectrometry analysis of pesticides containing the pyrazole functional group.
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Affiliation(s)
- Yunfeng Chai
- Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 South Meiling Road, Hangzhou, 310008, People's Republic of China
- Key Laboratory of Tea Quality and Safety Control, Ministry of Agriculture and Rural Affairs, 9 South Meiling Road, Hangzhou, 310008, People's Republic of China
- Laboratory of Quality and Safety Risk Assessment for Tea Products (Hangzhou), Ministry of Agriculture and Rural Affairs, 9 South Meiling Road, Hangzhou, 310008, People's Republic of China
| | - Hongping Chen
- Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 South Meiling Road, Hangzhou, 310008, People's Republic of China
- Key Laboratory of Tea Quality and Safety Control, Ministry of Agriculture and Rural Affairs, 9 South Meiling Road, Hangzhou, 310008, People's Republic of China
- Laboratory of Quality and Safety Risk Assessment for Tea Products (Hangzhou), Ministry of Agriculture and Rural Affairs, 9 South Meiling Road, Hangzhou, 310008, People's Republic of China
| | - Xin Liu
- Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 South Meiling Road, Hangzhou, 310008, People's Republic of China.
- Key Laboratory of Tea Quality and Safety Control, Ministry of Agriculture and Rural Affairs, 9 South Meiling Road, Hangzhou, 310008, People's Republic of China.
- Laboratory of Quality and Safety Risk Assessment for Tea Products (Hangzhou), Ministry of Agriculture and Rural Affairs, 9 South Meiling Road, Hangzhou, 310008, People's Republic of China.
| | - Chengyin Lu
- Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 South Meiling Road, Hangzhou, 310008, People's Republic of China.
- Key Laboratory of Tea Quality and Safety Control, Ministry of Agriculture and Rural Affairs, 9 South Meiling Road, Hangzhou, 310008, People's Republic of China.
- Laboratory of Quality and Safety Risk Assessment for Tea Products (Hangzhou), Ministry of Agriculture and Rural Affairs, 9 South Meiling Road, Hangzhou, 310008, People's Republic of China.
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17
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Rontani JF, Aubert C. Unexpected peaks in electron ionisation mass spectra of trimethylsilyl derivatives resulting from the presence of trace amounts of water and oxygen in gas chromatography/quadrupole time-of-flight systems. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33:741-743. [PMID: 30706978 DOI: 10.1002/rcm.8404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 01/25/2019] [Indexed: 06/09/2023]
Affiliation(s)
- Jean-François Rontani
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Claude Aubert
- Laboratoire de Pharmacocinétique et Toxicocinétique (EA 3286), Faculté de Pharmacie, 13385, Marseille, France
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18
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Baumeister TUH, Ueberschaar N, Pohnert G. Gas-Phase Chemistry in the GC Orbitrap Mass Spectrometer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:573-580. [PMID: 30569429 DOI: 10.1007/s13361-018-2117-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 11/23/2018] [Accepted: 11/26/2018] [Indexed: 05/06/2023]
Abstract
Gas-phase reactions of temporally stored ions play a significant role in trapped ion mass spectrometry. Especially highly labile ion species generated through electron ionization (EI) are prone to undergo gas-phase reactions after relaxation to a low vibrational state. Here, we show that in the C-Trap of the Q Exactive GC Orbitrap mass spectrometer, gaseous water reacts with radical cations of various compound classes. High-resolution accurate mass spectrometry of the resulting ions provides a key to the mechanistic understanding of the chemistry of high energetic species generated during EI. We systematically addressed water adduct formation by use of H2O and D218O in the C-Trap. Mass spectra of halogen cyanides XCN (X=Cl, Br, I) showed the formation of HXCN+ species, indicating hydrogen atomic transfer reactions. Relative ratios of HXCN+/XCN+• increased as the electronegativity of the halide increased. The common internal calibrant perfluorotributylamine forms oxygenated products from water reactive fragment ions. These can be explained by the addition of water to an initial cation followed by elimination of two HF molecules. This addition/elimination chemistry can also explain [M+2]+ and [M+3]+ ions that commonly occur in mass spectra of silylated analytes. High-resolution accurate mass spectra of trimethylsilyl (TMS) derivatives revealed these as [M-CH3•+H2O]+ and [M-CH4+H2O]•+, respectively. This study explains common fragment ions in ion trap mass spectrometry. It also opens up perspectives for the systematic mechanistic and kinetic investigation of high-energy ion reactivity. Graphical Abstract.
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Affiliation(s)
- Tim U H Baumeister
- Max Planck Fellow Group on Plankton Community Interaction, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany
| | - Nico Ueberschaar
- Institute for Inorganic and Analytical Chemistry, Mass Spectrometry Platform, Friedrich Schiller University Jena, Humboldtstr. 8, 07743, Jena, Germany
| | - Georg Pohnert
- Max Planck Fellow Group on Plankton Community Interaction, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany.
- Institute for Inorganic and Analytical Chemistry, Department of Bioorganic Analytics, Friedrich Schiller University Jena, Lessingstr. 8, 07743, Jena, Germany.
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Zheng Z, Pavlov J, Attygalle AB. Fortuitous Ion-Molecule Reaction Enables Enumeration of Metal-Hydrogen Bonds Present in Gaseous Ions. ACS OMEGA 2019; 4:3965-3972. [PMID: 31459605 PMCID: PMC6648366 DOI: 10.1021/acsomega.8b03341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/01/2019] [Indexed: 05/02/2023]
Abstract
Upon mass selection and ion activation under mass spectrometric conditions, gaseous formate adducts of many metal formates undergo decarboxylation and form product ions that bear metal-hydrogen bonds. Fortuitously, we noted that negative-ion spectra of several such formate adducts showed many peaks that could not be rationalized by the conventional fragmentation pathways attributed to the precursor ion. Subsequent experimentation proved that these enigmatic peaks are due to an ion-molecule reaction that takes place between traces of adventitious water vapor in the collision gas and the in situ formed product anions bearing metal-hydrogen bonds, generated by the fragmentation of the formate adducts. Results show that metal-hydrogen bonds of the group 2 elements are particularly susceptible to this reaction. For example, in the product-ion spectrum of [Sr(η2-O2CH)3]-, the peak at m/z 91 for SrH3 - was accompanied by three peaks at higher m/z ratios. These peaks, at m/z 107, 123, and 139, represented SrH2(OH)1 -, SrH1(OH)2 -, and Sr(OH)3 -, respectively. These satellite peaks, which were separated by 16 m/z units, were attributed to adducts formed due to the high affinity of gas-phase anions bearing metal-hydrogen bonds to water. Although undesired, these peaks are diagnostically useful to determine the number of metal-hydrogen bonds present in a precursor ion. Even though the peaks were less pronounced, analogous reactions were noted from the adducts of the group 1 elements as well. Moreover, Gibbs free energy values computed for the interaction of [H-Mg(η2-O2CH)2]- with water to form [HO-Mg(η2-OCOH)2]- and H2 indicated that this is an exergonic reaction.
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20
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Beach DG, Gabryelski W. Solution to collision induced dissociation mass spectrometry challenge. Anal Bioanal Chem 2018; 410:3927-3930. [PMID: 29926153 DOI: 10.1007/s00216-018-1044-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Daniel G Beach
- Measurement Science and Standards, National Research Council Canada, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada.
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21
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Butler M, Cabrera GM. A mass spectrometry and DFT study of pyrithione complexes with transition metals in the gas phase. JOURNAL OF MASS SPECTROMETRY : JMS 2017; 52:728-738. [PMID: 28741315 DOI: 10.1002/jms.3976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 07/05/2017] [Accepted: 07/19/2017] [Indexed: 06/07/2023]
Abstract
2-Mercaptopyridine N-oxide (pyrithione, PTOH) along with several transition metal ions forms coordination compounds displaying notable biological activities. Gas-phase complexes formed between pyrithione and manganese (II), cobalt (II), nickel (II), copper (II), and zinc (II) were investigated by infusion in the electrospray source of a quadrupole-time of flight mass spectrometer. Remarkably, positive ion mode spectra displayed the singly charged metal adduct ion [C10 H8 MN2 O2 S2 ]2+ ([M(PTO)2 ]+• or [M(DPTO)]+• ), where DPTO is dipyrithione, 2,2'-dithiobis(pyridine N-oxide), among the most abundant peaks, implying a change in the oxidation state of whether the metal ion or the ligands. In addition, doubly charged ions were recognized as metal adduct ions containing DPTO ligands, [M(DPTO)n ]2+ . Generation of [M(PTO)2 ]+• / [M(DPTO)]+• could be traced by CID of [M(DPTO)2 ]2+ , by observation of the sequential losses of a charged (PTO+ ) and a radical (PTO• ) deprotonated pyrithione ligand. The fragmentation pathways of [M(PTO)2 ]+• / [M(DPTO)]+• were compared among the different metal ions, and some common features were noticed. Density functional theory (DFT) calculations were employed to study the structures of the observed adduct ions, and especially, to decide in the adduct ion [M(PTO)2 ]+• / [M(DPTO)]+• whether the ligands are 2 deprotonated pyrithiones or a single dipyrithione as well as the oxidation state of the metal ion in the complex. Characterization of gas-phase pyrithione metal ion complexes becomes important, especially taking into account the presence of a redox-active ligand in the complexes, because redox state changes that produce new species can have a marked effect on the overall toxicological/biological response elicited by the metal system.
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Affiliation(s)
- Matias Butler
- Departamento de Química Orgánica, Ciudad Universitaria, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Pabellón II, 3° piso, C1428EHA, Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, CONICET-Universidad de Buenos Aires, Unidad de Microanálisis y Métodos Físicos aplicados a la Química Orgánica (UMYMFOR), Pabellón II, 3° piso, C1428EHA, Buenos Aires, Argentina
| | - Gabriela M Cabrera
- Departamento de Química Orgánica, Ciudad Universitaria, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Pabellón II, 3° piso, C1428EHA, Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, CONICET-Universidad de Buenos Aires, Unidad de Microanálisis y Métodos Físicos aplicados a la Química Orgánica (UMYMFOR), Pabellón II, 3° piso, C1428EHA, Buenos Aires, Argentina
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22
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Analysis of mononucleotides by tandem mass spectrometry: investigation of fragmentation pathways for phosphate- and ribose-modified nucleotide analogues. Sci Rep 2017; 7:8931. [PMID: 28827558 PMCID: PMC5567097 DOI: 10.1038/s41598-017-09416-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/24/2017] [Indexed: 12/23/2022] Open
Abstract
Synthetic nucleotide and nucleic acid analogues are useful research tools and modern therapeutics. Hence, methods for the rapid and unambiguous identification of mononucleotides derived from organic syntheses or biological materials are of broad interest. Here, we analysed over 150 mononucleotides (mostly nucleoside 5′-mono-, 5′-di-, and 5′-triphosphates) and their structurally related nucleobase-, phosphate-, and ribose-modified analogues by electrospray tandem mass spectrometry (ESI/MS/MS), identifying characteristic fragmentation ions that may be helpful in structure determination. While positive-ion mode yielded fragments derived mainly from nucleobases, negative-ion mode provided insight into the structures of phosphoryl and phosphoribosyl moieties, enabling the determination of structural features such as the number of phosphate groups and the presence of ribose or phosphate substitutions. Based on these data, we proposed fragmentation pathways that were confirmed by experiments with [18O]-isotopologues. We demonstrated the utility of ESI(−)/MS/MS in the analysis of structurally related compounds by analysing isomeric and isobaric nucleotides and applying ESI(−)/MS/MS to rapid identification of nucleotide synthesis products. We formulated general rules regarding nucleotide structure–fragmentation pattern relationships and indicating characteristic fragmentation ions for the interpretation of ESI(−)/MS/MS spectra of nucleotides and their analogues. The ESI(−)/MS/MS spectra of all nucleotides are available in an on-line database, msTide, at www.msTide-db.com.
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Lu Z, Wang Q, Wang M, Fu S, Zhang Q, Zhang Z, Zhao H, Liu Y, Huang Z, Xie Z, Yu H, Gao X. Using UHPLC Q-Trap/MS as a complementary technique to in-depth mine UPLC Q-TOF/MS data for identifying modified nucleosides in urine. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1051:108-117. [PMID: 28340480 DOI: 10.1016/j.jchromb.2017.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 02/27/2017] [Accepted: 03/01/2017] [Indexed: 12/25/2022]
Abstract
Modified nucleosides, metabolites of RNA, are potential biomarkers of cancer before the appearance of morphological abnormalities. It is of great significance to comprehensively detect and identify nucleosides in human urine for discovery of cancer biomarkers. However, the lower abundance, the greater polarity and the matrix effects make it difficult to detect urinary nucleosides. In this paper, an integrated method consisted of sample preparation followed by ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC Q-TOF/MS) detection and primary identification, then ultra-high performance liquid chromatography coupled with hybrid triple quadrupole linear ion trap mass spectrometer (UHPLC Q-Trap/MS) further identification and validation were introduced. Firstly, to enrich the nucleosides and eliminate the urine matrix effects, different sorbent materials of solid phase extraction (SPE) and the elution conditions were screened. Secondly, UPLC Q-TOF/MS was used to acquire mass data in MSE mode. The structural formulas of nucleosides in urine sample were primarily identified according to retention time, accurate mass precursor ions and fragment ions from in-house database and online database. Thirdly, the preliminary identified nucleoside structures lacking of characteristic fragment ions were verified by UHPLC Q-Trap/MS in multiple reaction monitoring trigger enhanced product ion scan (MRM-EPI) and neutral loss scan (NL). At last, phenylboronic acid (PBA)-based SPE was utilized due to its higher MS signal and weaker matrix effects under optimized extraction conditions. Fifty-five nucleosides were primarily identified by UPLC Q-TOF/MS, among which 50 nucleosides were confirmed by UHPLC Q-Trap/MS. Five nucleosides, namely 4',5'-didehydro-5'-deoxyadenosine, 4',5'-didehydro-5'-deoxyinosine, isonicotinamide riboside, peroxywybutosine and hydroxywybutosine, were found from urine for the first time. The results will expand the Human Metabolome Database (HMDB).
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Affiliation(s)
- Zhiwei Lu
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, South of Wangjing Middle Ring Road, Chaoyang District, Beijing 100102, PR China.
| | - Qing Wang
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, South of Wangjing Middle Ring Road, Chaoyang District, Beijing 100102, PR China.
| | - Meiling Wang
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, South of Wangjing Middle Ring Road, Chaoyang District, Beijing 100102, PR China.
| | - Shuang Fu
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, South of Wangjing Middle Ring Road, Chaoyang District, Beijing 100102, PR China.
| | - Qingqing Zhang
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, South of Wangjing Middle Ring Road, Chaoyang District, Beijing 100102, PR China.
| | - Zhixin Zhang
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, South of Wangjing Middle Ring Road, Chaoyang District, Beijing 100102, PR China.
| | - Huizhen Zhao
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, South of Wangjing Middle Ring Road, Chaoyang District, Beijing 100102, PR China.
| | - Yuehong Liu
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, South of Wangjing Middle Ring Road, Chaoyang District, Beijing 100102, PR China.
| | - Zhenhai Huang
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, South of Wangjing Middle Ring Road, Chaoyang District, Beijing 100102, PR China.
| | - Ziye Xie
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, South of Wangjing Middle Ring Road, Chaoyang District, Beijing 100102, PR China.
| | - Honghong Yu
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, South of Wangjing Middle Ring Road, Chaoyang District, Beijing 100102, PR China.
| | - Xiaoyan Gao
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, South of Wangjing Middle Ring Road, Chaoyang District, Beijing 100102, PR China.
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Serrano MP, Estébanez S, Vignoni M, Lorente C, Vicendo P, Oliveros E, Thomas AH. Photosensitized oxidation of 2′-deoxyguanosine 5′-monophosphate: mechanism of the competitive reactions and product characterization. NEW J CHEM 2017. [DOI: 10.1039/c7nj00739f] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We have identified five products containing oxidized guanine and another product containing an intact guanine moiety and a modified one.
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Affiliation(s)
- Mariana P. Serrano
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Departamento de Química
- Facultad de Ciencias Exactas
- Universidad Nacional de La Plata (UNLP)
- CCT La Plata-CONICET. Diagonal 113 y 64
| | - Sandra Estébanez
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Departamento de Química
- Facultad de Ciencias Exactas
- Universidad Nacional de La Plata (UNLP)
- CCT La Plata-CONICET. Diagonal 113 y 64
| | - Mariana Vignoni
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Departamento de Química
- Facultad de Ciencias Exactas
- Universidad Nacional de La Plata (UNLP)
- CCT La Plata-CONICET. Diagonal 113 y 64
| | - Carolina Lorente
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Departamento de Química
- Facultad de Ciencias Exactas
- Universidad Nacional de La Plata (UNLP)
- CCT La Plata-CONICET. Diagonal 113 y 64
| | - Patricia Vicendo
- Université Toulouse III (Paul Sabatier-Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique (IMRCP)
- UMR 5623-CNRS/UPS)
- Toulouse cédex 9
- France
| | - Esther Oliveros
- Université Toulouse III (Paul Sabatier-Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique (IMRCP)
- UMR 5623-CNRS/UPS)
- Toulouse cédex 9
- France
| | - Andrés H. Thomas
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Departamento de Química
- Facultad de Ciencias Exactas
- Universidad Nacional de La Plata (UNLP)
- CCT La Plata-CONICET. Diagonal 113 y 64
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25
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Wu RR, Chen Y, Rodgers MT. Mechanisms and energetics for N-glycosidic bond cleavage of protonated 2'-deoxyguanosine and guanosine. Phys Chem Chem Phys 2016; 18:2968-80. [PMID: 26740232 DOI: 10.1039/c5cp05738h] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Experimental and theoretical investigations suggest that hydrolysis of N-glycosidic bonds generally involves a concerted SN2 or a stepwise SN1 mechanism. While theoretical investigations have provided estimates for the intrinsic activation energies associated with N-glycosidic bond cleavage reactions, experimental measurements to validate the theoretical studies remain elusive. Here we report experimental investigations for N-glycosidic bond cleavage of the protonated guanine nucleosides, [dGuo+H](+) and [Guo+H](+), using threshold collision-induced dissociation (TCID) techniques. Two major dissociation pathways involving N-glycosidic bond cleavage, resulting in production of protonated guanine or the elimination of neutral guanine are observed in competition for both [dGuo+H](+) and [Guo+H](+). The detailed mechanistic pathways for the N-glycosidic bond cleavage reactions observed are mapped via electronic structure calculations. Excellent agreement between the measured and B3LYP calculated activation energies and reaction enthalpies for N-glycosidic bond cleavage of [dGuo+H](+) and [Guo+H](+) in the gas phase is found indicating that these dissociation pathways involve stepwise E1 mechanisms in analogy to the SN1 mechanisms that occur in the condensed phase. In contrast, MP2 is found to significantly overestimate the activation energies and slightly overestimate the reaction enthalpies. The 2'-hydroxyl substituent is found to stabilize the N-glycosidic bond such that [Guo+H](+) requires ∼25 kJ mol(-1) more than [dGuo+H](+) to activate the glycosidic bond.
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Affiliation(s)
- R R Wu
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
| | - Yu Chen
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
| | - M T Rodgers
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
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Li J, Chen Y, Diao Y, Su Y, Wang Q, Yao Z, Yi T, Jin W, Zhao D, Wang C, Liu M, Liu H. Identification of metabolites of the novel anti-tumor drug candidate MDH-7 in rat urine by liquid chromatography coupled with triple quadrupole linear ion trap mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:1001-1010. [PMID: 26969944 DOI: 10.1002/rcm.7506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 12/21/2015] [Accepted: 01/03/2016] [Indexed: 06/05/2023]
Abstract
RATIONALE Our previous preliminary pharmacokinetic study demonstrated that the novel double pyrimidine tricyclic nucleoside MDH-7 in rats had a very short half-life (<30 min) after oral administration. As a result, the in vivo metabolic profile of MDH-7 should be investigated during early stages of drug development to better select drug candidates. METHODS In this study, a rapid method was developed to identify the metabolites of MDH-7 in rat urine by means of ultra-performance liquid chromatography (UPLC) coupled with electrospray ionization mass spectrometry (ESI-MS) using a triple quadrupole linear ion trap instrument. MDH-7 and its metabolites were detected and characterized by the combined use of the multiple reaction monitoring-information-dependent acquisition-enhanced product ion (MRM-IDA-EPI) mode and the precursor scan information-dependent acquisition-enhanced product ion (PREC-IDA-EPI) mode. RESULTS Ten novel metabolites of MDH-7 were identified and characterized in rat urine by LC/ESI-MS and collision-induced dissociation tandem mass spectrometry (CID-MS/MS) analyses. M1 was identified as 5-fluoro-N(4) -[(pentyloxy)carbonyl]cytosine; M2 and M3 were formed by hydroxylation products of M1. Metabolites M4-M10 were formed by a series of degradation reactions such as: deacetylation, hydroxylation, loss of the defluorocytosine base, oxidative-deamination, loss of the defluorouracil base, N-dealkylation and amide hydrolysis. CONCLUSIONS Based on the profiles of the metabolites, possible metabolic pathways of MDH-7 in rats were proposed for the first time. This study provides new and available information on the metabolism of MDH-7 which is very useful to further understand its in vivo metabolic fate. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Juan Li
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, China
- Collaborative Innovation Center of New Drug Research and Safety Evaluation, Henan Province, Zhengzhou, 450001, China
| | - Yu Chen
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, China
| | - Yanyan Diao
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, China
| | - Yingqian Su
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, China
| | - Qingli Wang
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, China
| | - Zhicun Yao
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, China
| | - Tianxiang Yi
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, China
| | - Wenting Jin
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, China
| | - Dan Zhao
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, China
| | - Caihong Wang
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, China
| | - Mengru Liu
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, China
| | - Hongmin Liu
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou, 450001, China
- Collaborative Innovation Center of New Drug Research and Safety Evaluation, Henan Province, Zhengzhou, 450001, China
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Ion-molecule adduct formation in tandem mass spectrometry. Anal Bioanal Chem 2015; 408:1269-77. [PMID: 26700446 DOI: 10.1007/s00216-015-9237-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 11/24/2015] [Accepted: 11/30/2015] [Indexed: 10/22/2022]
Abstract
Nowadays most LC-MS methods rely on tandem mass spectrometry not only for quantitation and confirmation of compounds by multiple reaction monitoring (MRM), but also for the identification of unknowns from their product ion spectra. However, gas-phase reactions between charged and neutral species inside the mass analyzer can occur, yielding product ions at m/z values higher than that of the precursor ion, or at m/z values difficult to explain by logical losses, which complicate mass spectral interpretation. In this work, the formation of adduct ions in the mass analyzer was studied using several mass spectrometers with different mass analyzers (ion trap, triple quadrupole, and quadrupole-Orbitrap). Heterocyclic amines (AαC, MeAαC, Trp-P-1, and Trp-P-2), photo-initiators (BP and THBP), and pharmaceuticals (phenacetin and levamisole) were selected as model compounds and infused in LCQ Classic, TSQ Quantum Ultra AM, and Q-Exactive Orbitrap (ThermoFisher Scientific) mass spectrometers using electrospray as ionization method. The generation of ion-molecule adducts depended on the compound and also on the instrument employed. Adducts with neutral organic solvents (methanol and acetonitrile) were only observed in the ion trap instrument (LCQ Classic), because of the ionization source on-axis configuration and the lack of gas-phase barriers, which allowed inertial entrance of the neutrals into the analyzer. Adduct formation (only with water) in the triple quadrupole instruments was less abundant than in the ion trap and quadrupole-Orbitrap mass spectrometers, because of the lower residence time of the reactive product ions in the mass analyzer. The moisture level of the CID and/or damper gas had a great effect in beam-like mass analyzers such as triple quadrupole, but not in trap-like mass analyzers, probably because of the long residence time that allowed adduct formation even with very low concentrations of water inside the mass spectrometer.
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Chen J, Green KB, Nichols KK. Characterization of Wax Esters by Electrospray Ionization Tandem Mass Spectrometry: Double Bond Effect and Unusual Product Ions. Lipids 2015; 50:821-36. [PMID: 26178197 DOI: 10.1007/s11745-015-4044-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 06/22/2015] [Indexed: 11/26/2022]
Abstract
A series of different types of wax esters (represented by RCOOR') were systematically studied by using electrospray ionization (ESI) collision-induced dissociation tandem mass spectrometry (MS/MS) along with pseudo MS(3) (in-source dissociation combined with MS/MS) on a quadrupole time-of-flight (Q-TOF) mass spectrometer. The tandem mass spectra patterns resulting from dissociation of ammonium/proton adducts of these wax esters were influenced by the wax ester type and the collision energy applied. The product ions [RCOOH2](+), [RCO](+) and [RCO-H2O](+) that have been reported previously were detected; however, different primary product ions were demonstrated for the three wax ester types including: (1) [RCOOH2](+) for saturated wax esters, (2) [RCOOH2](+), [RCO](+) and [RCO-H2O](+) for unsaturated wax esters containing only one double bond in the fatty acid moiety or with one additional double bond in the fatty alcohol moiety, and (3) [RCOOH2](+) and [RCO](+) for unsaturated wax esters containing a double bond in the fatty alcohol moiety alone. Other fragments included [R'](+) and several series of product ions for all types of wax esters. Interestingly, unusual product ions were detected, such as neutral molecule (including water, methanol and ammonia) adducts of [RCOOH2](+) ions for all types of wax esters and [R'-2H](+) ions for unsaturated fatty acyl-containing wax esters. The patterns of tandem mass spectra for different types of wax esters will inform future identification and quantification approaches of wax esters in biological samples as supported by a preliminary study of quantification of isomeric wax esters in human meibomian gland secretions.
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Affiliation(s)
- Jianzhong Chen
- Applied Biotechnology Branch, Air Force Research Laboratory, Dayton, OH, 45433, USA,
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29
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Liang Y, Neta P, Simón-Manso Y, Stein SE. Reaction of arylium ions with the collision gas N2 in electrospray ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:629-636. [PMID: 26212280 DOI: 10.1002/rcm.7147] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/08/2015] [Accepted: 01/09/2015] [Indexed: 05/18/2023]
Abstract
RATIONALE The tandem mass spectra of many compounds contained peaks which could not have arisen from the precursor ion. Such peaks were found to be due to reaction of arylium ions with N2 in the collision cell. Therefore, this reaction was studied in detail with representative compounds. METHODS Various classes of compounds were dissolved in acetonitrile/water/formic acid and studied by electrospray ionization mass spectrometry to record their MS(2) and pseudo-MS(3) spectra in a QqQ mass spectrometer and their accurate m/z values in an Orbitrap Elite instrument. Arylium ions were found to react with N2 in the collision cell. The reaction was confirmed by pseudo-MS(3) studies, by comparison with authentic diazonium ions, and by the pressure dependence of the product ion survival yield. RESULTS Reactions of arylium ions with N2 were observed with p-toluenesulfonic acid, o-toluenesulfonamide, phenylphosphonic acid, phenol, aniline, aminonaphthalenes, benzoic acid, benzophenone, and other compounds. By using a QqQ mass spectrometer, we observed that the protonated compounds produce arylium ions, which then react with N2 to form diazonium ions. The diazonium ion was produced with N2 but not with Ar in the collision cell, and its abundance increased with increasing N2 pressure. CONCLUSIONS Arylium ions generated from a wide variety of compounds in electrospray ionization tandem mass spectrometry may react with N2 to form diazonium ions. The abundance of the diazonium ions is affected by collision energy and N2 pressure. This reaction should be considered when annotating peaks in MS/MS libraries. Published in 2015. This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Yuxue Liang
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Pedatsur Neta
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Yamil Simón-Manso
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Stephen E Stein
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
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30
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Butler M, Cabrera GM. A mass spectrometry-based method for differentiation of positional isomers of monosubstituted pyrazine N-oxides using metal ion complexes. JOURNAL OF MASS SPECTROMETRY : JMS 2015; 50:136-144. [PMID: 25601685 DOI: 10.1002/jms.3506] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 09/05/2014] [Accepted: 09/10/2014] [Indexed: 06/04/2023]
Abstract
A series of 11 pairs of substituted pyrazine N-oxides, differing in the substituent position, were examined using electrospray ionization mass spectrometry (ESI-MS) in order to use spectra to assess the differentiation of positional isomers. For each compound, mass spectra were recorded with three different metal cations, namely calcium (II), copper (II) and aluminum (III), with characterization of the observed peaks. Differentiation between regioisomeric N-oxides has been achieved by comparison of the identity and relative intensities of the peaks originating from the adduct ions formed with the metal ions. Principal component analysis (PCA) has been employed to assist in the interpretation of the results obtained with each metal ion, exploring possible trends according to the nature and position of the substituent in the pyrazine N-oxide.
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Affiliation(s)
- Matías Butler
- Departamento de Química Orgánica, UMyMFOR-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 3° piso, C1428EHA, Buenos Aires, Argentina
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31
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Neta P, Farahani M, Simón-Manso Y, Liang Y, Yang X, Stein SE. Unexpected peaks in tandem mass spectra due to reaction of product ions with residual water in mass spectrometer collision cells. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014; 28:2645-60. [PMID: 25366411 DOI: 10.1002/rcm.7055] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 09/12/2014] [Accepted: 09/15/2014] [Indexed: 05/18/2023]
Abstract
RATIONALE Certain product ions in electrospray ionization tandem mass spectrometry are found to react with residual water in the collision cell. This reaction often leads to the formation of ions that cannot be formed directly from the precursor ions, and this complicates the mass spectra and may distort MRM (multiple reaction monitoring) results. METHODS Various drugs, pesticides, metabolites, and other compounds were dissolved in acetonitrile/water/formic acid and studied by electrospray ionization mass spectrometry to record their MS(2) and MS(n) spectra in several mass spectrometers (QqQ, QTOF, IT, and Orbitrap HCD). Certain product ions were found to react with residual water in collision cells. The reaction was confirmed by MS(n) studies and the rate of reaction was determined in the IT instrument using zero collision energy and variable activation times. RESULTS Examples of product ions reacting with water include phenyl and certain substituted phenyl cations, benzoyl-type cations formed from protonated folic acid and similar compounds by loss of the glutamate moiety, product ions formed from protonated cyclic siloxanes by loss of methane, product ions formed from organic phosphates, and certain negative ions. The reactions of product ions with residual water varied greatly in their rate constant and in the extent of reaction (due to isomerization). CONCLUSIONS Various types of product ions react with residual water in mass spectrometer collision cells. As a result, tandem mass spectra may contain unexplained peaks and MRM results may be distorted by the occurrence of such reactions. These often unavoidable reactions must be taken into account when annotating peaks in tandem mass spectra and when interpreting MRM results. Published in 2014. This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Pedatsur Neta
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
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32
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Jariwala FB, Hibbs JA, Weisbecker CS, Ressler J, Khade RL, Zhang Y, Attygalle AB. A distonic radical-ion for detection of traces of adventitious molecular oxygen (O2) in collision gases used in tandem mass spectrometers. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2014; 25:1670-3. [PMID: 25001381 DOI: 10.1007/s13361-014-0945-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 05/26/2014] [Accepted: 05/27/2014] [Indexed: 05/18/2023]
Abstract
We describe a diagnostic ion that enables rapid semiquantitative evaluation of the degree of oxygen contamination in the collision gases used in tandem mass spectrometers. Upon collision-induced dissociation (CID), the m/z 359 positive ion generated from the analgesic etoricoxib undergoes a facile loss of a methyl sulfone radical [(•)SO(2)(CH(3)); 79-Da] to produce a distonic radical cation of m/z 280. The product-ion spectrum of this m/z 280 ion, recorded under low-energy activation on tandem-in-space QqQ or QqTof mass spectrometers using nitrogen from a generator as the collision gas, or tandem-in-time ion-trap (LCQ, LTQ) mass spectrometers using purified helium as the buffer gas, showed two unexpected peaks at m/z 312 and 295. This enigmatic m/z 312 ion, which bears a mass-to-charge ratio higher than that of the precursor ion, represented an addition of molecular oxygen (O(2)) to the precursor ion. The exceptional affinity of the m/z 280 radical cation towards oxygen was deployed to develop a method to determine the oxygen content in collision gases.
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Affiliation(s)
- Freneil B Jariwala
- Center for Mass Spectrometry, Department of Chemistry, Chemical Biology and Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ, 07030, USA
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33
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Dudley E, Bond L. Mass spectrometry analysis of nucleosides and nucleotides. MASS SPECTROMETRY REVIEWS 2014; 33:302-31. [PMID: 24285362 DOI: 10.1002/mas.21388] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 05/03/2013] [Accepted: 05/03/2013] [Indexed: 05/12/2023]
Abstract
Mass spectrometry has been widely utilised in the study of nucleobases, nucleosides and nucleotides as components of nucleic acids and as bioactive metabolites in their own right. In this review, the application of mass spectrometry to such analysis is overviewed in relation to various aspects regarding the analytical mass spectrometric and chromatographic techniques applied and also the various applications of such analysis.
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Affiliation(s)
- Ed Dudley
- Institute of Mass Spectrometry, College of Medicine, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
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34
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Sangaraju D, Villalta PW, Wickramaratne S, Swenberg J, Tretyakova N. NanoLC/ESI+ HRMS3 quantitation of DNA adducts induced by 1,3-butadiene. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2014; 25:1124-35. [PMID: 24867429 PMCID: PMC5076477 DOI: 10.1007/s13361-014-0916-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 04/11/2014] [Accepted: 04/14/2014] [Indexed: 06/03/2023]
Abstract
Human exposure to 1,3-butadiene (BD) present in automobile exhaust, cigarette smoke, and forest fires is of great concern because of its potent carcinogenicity. The adverse health effects of BD are mediated by its epoxide metabolites such as 3,4-epoxy-1-butene (EB), which covalently modify genomic DNA to form promutagenic nucleobase adducts. Because of their direct role in cancer, BD-DNA adducts can be used as mechanism-based biomarkers of BD exposure. In the present work, a mass spectrometry-based methodology was developed for accurate, sensitive, and precise quantification of EB-induced N-7-(1-hydroxy-3-buten-2-yl) guanine (EB-GII) DNA adducts in vivo. In our approach, EB-GII adducts are selectively released from DNA backbone by neutral thermal hydrolysis, followed by ultrafiltration, offline HPLC purification, and isotope dilution nanoLC/ESI(+)-HRMS(3) analysis on an Orbitrap Velos mass spectrometer. Following method validation, EB-GII lesions were quantified in human fibrosarcoma (HT1080) cells treated with micromolar concentrations of EB and in liver tissues of rats exposed to sub-ppm concentrations of BD (0.5-1.5 ppm). EB-GII concentrations increased linearly from 1.15 ± 0.23 to 10.11 ± 0.45 adducts per 10(8) nucleotides in HT1080 cells treated with 0.5-10 μM EB. EB-GII concentrations in DNA of laboratory rats exposed to 0.5, 1.0, and 1.5 ppm BD were 0.17 ± 0.05, 0.33 ± 0.08, and 0.50 ± 0.04 adducts per 10(8) nucleotides, respectively [corrected]. We also used the new method to determine the in vivo half-life of EB-GII adducts in rat liver DNA (2.20 ± 0.12 d) and to detect EB-GII in human blood DNA. To our knowledge, this is the first application of nanoLC/ESI(+)-HRMS(3) Orbitrap methodology to quantitative analysis of DNA adducts in vivo.
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Affiliation(s)
- Dewakar Sangaraju
- Department of Medicinal Chemistry and the Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455
| | - Peter W. Villalta
- Department of Medicinal Chemistry and the Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455
| | - Susith Wickramaratne
- Department of Medicinal Chemistry and the Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455
| | - James Swenberg
- Department of Environmental Sciences and Engineering, The University of North Carolina, Chapel Hill, NC, USA
| | - Natalia Tretyakova
- Department of Medicinal Chemistry and the Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455
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35
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Butler M, Mañez PA, Cabrera GM, Maître P. Gas phase structure and reactivity of doubly charged microhydrated calcium(II)-catechol complexes probed by infrared spectroscopy. J Phys Chem A 2014; 118:4942-54. [PMID: 24963704 DOI: 10.1021/jp503789j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Doubly charged microhydrated adducts formed from catechol and calcium(II) were produced in the gas phase using electrospray ionization (ESI) appearing as the most important ions in the mass spectra recorded. The gas phase structures of [Ca(catechol)2(H2O)](2+) and [Ca(catechol)2(H2O)2](2+) have been assayed by IR multiphoton dissociation (IRMPD) spectroscopy, recording their vibrational spectra in the 3450-3750 cm(-1) range (OH stretching region) and in the 900-1700 cm(-1) fingerprint spectral region. The agreement between experimental and calculated IR spectra of the selected cluster ions confirmed the suitability of the proposed geometries. In addition, quantum chemical calculations at the B3LYP/6-311+G(d,p) level of theory were performed for [Ca(catechol)2(H2O)](2+) to gain insight into the major routes of dissociation. The results suggest that loss of the water molecule is the lowest energy fragmentation channel followed by charge separation products and neutral loss of one catechol molecule, in agreement with the product ions observed upon collision-induced dissociation (CID).
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Affiliation(s)
- Matias Butler
- Departamento de Química Orgánica, UMyMFOR-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria , Pabellón II, 3° piso, C1428EHA, Buenos Aires, Argentina
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36
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Affiliation(s)
- Natalia Tretyakova
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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37
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Wu YQ, Zhang NW, Li F, Jiang KZ. Deviant mass shift of hydrated product ions from sodiated beta-anilinodidrochalcones using an ion-trap mass spectrometer. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2013; 19:351-359. [PMID: 24800419 DOI: 10.1255/ejms.1244] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The fragmentation reactions of sodiated beta-anilinodidrochalcones have been investigated by electrospray ionization multi-stage mass spectrometry (ESI-MS(n)). The fragment ion of sodiated N-benzylidenebenzenamine (P1) easily undergoes ion-molecule reactions with the residual ESI solvent molecules (H2O and CH3OH) in the vacuum system, as verified by MS3 and accurate MS analysis. The formed hydrated ions appear as an unusual leading peak in the profile spectrum, which results in a deviant decreasing mass shift of almost 1 Da. Density functional theory calculations indicate that P1 easily associates with H2O without any energy barrier. Thus, the hydrated P1 exists partially as a loose system of P1 and H2O, which provides a reasonable explanation for the decreasing mass shift of the solvated P1. The above results are important in obtaining structural information from MS(n) spectra and preventing erroneous data interpretation for the analogous adducts.
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38
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Fryčák P, Jirkovský J, Ranc V, Bednář P, Havlíček V, Lemr K. Secondary processes in atmospheric pressure chemical ionization-ion trap mass spectrometry: a case study of orotic acid. JOURNAL OF MASS SPECTROMETRY : JMS 2012; 47:720-726. [PMID: 22707164 DOI: 10.1002/jms.3006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Atmospheric pressure chemical ionization is known for producing unusual artifacts of the ionization process in some cases. In this work, processes occuring in atmospheric pressure chemical ionization/MS of orotic acid that afforded ions accompanying protonated and deprotonated orotic acid molecules in the spectra were studied. Two processes ran in parallel in the ion source: decarboxylation of neutral orotic acid and collision-induced dissociation of its protonated or deprotonated form. A procedure discerning pre-ionization decomposition and post-ionization dissociation by manipulating ion source parameters was proposed. Experiments with isotopically labeled solvents confirmed ion-molecule reactions of the product of collision-induced dissociation of protonated orotic acid with solvent molecules in the ion source and even under vacuum in the ion trap.
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Affiliation(s)
- Petr Fryčák
- Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University in Olomouc, Olomouc, Czech Republic
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39
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Purna Chander C, Raju G, Mathai G, Srinivas R, Gaikwad HK, Bantu R, Nagarapu L. Electrospray ionization tandem mass spectrometry of 3-phenyl-N-(3-(4-phenylpiperazin-1-yl)propyl)-1H-pyrazole-5-carboxamide derivatives: unusual fragmentation involving loss of 11 u. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2012; 26:207-214. [PMID: 22173810 DOI: 10.1002/rcm.5318] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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40
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Plattner S, Erb R, Pitterl F, Brouwer HJ, Oberacher H. Formation and characterization of covalent guanosine adducts with electrochemistry-liquid chromatography-mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 883-884:198-204. [PMID: 22000962 PMCID: PMC3284773 DOI: 10.1016/j.jchromb.2011.09.050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 09/12/2011] [Accepted: 09/27/2011] [Indexed: 01/14/2023]
Abstract
Chemicals can interact with the genetic material giving rise to the formation of covalent adducts. These alterations can lead to adverse consequences, including cancer, reproductive impairment, development anomalies, or genetic diseases. In search for an assay allowing identification of hazardous compounds that might form covalent adducts with nucleic acids, electrochemistry (EC)/liquid chromatography (LC)/mass spectrometry (MS) is presented. EC/LC/MS is a purely instrumental approach. EC is used for oxidative activation, LC for the fractionation of the reaction mixture, and MS for the detection and characterization of the reaction products. To test the system capabilities, we investigated the formation of covalent adducts produced by guanosine and acetaminophen (APAP). Electrochemical activation of mixtures of guanosine and APAP gave rise to the formation of four isomers of (guanosine + APAP-2H). Mass voltammograms as well as dose–response-curves were used to obtain insights in the mechanism of adduct formation. These experiments revealed that a mechanism involving radical intermediates is favored. The initial step of adduct formation is the conversion of both APAP and guanosine into radicals via one-electron–one-proton reactions. Among different competing reaction pathways, the generated radical intermediates undergo intermolecular reactions to form covalent adducts between guanosine and APAP.
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Affiliation(s)
- Sabine Plattner
- Institute of Legal Medicine, Innsbruck Medical University, Innsbruck, Austria
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41
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Sagoo S, Beach DG, Manderville RA, Gabryelski W. Tautomerization in gas-phase ion chemistry of isomeric C-8 deoxyguanosine adducts from phenol-induced DNA damage. JOURNAL OF MASS SPECTROMETRY : JMS 2011; 46:41-9. [PMID: 21184435 DOI: 10.1002/jms.1869] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Collision-induced dissociation (CID) of 8-(4''-hydroxyphenyl)-2'-deoxyguanosine and 8-(2''-hydroxyphenyl)-2'-deoxyguanosine was investigated using sequential tandem mass spectrometry. These adducts represent biomarkers of DNA damage linked to phenolic radicals and were investigated to gain insight into the effects of chemical structure of a C-8 modification on fragmentation pathways of modified 2'-deoxyguanosine (dG). CID in MS(2) of the deprotonated molecules of both the isomers generated the same product ion having the same m/z values. CID in MS(3) of the product ion at m/z 242 and CID in MS(4) experiments carried out on the selected product ions at m/z 225 and m/z 218 afford distinct fragmentation patterns. The conformational properties of isomeric product ions from CID showed that the ortho-isomers possess the unique ability to tautomerize through an intramolecular proton transfer between the phenolic OH group and the imine nitrogen (N7). Tautomerization of ortho-isomers to their keto-tautomers led to differences in their system of conjugated double bonds compared with either their enol-tautomer or the para-isomer. The charge redistribution through the N-7 site on the imidazole ring is a critical step in guanosine adduct fragmentation which is disrupted by the formation of the keto-tautomer. For this reason, different reaction pathways are observed for 8-(4''-hydroxyphenyl)-2'-deoxyguanosine and 8-(2''-hydroxyphenyl)-2'-deoxyguanosine. We present herein the dissociation and the gas-phase ion-molecule reactions for highly conjugated ions involved in the CID ion chemistry of the investigated adducts. These will be useful for those using tandem mass spectrometry for structural elucidation of C-8 modified dG adducts. This study demonstrates that the modification at the C-8 site of dG has the potential to significantly alter the reactivity of adducts. We also show the ability of tandem mass spectrometry to completely differentiate between the isomeric dG adducts investigated.
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Affiliation(s)
- Sandeep Sagoo
- Department of Chemistry, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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42
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Chan CC, Axe FU, Bolgar M, Attygalle AB. Reactivity of gaseous sodiated ions derived from benzene dicarboxylate salts toward residual water in the collision gas. JOURNAL OF MASS SPECTROMETRY : JMS 2010; 45:1130-1138. [PMID: 20853346 DOI: 10.1002/jms.1792] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The sodium adduct of disodium salts of benzene dicarboxylic acids (m/z 233), when subjected to collision-induced dissociation (CID), undergoes a facile loss of CO(2) to produce an ion of m/z 189, which retains all the three sodium atoms of the precursor. The CID spectrum of this unusual m/z 189 ion shows significant peaks at m/z 167, 63 and 85. The enigmatic m/z 167 ion, which appeared to represent a loss of a 22-Da neutral fragment from the precursor ion is in fact a fragment produced by the interaction of the m/z 189 ion with traces of water present in the collision gas. The change of the m/z 167 peak to 168, when D(2)O vapor was introduced to the collision gas of a Q-ToF instrument, proved that such an intervention of water could occur even in collision cells of tandem-in-space mass spectrometers. The m/z 189 ion has such high affinity for water; it forms an ion/molecule complex even during the brief residence time of ions in collision cells of triple quadrupole instruments. The complex formed in this way then eliminates elements of NaOH to produce the ion observed at m/z 167. In an ion trap, the relative intensity of the m/z 167 peak increases with longer activation time even at the lowest possible collision energy setting. Similarly, the m/z 145 ion (which represents the sodium adduct of phenelenedisodium, formed by two consecutive losses of CO(2) from the m/z 233 ion of meta- and para-isomers) interacts with water to produce a fragment ion at m/z 123 for the sodium adduct of phenylsodium. Other uncommon ions that originate also from water/ion interactions are observed at m/z 85 and 63 for [Na(3)O](+) and [Na(2)OH](+), respectively. Tandem mass spectrometric experiments conducted with appropriately deuterium-labeled compounds confirmed that the proton required for the formation of the [Na(2)OH](+) ion originates from traces of water present in the collision gas and not from the ring protons of the aromatic moiety.
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Affiliation(s)
- Chang-Ching Chan
- Center for Mass Spectrometry, Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA
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Cheng P, Li Y, Li S, Zhang M, Zhou Z. Collision-induced dissociation (CID) of guanine radical cation in the gas phase: an experimental and computational study. Phys Chem Chem Phys 2010; 12:4667-77. [DOI: 10.1039/b919513k] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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44
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Dudley E, Yousef M, Wang Y, Griffiths WJ. Targeted metabolomics and mass spectrometry. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2010; 80:45-83. [PMID: 21109217 DOI: 10.1016/b978-0-12-381264-3.00002-3] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
While a great emphasis has been placed on global metabolomic analysis in recent years, the application of metabolomic style analyses to specific subsets of compounds (targeted metabolomics) also has merits in addressing biological questions in a more hypothesis-driven manner. These analyses are designed to selectively extract information regarding a group of related metabolites from the complex mixture of biomolecules present in most metabolomic samples. Furthermore, targeted metabolomics can also be applied to metabolism within macromolecules, hence furthering the systems biology impact of the analysis. This chapter describes the difference between the global metabolomics approach and the undertaking of metabolomics in a targeted manner and describes the application of this type of analysis in a number of biologically and medically relevant fields.
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Affiliation(s)
- E Dudley
- Institute of Mass Spectrometry, Swansea University, United Kingdom
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Lee SK, Kim HJ, Jin C, Lee J. Formation of the unusual [M+H-11 Da]+ ion peak in the collision-induced dissociation mass spectrum of [M+H]+ ion of hydrochlorothiazide. JOURNAL OF MASS SPECTROMETRY : JMS 2009; 44:1538-1541. [PMID: 19753616 DOI: 10.1002/jms.1640] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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46
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Cao X, Yu Y, Ye X, Mo W. Solvation in gas-phase reactions of sulfonic group containing ionic liquids in electrospray ionization quadrupole ion trap mass spectrometry. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2009; 15:409-413. [PMID: 19395776 DOI: 10.1255/ejms.985] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In electrospray ionization (ESI) quadrupole ion trap mass spectrometry, certain fragment ions generated in the ion trap from a series of sulfonic group containing ionic liquids (ILs) are found to undergo ion-molecule reactions with ESI solvent molecules (water, acetonitrile and methanol) to form adduct species. These unexpected solvated fragment ions severely complicate the interpretation of mass spectrometric data. Multi-stage fragmentation mass spectra were used to ascertain the chemical structures of these adduct species. It is important that solvation must be taken into account in order to prevent erroneous data interpretation for sulfonic group containing ILs.
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Affiliation(s)
- Xiaoji Cao
- Research Center of Analysis and Measurement, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China.
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De Winter J, Goffin AL, Coulembier O, Dubois P, Flammang R, Gerbaux P. Metastable processes investigated on an orthogonal-axis time-of-flight instrument: mass-scale calibration and application. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2009; 15:431-437. [PMID: 19395778 DOI: 10.1255/ejms.973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In this letter, the authors would like to present a rapid method for mass-scale calibration of metastable dissociation in an orthogonalaxis time-of-flight instrument. The calibrating ion is a protonated polyhedral oligomeric silsesquioxane (POSS) generated in electrospray ionization. In addition, dissociation mechanisms for protonated POSS are proposed. Finally, the interest of the method is illustrated in the context of a collision-induced dissociation investigation of sodium-cationized polylactide.
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Bullinger D, Fux R, Nicholson G, Plontke S, Belka C, Laufer S, Gleiter CH, Kammerer B. Identification of urinary modified nucleosides and ribosylated metabolites in humans via combined ESI-FTICR MS and ESI-IT MS analysis. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2008; 19:1500-1513. [PMID: 18657436 DOI: 10.1016/j.jasms.2008.06.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 06/19/2008] [Accepted: 06/20/2008] [Indexed: 05/26/2023]
Abstract
The physiological response of the human body to several diseases can be reflected by the metabolite pattern in biological fluids. Cancer, like other diseases accompanied by metabolic disorders, causes characteristic effects on cell turnover rate, activity of modifying enzymes, and RNA/DNA modifications. This results in an altered excretion of modified nucleosides and biochemically related compounds. In the course of our metabolic profiling project, we screened 24-h urine of patients suffering from lung, rectal, or head and neck cancer for previously unknown ribosylated metabolites. Therefore, we developed a sample preparation procedure based on boronate affinity chromatography followed by additional prepurification with preparative TLC. The isolated metabolites were analyzed by ion trap mass spectrometry (IT MS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS). IT MS was applied for LC-auto MS(3) screening runs and MS(n(n=4-6)) syringe pump infusion experiments, yielding characteristic fragmentation patterns. FTICR MS measurements enabled the calculation of corresponding molecular formulae based on accurate mass determination (mass accuracy: 1-5 ppm for external and sub-ppm values for internal calibration). We were able to identify 22 metabolites deriving from cellular RNA metabolism and related metabolic pathways like histidine metabolism, purine biosynthesis, methionine/polyamine cycle, and nicotinate/nicotinamide metabolism. The compounds 1-ribosyl-3-hydroxypyridinium, 1-ribosyl-pyridinium, and 3-ribosyl-1-methyl-l-histidinium as well as a series of ribosylated histamines, conjugated to carboxylic acids at the N(omega)-position were found as novel urinary constituents. The occurrence of the modified nucleosides 2-methylthio-N(6)-(cis-hydroxyisopentenyl)-adenosine, 5-methoxycarbonylmethyl-2-thiouridine, N(6)-methyl-N(6)-threonylcarbamoyladenosine, and 2-methylthio-N(6)-threonylcarbamoyladenosine in human urine is verified for the first time.
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Affiliation(s)
- Dino Bullinger
- Department of Clinical Pharmacology, Institute of Pharmacology and Toxicology, University Hospital Tübingen, Tübingen, Germany
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Park IH, Pritchard DG, Cartee R, Brandao A, Brandileone MCC, Nahm MH. Discovery of a new capsular serotype (6C) within serogroup 6 of Streptococcus pneumoniae. J Clin Microbiol 2007; 45:1225-33. [PMID: 17267625 PMCID: PMC1865839 DOI: 10.1128/jcm.02199-06] [Citation(s) in RCA: 336] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using two monoclonal antibodies, we found subtypes among pneumococcal isolates that are typed as serotype 6A by the quellung reaction. The prevalent subtype bound to both monoclonal antibodies and was labeled here 6Aalpha, whereas the minor subtype bound to only one monoclonal antibody and was labeled 6Abeta. To determine the biochemical nature of the two serologically defined subtypes, we purified capsular polysaccharides (PSs) from the two subtypes and examined their chemical structures with gas-liquid chromatography and mass spectrometry. The study results for 6Aalpha PS are consistent with the previously published structure of 6A PS, which is -->2) galactose (1-->3) glucose (1-->3) rhamnose (1-->3) ribitol (5-->phosphate. In contrast, the 6Abeta PS study results show that its repeating unit is -->2) glucose 1 (1-->3) glucose 2 (1-->3) rhamnose (1-->3) ribitol (5-->phosphate. We propose to continue referring to 6Aalpha as serotype 6A but to refer to 6Abeta as serotype 6C. Serotype 6C would thus represent the 91st pneumococcal serotype, with 90 pneumococcal serotypes having previously been recognized. This study also demonstrates that a new serotype may exist within an established and well-characterized serogroup or serotype.
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Affiliation(s)
- In Ho Park
- Department of Pathology, University of Alabama at Birmingham, 845 19th Street South (BBRB 614), Birmingham, AL 35294, USA.
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Rubino FM, Pitton M, Brambilla G, Colombi A. Electrospray ionization and triple quadrupole tandem mass spectrometry study of some biologically relevant homo- and heterodimeric cadmium thiolate conjugates. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2006; 17:1443-1455. [PMID: 16872835 DOI: 10.1016/j.jasms.2006.06.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 06/21/2006] [Accepted: 06/21/2006] [Indexed: 05/11/2023]
Abstract
A series of 19 compounds of general formula R1S-Cd-SR2, R1, and R2, being some biologically relevant thiol amino acids and peptides, were prepared by direct reaction of cadmium(II) ions and thiols in water at millimolar concentration. The obtained products were characterized by electrospray ionization and triple quadrupole tandem mass spectrometry. The source spectra of stoichiometric 1:2 Cd-thiol systems containing either an individual thiol or equimolar mixtures of two different thiols featured several Cd-containing signals, although at much lesser intensity than in the previously reported experiments with mercury(II) (J. Am. Soc. Mass Spectrom. 2004, 15, 288-300). Also, the relative intensity of the homo- and heterodimeric thiolates were significantly different from the theoretically expected 1:2:1 ratio, thus pointing at some degree of discrimination between the different thiols. In particular, homo-cysteine showed much less reactivity than cysteine, and penicillamine and cysteine methyl ester much less than the free amino acid. The fragment spectra show structure-specific ions for the different ligands bound to the metal ion and allow a stand-alone determination of the connectivity also of isomeric pairs. The fragmentation pathways are similar to those observed for the corresponding mercury(II) analogues, with the addition of further intense and specific fragments, one formally carrying a Cd-bound OH ligand and one connected as a five-membered oxazolone carrying a cadmium-bis-thiolate side chain, both formed with a high intensity. Energy-resolved fragmentation data show that metal-free ions can be generated from cysteine but not from glutathione conjugates and point to the possibility of unveiling differences in the biochemical behavior of the conjugates of different heavy metals through the detailed study of their mass spectrometric fragmentation.
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Affiliation(s)
- Federico Maria Rubino
- Laboratory for Analytical Toxicology and Metabolomics, Department of Occupational Medicine, Università degli Studi di Milano at Ospedale San Paolo, v. A di Rudinì 8, I-20142, Milano, Italy.
| | - Marco Pitton
- Laboratory for Analytical Toxicology and Metabolomics, Department of Occupational Medicine, Università degli Studi di Milano at Ospedale San Paolo, v. A di Rudinì 8, I-20142, Milano, Italy
| | - Gabri Brambilla
- Laboratory for Analytical Toxicology and Metabolomics, Department of Occupational Medicine, Università degli Studi di Milano at Ospedale San Paolo, v. A di Rudinì 8, I-20142, Milano, Italy
| | - Antonio Colombi
- Laboratory for Analytical Toxicology and Metabolomics, Department of Occupational Medicine, Università degli Studi di Milano at Ospedale San Paolo, v. A di Rudinì 8, I-20142, Milano, Italy
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