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Lee J, Tantillo DJ, Wang LP, Fiehn O. Impact of Protonation Sites on Collision-Induced Dissociation-MS/MS Using CIDMD Quantum Chemistry Modeling. J Chem Inf Model 2024. [PMID: 39329341 DOI: 10.1021/acs.jcim.4c00761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2024]
Abstract
Protonation is the most frequent adduct found in positive electrospray ionization collision-induced mass spectra (CID-MS/MS). In a parallel report Lee, J. J. Chem. Inf. Model. 2024, 10.1021/acs.jcim.4c00760, we developed a quantum chemistry framework to predict mass spectra by collision-induced dissociation molecular dynamics (CIDMD). As different protonation sites affect fragmentation pathways of a given molecule, the accuracy of predicting tandem mass spectra by CIDMD ultimately depends on the choice of its protomers. To investigate the impact of molecular protonation sites on MS/MS spectra, we compared CIDMD-predicted spectra to all available experimental MS/MS spectra by similarity matching. We probed 10 molecules with a total of 43 protomers, the largest study to date, including organic acids (sorbic acid, citramalic acid, itaconic acid, mesaconic acid, citraconic acid, and taurine) as well as aromatic amines including uracil, aniline, bufotenine, and psilocin. We demonstrated how different protomers can converge different fragmentation pathways to the same fragment ions but also may explain the presence of different fragment ions in experimental MS/MS spectra. For the first time, we used in silico MS/MS predictions to test the impact of solvents on proton affinities, comparing the gas phase and a mixture of acetonitrile/water (1:1). We also extended applications of in silico MS/MS predictions to investigate the impact of protonation sites on the energy barriers of isomerization between protomers via proton transfer. Despite our initial hypothesis that the thermodynamically most stable protomer should give the best match to the experiment, we found only weak inverse relationships between the calculated proton affinities and corresponding entropy similarities of experimental and CIDMD-predicted MS/MS spectra. CIDMD-predicted mechanistic details of fragmentation reaction pathways revealed a clear preference for specific protomer forms for several molecules. Overall, however, proton affinity was not a good predictor corresponding to the predicted CIDMD spectra. For example, for uracil, only one protomer predicted all experimental MS/MS fragment ions, but this protomer had neither the highest proton affinity nor the best MS/MS match score. Instead of proton affinity, the transfer of protons during the electrospray process from the initial protonation site (i.e., mobile proton model) better explains the differences between the thermodynamic rationale and experimental data. Protomers that undergo fragmentation with lower energy barriers have greater contributions to experimental MS/MS spectra than their thermodynamic Boltzmann populations would suggest. Hence, in silico predictions still need to calculate MS/MS spectra for multiple protomers, as the extent of distributions cannot be readily predicted.
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Affiliation(s)
- Jesi Lee
- Department of Chemistry, University of California, Davis, California 95616, United States
- West Coast Metabolomics Center, University of California, Davis, California 95616, United States
| | - Dean Joseph Tantillo
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Lee-Ping Wang
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Oliver Fiehn
- West Coast Metabolomics Center, University of California, Davis, California 95616, United States
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2
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Basuri P, Safferthal M, Kovacevic B, Schorr P, Riedel J, Pagel K, Volmer DA. Characterization of Anticancer Drug Protomers Using Electrospray Ionization and Ion Mobility Spectrometry-Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024. [PMID: 39355976 DOI: 10.1021/jasms.4c00233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2024]
Abstract
We used electrospray ionization and ion mobility spectrometry-mass spectrometry to detect and characterize the three anticancer drugs palbociclib, copanlisib, and olaparib. Ion mobility-mass spectrometry and density functional theory revealed that these compounds generate isomers during ionization (protomers) due to the presence of multiple protonation sites within their chemical structures. Our work has implications for understanding the solution- and gas-phase chemistry of these molecules during spray-based ionization processes.
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Affiliation(s)
- Pallab Basuri
- Institute of Chemistry, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Marc Safferthal
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Borislav Kovacevic
- Division of Physical Chemistry, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Pascal Schorr
- Institute of Chemistry, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Jerome Riedel
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Kevin Pagel
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Dietrich A Volmer
- Institute of Chemistry, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
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3
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Johnson CR, Sabatini HM, Aderorho R, Chouinard CD. Dependency of fentanyl analogue protomer ratios on solvent conditions as measured by ion mobility-mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2024; 59:e5070. [PMID: 38989742 DOI: 10.1002/jms.5070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/13/2024] [Accepted: 06/18/2024] [Indexed: 07/12/2024]
Abstract
Recently, our group has shown that fentanyl and many of its analogues form prototropic isomers ("protomers") during electrospray ionization. These different protomers can be resolved using ion mobility spectrometry and annotated using mobility-aligned tandem mass spectrometry fragmentation. However, their formation and the extent to which experimental variables contribute to their relative ratio remain poorly understood. In the present study, we systematically investigated the effects of mixtures of common chromatographic solvents (water, methanol, and acetonitrile) and pH on the ratio of previously observed protomers for 23 fentanyl analogues. Interestingly, these ratios (N-piperidine protonation vs. secondary amine/O = protonation) decreased significantly for many analogues (e.g., despropionyl ortho-, meta-, and para-methyl fentanyl), increased significantly for others (e.g., cis-isofentanyl), and remained relatively constant for the others as solvent conditions changed from 100% organic solvent (methanol or acetonitrile) to 100% water. Interestingly, pH also had significant effects on this ratio, causing the change in ratio to switch in many cases. Lastly, increasing conditions to pH ≥ 4.0 also prompted the appearance of new mobility peaks for ortho- and para-methyl acetyl fentanyl, where all previous studies had only showed one single distribution. Because these ratios have promise to be used qualitatively for identification of these (and emerging) fentanyl analogues, understanding how various conditions (i.e., mobile phase selection and/or chromatographic gradient) affect their ratios is critically important to the development of advanced ion mobility and mass spectrometry methodologies to identify fentanyl analogues.
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Affiliation(s)
| | - Heidi M Sabatini
- Department of Chemistry, Clemson University, Clemson, SC, USA, 29634
| | - Ralph Aderorho
- Department of Chemistry, Clemson University, Clemson, SC, USA, 29634
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4
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Kumar M, Attygalle AB. Manipulating Non-Dissociative Transformations of Gaseous Ion Ensembles Prior to Ion-Mobility Separation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:1197-1207. [PMID: 38718179 DOI: 10.1021/jasms.4c00032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Molecules with multiple sites capable of accepting protons form ensembles of protomers. The manifested protomer ratios in such ensembles are influenced by many experimental conditions. In a Synapt G2 ion mobility (IM)-enabled mass spectrometry system, there are several physical locations where ion population changes can be manifested. Using APCI-generated protomers of aminonaphthalenes, we investigated its intramolecular proton transfers from the N-protomer to the C-protomer. This lossless transformation of the N-protomer to the thermodynamically favored C-protomer can take place in the ion source itself. Initially, we learned that the cone gas slows down the transformation to the C-protomer. Gaseous ions are then accelerated in the first vacuum region, where ions undergo collisional activation (heating), which facilitates the transformation to the C-protomer. Afterward, the ions are mass selected and transferred to the pre-IM (Trap)-collision cell, where ions can also be transformed to the thermodynamically favored protomers. Trap accumulated ions are then released to the IM separator via a helium-filled entry cell. The role of helium is to minimize ion activation and scattering taking place upon entry to the high-pressure T-Wave IM separator (TWIMS). The helium cell is known to increase the IM peak resolution. However, we found that significant changes occur depending on the presence or absence of helium. Without helium, source-generated protomers rapidly changed to a predominantly thermodynamically favorable ensemble protomers. Apparently, the introduction of helium into the precell induced a dramatic decrease in collisional "heating" effect, which effectively slowed down the conversion rate of the amino-protomer into the more favorable ring-protomer. The final message is that mobilograms should not be considered as direct real-time, or intrinsic, representations of the protomer ratios in the ion source.
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Affiliation(s)
- Meenu Kumar
- 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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5
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Ucur B, Shiels OJ, Blanksby SJ, Trevitt AJ. Observation of Solvent-Dependence in the Mechanism of Neutral-Catalyzed Isomerization of para-Aminobenzoic Acid Protomers. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:1128-1137. [PMID: 38523556 DOI: 10.1021/jasms.3c00433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
Proton-transfer reactions are commonplace during electrospray ionization (ESI) mass spectrometry experiments and are often responsible for imparting charge to analyte molecules. Multiple protonation-site isomers (protomers) can arise for polyfunctional molecules and these isomers can interconvert via solvent-mediated proton transfer reactions during various stages of the ESI process. Studying the populations and interconversion of protonation isomers provides key insight into the ESI process, ion-molecule interactions, and ion dissociation mechanisms. An archetype molecule to study protomer interconversion fundamentals in this context is para-aminobenzoic acid (pABA), where both the amino and carboxylic acid protomers are typically formed under ESI and the mechanisms for interconversion are still under refinement. Using ion-trap mass spectrometry reaction kinetics (2.5 mTorr, 300 K), this study examines gas-phase interconversion catalysis of pABA protomers by seven neutral species, which are commen solvents and additives used for ESI: water, formic acid, methanol, ethanol, propanol, ammonia, and acetonitrile. Three distinct reaction cases are reported: (i) formic acid, methanol, ethanol, propanol, and ammonia each catalyze the interconversion between the amino and carboxylic acid protomers via a n = 1 solvent-molecule vehicle mechanism; (ii) for water, however, a n = 6 adduct complex is detected and this suggests that the observed protomer interconversion occurs through a Grotthuss mechanism, in accord with literature reports; (iii) acetonitrile inhibits proton transfer by the formation of particularly stable n = 1 and 2 adduct complexes. The second-order rate constants for the protomer interconversion are observed to increase in the following order: H2O < HCO2H < MeOH < EtOH < PrOH < NH3. Potential energy schemes are reported for all neutral-catalyzed proton transfer reactions using the DSD-PBEP86-D3(BJ)/aug-cc-pVDZ level of theory. A central transition state, which connects the protonation site adducts, is shown to be the key rate-limiting step. The energy of this transition state is sensitive to the proton affinity of the neutral solvent, and this is supported by the correlation between the reaction rate and the solvent proton affinity.
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Affiliation(s)
- Boris Ucur
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Oisin J Shiels
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Stephen J Blanksby
- Central Analytical Research Facility and the School of Chemistry and Physics, Queensland University of Technology, Brisbane 4001, Australia
| | - Adam J Trevitt
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
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6
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Reis A, Eberlin MN. A general, most basic rule for ion dissociation: Ionized molecules. JOURNAL OF MASS SPECTROMETRY : JMS 2024; 59:e5012. [PMID: 38639104 DOI: 10.1002/jms.5012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/18/2024] [Accepted: 02/13/2024] [Indexed: 04/20/2024]
Abstract
Herein we revisit a basic rule for the interpretation of ion chemistry of ionized molecules, first proposed by the pioneers of MS spectra interpretation, but somewhat overlooked over the years. This rule states that, when rationalizing or predicting the dissociation chemistry of an ionized molecule (M+.), a model analog to the "mobile proton model," that is, a "mobile electron model" via "e--jumping" should be considered. Ground-state M+. is indeed the first species to be considered, but "e--jumping" may eventually lead to other more energetic electromers-ionized molecules that differ only in the location of the missing electron-and each one of these electromers may dissociate via distinctive routes. In such a scenario, the route involving not necessarily the ground-state M+., but the most labile electromer could become predominant or even exclusive. We argue that this "most labile electromer" rule, as well as an analogous "most labile protomer" rule that we have proposed for protonated molecules in an accompanying article, with the application of our conventional toolbox of a few cleavages and rearrangements, greatly simplifies the interpretation and prediction of ion chemistry.
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Affiliation(s)
- Adriano Reis
- School of Engineering, Mackenzie Presbyterian University, São Paulo, SP, Brazil
- Mackenzie Institute for Research in Graphene and Nanotechnologies (MackGraphe), São Paulo, SP, Brazil
| | - Marcos N Eberlin
- School of Engineering, Mackenzie Presbyterian University, São Paulo, SP, Brazil
- Mackenzie Institute for Research in Graphene and Nanotechnologies (MackGraphe), São Paulo, SP, Brazil
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7
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Reis A, Augusti R, Eberlin MN. A general, most basic rule for ion dissociation: Protonated molecules. JOURNAL OF MASS SPECTROMETRY : JMS 2024; 59:e5003. [PMID: 38445745 DOI: 10.1002/jms.5003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/03/2024] [Accepted: 01/11/2024] [Indexed: 03/07/2024]
Abstract
Contrary to the common but potentially misleading belief that when a protonated molecule is excited, it is its most stable protomer that will mandatorily dissociate, we demonstrate herein that, when rationalizing or predicting the chemistry of such ions, we should always search for the most labile protomer. This "most labile protomer" rule, based on the mobile proton model, states therefore that when a protonated molecule is heated, during ionization or by collisions for instance, the loosely bonded proton (H+ ) can acquire enough energy to detach itself from the most basic site of the molecule and then freely "walk through" the molecular framework to eventually find, if available, another protonation site, forming other less stable but more labile protomers, that is, protomers that may display lower dissociation thresholds. To demonstrate the validity of the "most labile protomer" rule as well as the misleading nature of the "most stable protomer" rule, we have selected several illustrative molecules and have collected their ESI(+)-MS/MS. To compare energies of precursors and products, we have also performed PM7 calculations and elaborated potential energy surface diagrams for their possible protomers and dissociation thresholds. We have also applied the "most labile protomer" rule to reinterpret-exclusively via classical charge-induced dissociation cleavages-several dissociation processes proposed for protonated molecules. In an accompanying letter, we have also applied a similar "most labile electromer" rule to ionized molecules.
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Affiliation(s)
- Adriano Reis
- School of Engineering, Mackenzie Presbyterian University, São Paulo, SP, Brazil
- Mackenzie Institute for Research in Graphene and Nanotechnologies (MackGraphe), São Paulo, SP, Brazil
| | - Rodinei Augusti
- Department of Chemistry, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Marcos N Eberlin
- School of Engineering, Mackenzie Presbyterian University, São Paulo, SP, Brazil
- Mackenzie Institute for Research in Graphene and Nanotechnologies (MackGraphe), São Paulo, SP, Brazil
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8
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Habeck T, Maciel EVS, Kretschmer K, Lermyte F. Charge site manipulation to enhance top-down fragmentation efficiency. Proteomics 2024; 24:e2300082. [PMID: 37043727 DOI: 10.1002/pmic.202300082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 04/14/2023]
Abstract
In recent years, top-down mass spectrometry has become a widely used approach to study proteoforms; however, improving sequence coverage remains an important goal. Here, two different proteins, α-synuclein and bovine carbonic anhydrase, were subjected to top-down collision-induced dissociation (CID) after electrospray ionisation. Two high-boiling solvents, DMSO and propylene carbonate, were added to the protein solution in low concentration (2%) and the effects on the top-down fragmentation patterns of the proteins were systematically investigated. Each sample was measured in triplicate, which revealed highly reproducible differences in the top-down CID fragmentation patterns in the presence of a solution additive, even if the same precursor charge state was isolated in the quadrupole of the instrument. Further investigation supports the solution condition-dependent selective formation of different protonation site isomers as the underlying cause of these differences. Higher sequence coverage was often observed in the presence of additives, and the benefits of this approach became even more evident when datasets from different solution conditions were combined, as increases up to 35% in cleavage coverage were obtained. Overall, this approach therefore represents a promising opportunity to increase top-down fragmentation efficiency.
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Affiliation(s)
- Tanja Habeck
- Department of Chemistry, Clemens-Schöpf-Institute of Chemistry and Biochemistry, Technical University of Darmstadt, Darmstadt, Hessen, Germany
| | - Edvaldo Vasconcelos Soares Maciel
- Department of Chemistry, Clemens-Schöpf-Institute of Chemistry and Biochemistry, Technical University of Darmstadt, Darmstadt, Hessen, Germany
| | - Kevin Kretschmer
- Department of Chemistry, Clemens-Schöpf-Institute of Chemistry and Biochemistry, Technical University of Darmstadt, Darmstadt, Hessen, Germany
| | - Frederik Lermyte
- Department of Chemistry, Clemens-Schöpf-Institute of Chemistry and Biochemistry, Technical University of Darmstadt, Darmstadt, Hessen, Germany
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9
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Majeed HA, Bos TS, Voeten RLC, Kranenburg RF, van Asten AC, Somsen GW, Kohler I. Trapped ion mobility mass spectrometry of new psychoactive substances: Isomer-specific identification of ring-substituted cathinones. Anal Chim Acta 2023; 1264:341276. [PMID: 37230720 DOI: 10.1016/j.aca.2023.341276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/18/2023] [Accepted: 04/23/2023] [Indexed: 05/27/2023]
Abstract
New psychoactive substances (NPS) are synthetic derivatives of illicit drugs designed to mimic their psychoactive effects. NPS are typically not controlled under drug acts or their legal status depends on their molecular structure. Discriminating isomeric forms of NPS is therefore crucial for forensic laboratories. In this study, a trapped ion mobility spectrometry time-of-flight mass spectrometry (TIMS-TOFMS) approach was developed for the identification of ring-positional isomers of synthetic cathinones, a class of compounds representing two-third of all NPS seized in Europe in 2020. The optimized workflow features narrow ion-trapping regions, mobility calibration by internal reference, and a dedicated data-analysis tool, allowing for accurate relative ion-mobility assessment and high-confidence isomer identification. Ortho-, meta- and para-isomers of methylmethcathinone (MMC) and bicyclic ring isomers of methylone were assigned based on their specific ion mobilities within 5 min, including sample preparation and data analysis. The resolution of two distinct protomers per cathinone isomer added to the confidence in identification. The developed approach was successfully applied to the unambiguous assignment of MMC isomers in confiscated street samples. These findings demonstrate the potential of TIMS-TOFMS for forensic case work requiring fast and highly-confident assignment cathinone-drug isomers in confiscated samples.
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Affiliation(s)
- Hany A Majeed
- Division of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands; Centre for Analytical Sciences Amsterdam (CASA), 1098 XH, Amsterdam, the Netherlands
| | - Tijmen S Bos
- Division of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands; Centre for Analytical Sciences Amsterdam (CASA), 1098 XH, Amsterdam, the Netherlands
| | - Robert L C Voeten
- Division of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands; Centre for Analytical Sciences Amsterdam (CASA), 1098 XH, Amsterdam, the Netherlands
| | - Ruben F Kranenburg
- Centre for Analytical Sciences Amsterdam (CASA), 1098 XH, Amsterdam, the Netherlands; Forensic Laboratory, Unit Amsterdam, Dutch National Police, Kabelweg 25, 1014 BA, Amsterdam, the Netherlands; Van't Hoff Institute for Molecular Sciences, University of Amsterdam, P.O. Box 94157, 1090 GD, Amsterdam, the Netherlands
| | - Arian C van Asten
- Centre for Analytical Sciences Amsterdam (CASA), 1098 XH, Amsterdam, the Netherlands; Van't Hoff Institute for Molecular Sciences, University of Amsterdam, P.O. Box 94157, 1090 GD, Amsterdam, the Netherlands; Co van Ledden Hulsebosch Center (CLHC), Amsterdam Center for Forensic Science and Medicine, P.O. Box 94157, 1090 GD, Amsterdam, the Netherlands
| | - Govert W Somsen
- Division of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands; Centre for Analytical Sciences Amsterdam (CASA), 1098 XH, Amsterdam, the Netherlands
| | - Isabelle Kohler
- Division of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands; Centre for Analytical Sciences Amsterdam (CASA), 1098 XH, Amsterdam, the Netherlands; Co van Ledden Hulsebosch Center (CLHC), Amsterdam Center for Forensic Science and Medicine, P.O. Box 94157, 1090 GD, Amsterdam, the Netherlands.
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10
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Lin C, Zhou X, Zhang H, Fu Z, Yang H, Zhang M, Hu P. Deciphering and investigating fragment mechanism of quinolones using multi-collision energy mass spectrometry and computational chemistry strategy. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2023; 37:e9514. [PMID: 37012644 DOI: 10.1002/rcm.9514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 03/28/2023] [Accepted: 03/29/2023] [Indexed: 05/17/2023]
Abstract
RATIONALE Quinolones show characteristic fragments in mass spectrometry (MS) analysis due to their common core structures, and energy-dependent differences among these fragments are generated through the same fragmentation pathway of different molecules. Computational chemistry, which provides quantitative results of molecule parameters, is helpful for investigating the mechanisms of chemistry. METHODS MS/MS spectra of five quinolones, namely norfloxacin (NOR), enoxacin (ENO), enrofloxacin (ENR), gatifloxacin (GAT), and lomefloxacin (LOM), were acquired for deciphering fragmentation pathways under multi-collision energy (CE). Computational methods were used for excluding little possibility pathways from the point of view of energy and stable conformations, whereas optimized collision energy (OCE) and maximum relative intensity (MRI) of major competitive fragments were investigated and confirmed using computational results. RESULTS Fragmentation results of NOR, ENO, ENR, and GAT were deciphered using experimental and computational data, of which fragmentation regularities were summarized. Fragmentation pathways of LOM were deciphered under the guidance of foregoing regularities. Meanwhile, the whole process was validated by comparing OCE and MRI and computational energy results, which showed good agreement. CONCLUSIONS A strategy for explaining quinolone fragmentation results of multi-CE values and deciphering fragment mechanism using computational methods was developed. Relevant data and strategy may provide ideas for how to design and decipher new drug molecules with similar structures.
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Affiliation(s)
- Chuhui Lin
- Shanghai Key Laboratory of Functional Materials Chemistry, Department of Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Meilong road No.130, Shanghai, China
| | - Xudong Zhou
- Shanghai Key Laboratory of Functional Materials Chemistry, Department of Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Meilong road No.130, Shanghai, China
| | - Hongyang Zhang
- Shanghai Key Laboratory of Functional Materials Chemistry, Department of Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Meilong road No.130, Shanghai, China
| | - Zhibo Fu
- Shanghai Key Laboratory of Functional Materials Chemistry, Department of Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Meilong road No.130, Shanghai, China
| | - Haoyu Yang
- Shanghai Key Laboratory of Functional Materials Chemistry, Department of Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Meilong road No.130, Shanghai, China
| | - Min Zhang
- Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, Department of pharmaceutical engineering, School of Pharmacy, East China University of Science and Technology, Meilong road No.130, Shanghai, China
| | - Ping Hu
- Shanghai Key Laboratory of Functional Materials Chemistry, Department of Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Meilong road No.130, Shanghai, China
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11
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Simón-Manso Y. Ion-Neutral Collision Cross Section as a Function of the Static Dipole Polarizability and the Ionization Energy of the Ion. J Phys Chem A 2023; 127:3274-3280. [PMID: 37019437 PMCID: PMC10550215 DOI: 10.1021/acs.jpca.2c07157] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Ion mobility spectrometry is becoming more and more popular as a fast, efficient, and sensitive tool for the separation and identification of ionized molecules in the gas phase. An ion traveling through a drift tube at atmospheric pressure under the influence of an electric field collides with the buffer gas molecules. The mobility of the ion depends inversely on the ion-neutral collision cross section. In the simplest hard-sphere approximation, the collision cross section is the area of the conventional geometric cross section. However, deviations are expected because of the physical interactions between the colliding species. More than a century ago, Langevin described a model for the interaction between a point-charge ion and a polarizable atom (molecule). Since then, the model has been modified many times to include better approximations of the interaction potential, usually preserving the point-charge nature of the ion. Although more advanced approaches allow for considering polarizable ions with dissimilar sizes and shapes, still explicit analytical dependencies on the properties of the ion remain elusive. In this work, an extended version of the Langevin model is proposed and solved using algebraic perturbation theory. A simple analytical expression of the collision cross section depending explicitly on both the static dipole polarizability and the ionization energy of the ion is found. The equation is validated using ion mobility data. Surprisingly, even low-level calculations of the polarizability tensors produce results that are consistent with the experimental observations. This fact makes the equation very attractive for helping applications in different areas, such as the deconvolution of mobilograms of protomers, ion-molecule chemical kinetics, and others.
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Affiliation(s)
- Yamil Simón-Manso
- Mass Spectrometry Data Center, Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
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12
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de Bruin CR, Hennebelle M, Vincken JP, de Bruijn WJC. Separation of flavonoid isomers by cyclic ion mobility mass spectrometry. Anal Chim Acta 2023; 1244:340774. [PMID: 36737151 DOI: 10.1016/j.aca.2022.340774] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/21/2022] [Accepted: 12/30/2022] [Indexed: 12/31/2022]
Abstract
Analytical techniques, such as liquid chromatography coupled to mass spectrometry (LC-MS) or nuclear magnetic resonance (NMR), are widely used for characterization of complex mixtures of (isomeric) proteins, carbohydrates, lipids, and phytochemicals in food. Food can contain isomers that are challenging to separate, but can possess different reactivity and bioactivity. Catechins are the main phenolic compounds in tea; they can be present as various stereoisomers, which differ in their chemical properties. Currently, there is a lack of fast and direct methods to monitor interconversion and individual reactivity of these epimers (e.g. epicatechin (EC) and catechin (C)). In this study, cyclic ion mobility mass spectrometry (cIMS-MS) was explored as a potential tool for the separation of catechin epimers. Formation of sodium and lithium adducts enhanced IMS separation of catechin epimers, compared to deprotonation and protonation. Baseline separation of the sodium adducts of catechin epimers was achieved. Moreover, we developed a fast method for the identification and semi-quantification of cIMS-MS separated catechin epimers. With this method, it is possible to semi-quantify the ratio between EC and C (1:5 to 5:1, within 50-1200 ng mL-1) in food samples, such as tea. Finally, the newly developed approach for cIMS-MS separation of flavonoids was demonstrated to be successful in separation of two sets of positional isomers (i.e. morin, tricetin, and quercetin; and kaempferol, fisetin, luteolin, and scutellarein). To conclude, we showed that both epimers and positional isomers of flavonoids can be separated using cIMS-MS, and established the potential of this method for challenging flavonoid separations.
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Affiliation(s)
- Carlo Roberto de Bruin
- Laboratory of Food Chemistry, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, the Netherlands
| | - Marie Hennebelle
- Laboratory of Food Chemistry, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, the Netherlands
| | - Jean-Paul Vincken
- Laboratory of Food Chemistry, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, the Netherlands
| | - Wouter J C de Bruijn
- Laboratory of Food Chemistry, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, the Netherlands.
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13
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Fu D, Habtegabir SG, Wang H, Feng S, Han Y. Understanding of protomers/deprotomers by combining mass spectrometry and computation. Anal Bioanal Chem 2023:10.1007/s00216-023-04574-1. [PMID: 36737499 DOI: 10.1007/s00216-023-04574-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/19/2023] [Accepted: 01/27/2023] [Indexed: 02/05/2023]
Abstract
Multifunctional compounds may form different prototropic isomers under different conditions, which are known as protomers/deprotomers. In biological systems, these protomer/deprotomer isomers affect the interaction modes and conformational landscape between compounds and enzymes and thus present different biological activities. Study on protomers/deprotomers is essentially the study on the acidity/basicity of each intramolecular functional group and its effect on molecular structure. In recent years, the combination of mass spectrometry (MS) and computational chemistry has been proven to be a powerful and effective means to study prototropic isomers. MS-based technologies are developed to discriminate and characterize protomers/deprotomers to provide structural information and monitor transformations, showing great superiority than other experimental methods. Computational chemistry is used to predict the thermodynamic stability of protomers/deprotomers, provide the simulated MS/MS spectra, infrared spectra, and calculate collision cross-section values. By comparing the theoretical data with the corresponding experimental results, the researchers can not only determine the protomer/deprotomer structure, but also investigate the structure-activity relationship in a given system. This review covers various MS methods and theoretical calculations and their devotion to isomer discrimination, structure identification, conformational transformation, and phase transition investigation of protomers/deprotomers.
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Affiliation(s)
- Dali Fu
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering and Environment, China University of Petroleum-Beijing, Beijing, 102249, People's Republic of China
| | - Sara Girmay Habtegabir
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering and Environment, China University of Petroleum-Beijing, Beijing, 102249, People's Republic of China
| | - Haodong Wang
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering and Environment, China University of Petroleum-Beijing, Beijing, 102249, People's Republic of China
| | - Shijie Feng
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering and Environment, China University of Petroleum-Beijing, Beijing, 102249, People's Republic of China
| | - Yehua Han
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering and Environment, China University of Petroleum-Beijing, Beijing, 102249, People's Republic of China.
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14
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Oliveira CX, Costa FLP, Mota GVS. Fragmentation route of doubly ionized benzene, aniline, and nitroanilines monomers using a novel protocol from density functional theory and QTAIM. J Mol Model 2023; 29:53. [PMID: 36700984 DOI: 10.1007/s00894-023-05461-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 01/20/2023] [Indexed: 01/27/2023]
Abstract
The possibility of finding the fragmentation routes by theoretical methods led us to compare the molecular ions between neutral molecules of benzene, aniline, and o-, m-, and p-nitroaniline, using the density functional theory (DFT), under an aug-cc-pVDZ base set and a B3LYP exchange-correlation functional. After determining the structure and electronic energy of neutral and doubly ionized species, we used a new protocol based on analyzing Wiberg's binding indexes and the quantum theory of atoms in Bader molecules (QTAIM). The charge transfer and electronic distribution in aromatic monomers indicate the possibility of fragment formation in at least two pairs of carbon-carbon (CC) atoms. They show the possible loss of the -CNH2 and -NO2 groups in the aniline and nitroaniline molecules doubly ionized.
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Affiliation(s)
- Carlos X Oliveira
- Department of Physics, UnB, Campus Darcy Ribeiro, Brasilia-DF, Brazil
| | | | - Gunar V S Mota
- Faculty of Natural Science, Institute of Exact and Natural Sciences, UFPA, Belem, PA, Brazil.
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15
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Analytical key issues and challenges in the LC-MS/MS determination of antibiotics in wastewater. Anal Chim Acta 2023; 1239:340739. [PMID: 36628733 DOI: 10.1016/j.aca.2022.340739] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/15/2022] [Accepted: 12/21/2022] [Indexed: 12/27/2022]
Abstract
The research on antibiotics occurrence in the aquatic environment has become a hot topic in the last years due to their potential negative effects, associated to possible bacterial antibiotic-resistance, after continuous exposure to these compounds. Most of antibiotic residues are not completely removed in the wastewater treatment plants (WWTPs) and end up in the aquatic environment through treated wastewater (WW). The development of reliable analytical methodologies for the determination of antibiotics in influent (IWW) and effluent wastewater (EWW) is needed with different purposes, among others: monitoring their occurrence in the aquatic environment, performing environmental risk assessment, estimating removal efficiencies of WWTPs, or estimating the consumption of these compounds. In this paper, we perform an in-depth investigation on analytical key issues that pose difficulties in the determination of antibiotics in complex matrices, such as WW, and we identify challenges to be properly addressed for successful analysis. The analytical technique selected was liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), as it is the most powerful and widely applied at present for antibiotic residues determination. The mass spectrometric behavior of 18 selected antibiotics, the chromatographic performance, ion ratio variations associated to the sample matrix when using different precursor ions or protomers, and the macrolides adsorption to glass vial, were some of the issues studied in this work. On the basis of the detailed study performed, an analytical LC-MS/MS method based on sample direct injection has been developed for quantification of 18 antibiotics in IWW and EWW, allowing their determination at low ng L-1 levels.
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16
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Meng Y, Gnanamani E, Zare RN. Catalyst-Free Decarboxylative Amination of Carboxylic Acids in Water Microdroplets. J Am Chem Soc 2023; 145:32-36. [PMID: 36566437 DOI: 10.1021/jacs.2c12236] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Previous studies have shown that hydroxyl radicals can be formed at the water-gas surface of water microdroplets. We report the use of in situ generated hydroxyl radicals to carry out an organic transformation in one step, namely, the formation of anilines from aryl acids as well as both ammonia and primary/secondary amines via decarboxylation. Benzoic acids and amines are dissolved in water, and the solution is sprayed to form microdroplets whose chemical contents are analyzed mass spectrometrically. All intermediates and products are determined using mass spectrometry (MS) as well as in some cases tandem mass spectrometry (MS2). These results support the following reaction mechanism: NR2OH, formed via reaction of the amine with •OH, reacts with benzoic acid to form an isocyanate via a Lossen rearrangement. Hydrolysis followed by liberation of CO2 then delivers the aniline product. Notably, the scope of this transformation includes a variety of amines and aromatic acids and enables their conversion into aniline and N-substituted anilines, all in a single step. Additionally, this reaction occurs at room temperature and does not require metal catalysts or organic solvents.
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Affiliation(s)
- Yifan Meng
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Elumalai Gnanamani
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India
| | - Richard N Zare
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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17
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Naylor CN, Schaefer C, Kirk AT, Zimmermann S. The origin of isomerization of aniline revealed by high kinetic energy ion mobility spectrometry (HiKE-IMS). Phys Chem Chem Phys 2023; 25:1139-1152. [PMID: 36515135 DOI: 10.1039/d2cp01994a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Although aniline is a relatively simple small molecule, the origin of its two peaks observed in ion mobility spectrometry (IMS) has remained under debate for at least 30 years. First hypothesized as a difference in protonation site (amine vs. benzene ring), each ion mobility peak differs by one Dalton when coupled with mass spectrometry where the faster mobility peak is the molecular ion peak, and the slower mobility peak is protonated. To complicate the deconvolution of structures, some previous literature shows the peaks as unresolved and thus proposes these species exist in equilibrium. In this work, we show that when measured with high kinetic energy ion mobility spectrometry (HiKE-IMS), the two peaks observed in spectra of both aniline and all n-fluoroanilines are fully separated (chromatographic resolution from 2-7, Rp > 110) and therefore not in equilibrium. The HiKE-IMS is capable of changing ionization conditions independently of drift region conditions, and our results agree with previous literature showing that ionization source settings (including possible fragmentation at this stage) are the only influence determining the speciation of the two aniline peaks. Finally, when the drift and reactant gas are changed to nitrogen, a third peak appears at high E/N for 2-fluoroaniline and 4-fluoroaniline for the first time in reported literature. As observed by HiKE-IMS-MS, the new third peak is also protonated showing that the para-protonated aniline and resulting fragment ion, molecular ion aniline, can be fully separated in the mobility domain for the first time. The appearance of the third peak is only possible due to the increased separation of the other two peaks within the HiKE-IMS.
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Affiliation(s)
- Cameron N Naylor
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, 30167 Hannover, Germany.
| | - Christoph Schaefer
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, 30167 Hannover, Germany.
| | - Ansgar T Kirk
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, 30167 Hannover, Germany.
| | - Stefan Zimmermann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, 30167 Hannover, Germany.
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18
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Koopman J, Grimme S. Calculation of Mass Spectra with the QCxMS Method for Negatively and Multiply Charged Molecules. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:2226-2242. [PMID: 36343304 DOI: 10.1021/jasms.2c00209] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Analysis and validation of a mass spectrometry (MS) experiment are usually performed by comparison to reference spectra. However, if references are missing, measured spectra cannot be properly matched. To close this gap, the Quantum Chemical Mass Spectrometry (QCxMS) program has been developed. It enables fully automatic calculations of electron ionization (EI) and positive ion collision-induced dissociation (CID) mass spectra of singly charged molecular ions. In this work, the extension to negative and multiple ion charge for the CID run mode is presented. QCxMS is now capable of calculating structures carrying any charge, without the need for pretabulated fragmentation pathways or machine learning of database spectra. Mass spectra of four single negatively charged and two multiple positively charged organic ions with molecular sizes from 12 to 92 atoms were computed and compared to reference spectra. The underlying Born-Oppenheimer molecular dynamics (MD) calculations were conducted using the semiempirical quantum mechanical GFN2-xTB method, while for some small molecules, ab initio DFT-based MD simulations were performed. Detailed insights into the fragmentation pathways were gained, and the effects of the computed charge assignments on the resulting spectrum are discussed. Especially for the negative ion mode, the influence of the deprotonation site to create the anion was found to be substantial. Doubly charged fragments could successfully be calculated fully automatically for the first time, while higher charged structures introduced severe assignment problems. Overall, this extension of the QCxMS program further enhances its applicability and underlines its value as a sophisticated toolkit for CID-based tandem MS structure elucidation.
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Affiliation(s)
- Jeroen Koopman
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115Bonn, Germany
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19
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May JC, McLean JA. Integrating ion mobility into comprehensive multidimensional metabolomics workflows: critical considerations. Metabolomics 2022; 18:104. [PMID: 36472678 DOI: 10.1007/s11306-022-01961-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 11/18/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Ion mobility (IM) separation capabilities are now widely available to researchers through several commercial vendors and are now being adopted into many metabolomics workflows. The added peak capacity that ion mobility offers with minimal compromise to other analytical figures-of-merit has provided real benefits to sensitivity and structural selectivity and have allowed more specific metabolite annotations to be assigned in untargeted workflows. One of the greatest promises of contemporary IM-enabled instrumentation is the capability of operating multiple analytical dimensions inline with minimal sample volumes, which has the potential to address many grand challenges currently faced in the omics fields. However, comprehensive operation of multidimensional mass spectrometry comes with its own inherent challenges that, beyond operational complexity, may not be immediately obvious to practitioners of these techniques. AIM OF REVIEW In this review, we outline the strengths and considerations for incorporating IM analysis in metabolomics workflows and provide a critical but forward-looking perspective on the contemporary challenges and prospects associated with interpreting IM data into chemical knowledge. KEY SCIENTIFIC CONCEPTS OF REVIEW We outline a strategy for unifying IM-derived collision cross section (CCS) measurements obtained from different IM techniques and discuss the emerging field of high resolution ion mobility (HRIM) that is poised to address many of the contemporary challenges associated with ion mobility metabolomics. Whereas the LC step limits the throughput of comprehensive LC-IM-MS, the higher peak capacity of HRIM can allow fast LC gradients or rapid sample cleanup via solid-phase extraction (SPE) to be utilized, significantly improving the sample throughput.
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Affiliation(s)
- Jody C May
- Center for Innovative Technology, Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - John A McLean
- Center for Innovative Technology, Department of Chemistry, Vanderbilt University, Nashville, TN, USA.
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20
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Tammiku-Taul J, Burk P. Nonempirical Prediction of the Relative Electrospray Ionization Efficiencies of Nitroanilines by Combined CBS-QB3 and SCC-DFTB Calculations. J Phys Chem A 2022; 126:8939-8944. [DOI: 10.1021/acs.jpca.2c05420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Jaana Tammiku-Taul
- Institute of Chemistry, University of Tartu, Ravila 14A, Tartu 50411, Estonia
| | - Peeter Burk
- Institute of Chemistry, University of Tartu, Ravila 14A, Tartu 50411, Estonia
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21
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Sabino AA, Chanteau SH, Henrique Astolfi Ferreira J, Camacho Santos A, Canevari TC, Tour JM, Eberlin MN. Fragmenting nanoPutians: Capturing admiration to the rationality, predictability, and beauty of ion chemistry in mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2022; 57:e4881. [PMID: 36102123 DOI: 10.1002/jms.4881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 08/03/2022] [Accepted: 08/06/2022] [Indexed: 06/15/2023]
Abstract
The fragmentation chemistry of the protonated and ionized nanoPutian 1 has been studied in the gas phase via electrospray ionization and tandem mass spectrometry. A direct analogy was observed between the fragmentation chemistry of this fascinating "humanoid molecule" and "cleavages" at certain parts of the human body. We argue that such direct analogy and illustrative schemes for the fragmentation of molecular ions of 1 offer a ludic and efficient tool to teach and capture attention to ion chemistry in mass spectrometry. Using the changes in mass for the two heavier nanoPutians with different head styles but the same body design, the analogy has also been used to predict mass spectra. The concepts of isotopic labelling and dissociation thresholds have also been illustrated. For many years, the approach has been successfully used by one of us in classes and lectures, mainly when presenting ion chemistry to students and audiences from fields other than Chemistry, most particularly from Biology, Medicine, and Forensic Chemistry.
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Affiliation(s)
- Adão A Sabino
- Institute of Chemistry - Federal University of Minas Gerais - UFMG, Belo Horizonte, MG, Brazil
| | - Stephanie H Chanteau
- Department of Chemistry, Department of Materials Science and NanoEngineering, the Smalley-Curl Institute and NanoCarbon Center, Rice University, Houston, Texas, USA
| | - João Henrique Astolfi Ferreira
- NAHM: Laboratory of Multifunctional Hybrid Nanomaterials - School of Engineering - PPGEMN, Mackenzie Presbyterian University, São Paulo, SP, Brazil
| | - Alicia Camacho Santos
- MackMass Laboratory for Mass Spectrometry, School of Engineering - PPGEMN, Mackenzie Presbyterian University, São Paulo, SP, Brazil
| | - Thiago C Canevari
- NAHM: Laboratory of Multifunctional Hybrid Nanomaterials - School of Engineering - PPGEMN, Mackenzie Presbyterian University, São Paulo, SP, Brazil
| | - James M Tour
- Department of Chemistry, Department of Materials Science and NanoEngineering, the Smalley-Curl Institute and NanoCarbon Center, Rice University, Houston, Texas, USA
| | - Marcos N Eberlin
- MackMass Laboratory for Mass Spectrometry, School of Engineering - PPGEMN, Mackenzie Presbyterian University, São Paulo, SP, Brazil
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22
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Paglia G, Smith AJ, Astarita G. Ion mobility mass spectrometry in the omics era: Challenges and opportunities for metabolomics and lipidomics. MASS SPECTROMETRY REVIEWS 2022; 41:722-765. [PMID: 33522625 DOI: 10.1002/mas.21686] [Citation(s) in RCA: 90] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 01/17/2021] [Accepted: 01/17/2021] [Indexed: 06/12/2023]
Abstract
Researchers worldwide are taking advantage of novel, commercially available, technologies, such as ion mobility mass spectrometry (IM-MS), for metabolomics and lipidomics applications in a variety of fields including life, biomedical, and food sciences. IM-MS provides three main technical advantages over traditional LC-MS workflows. Firstly, in addition to mass, IM-MS allows collision cross-section values to be measured for metabolites and lipids, a physicochemical identifier related to the chemical shape of an analyte that increases the confidence of identification. Second, IM-MS increases peak capacity and the signal-to-noise, improving fingerprinting as well as quantification, and better defining the spatial localization of metabolites and lipids in biological and food samples. Third, IM-MS can be coupled with various fragmentation modes, adding new tools to improve structural characterization and molecular annotation. Here, we review the state-of-the-art in IM-MS technologies and approaches utilized to support metabolomics and lipidomics applications and we assess the challenges and opportunities in this growing field.
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Affiliation(s)
- Giuseppe Paglia
- School of Medicine and Surgery, University of Milano-Bicocca, Vedano al Lambro (MB), Italy
| | - Andrew J Smith
- School of Medicine and Surgery, University of Milano-Bicocca, Vedano al Lambro (MB), Italy
| | - Giuseppe Astarita
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, District of Columbia, USA
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23
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Oluwatoba DS, Islam MF, Som B, Sindt AJ, Smith MD, Shimizu LS, Do TD. Evaluating the Effects of Metal Adduction and Charge Isomerism on Ion-Mobility Measurements using m-Xylene Macrocycles as Models. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:840-850. [PMID: 35471025 DOI: 10.1021/jasms.2c00033] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Gas-phase ion-mobility spectrometry provides a unique platform to study the effect of mobile charge(s) or charge location on collisional cross section and ion separation. Here, we evaluate the effects of cation/anion adduction in a series of xylene and pyridyl macrocycles that contain ureas and thioureas. We explore how zinc binding led to unexpected deprotonation of the thiourea macrocyclic host in positive polarity ionization and subsequently how charge isomerism due to cation (zinc metal) and anion (chloride counterion) adduction or proton competition among acceptors can affect the measured collisional cross sections in helium and nitrogen buffer gases. Our approach uses synthetic chemistry to design macrocycle targets and a combination of ion-mobility spectrometry mass spectrometry experiments and quantum mechanics calculations to characterize their structural properties. We demonstrate that charge isomerism significantly improves ion-mobility resolution and allows for determination of the metal binding mechanism in metal-inclusion macrocyclic complexes. Additionally, charge isomers can be populated in molecules where individual protons are shared between acceptors. In these cases, interactions via drift gas collisions magnify the conformational differences. Finally, for the macrocyclic systems we report here, charge isomers are observed in both helium and nitrogen drift gases with similar resolution. The separation factor does not simply increase with increasing drift gas polarizability. Our study sheds light on important properties of charge isomerism and offers strategies to take advantage of this phenomenon in analytical separations.
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Affiliation(s)
- Damilola S Oluwatoba
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Md Faizul Islam
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Bozumeh Som
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
- Department of Chemistry, University of Ghana, P.O. Box LG 56, Legon, Accra, Ghana
| | - Ammon J Sindt
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Mark D Smith
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Linda S Shimizu
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Thanh D Do
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
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24
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McCann A, Kune C, Massonnet P, Far J, Ongena M, Eppe G, Quinton L, De Pauw E. Cyclic Peptide Protomer Detection in the Gas Phase: Impact on CCS Measurement and Fragmentation Patterns. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:851-858. [PMID: 35467879 DOI: 10.1021/jasms.2c00035] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
With the recent improvements in ion mobility resolution, it is now possible to separate small protomeric tautomers, called protomers. In larger molecules above 1000 Da such as peptides, a few studies suggest that protomers do exist as well and may contribute to their gas-phase conformational heterogeneity. In this work, we observed a CCS distribution that can be explained by the presence of protomers of surfactin, a small lipopeptide with no basic site. Following preliminary density functional theoretical calculations, several protonation sites in the gas phase were energetically favorable in positive ionization mode. Experimentally, at least three near-resolved IM peaks were observed in positive ionization mode, while only one was detected in negative ionization mode. These results were in good agreement with the DFT predictions. CID breakdown curve analysis after IM separation showed different inflection points (CE50) suggesting that different intramolecular interactions were implied in the stabilization of the structures of surfactin. The fragment ratio observed after collision-induced fragmentation was also different, suggesting different ring-opening localizations. All these observations support the presence of protomers on the cyclic peptide moieties of the surfactin. These data strongly suggest that protomeric tautomerism can still be observed on molecules above 1000 Da if the IM resolving power is sufficient. It also supports that the proton localization involves a change in the 3D structure that can affect the experimental CCS and the fragmentation channels of such peptides.
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Affiliation(s)
- Andréa McCann
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
| | - Christopher Kune
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
| | - Philippe Massonnet
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
- Maastricht Multimodal Molecular Imaging (M4I) Institute, Division of Imaging Mass Spectrometry, 6229ER Maastricht, Limburg, The Netherlands
| | - Johann Far
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
| | - Marc Ongena
- Gembloux Agro-Bio Tech, University of Liege, 5030 Gembloux, Belgium
| | - Gauthier Eppe
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
| | - Loïc Quinton
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
| | - Edwin De Pauw
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, 4000 Liège, Belgium
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25
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Ucur B, Maccarone AT, Ellis SR, Blanksby SJ, Trevitt AJ. Solvent-Mediated Proton-Transfer Catalysis of the Gas-Phase Isomerization of Ciprofloxacin Protomers. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:347-354. [PMID: 35014802 DOI: 10.1021/jasms.1c00331] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Understanding how neutral molecules become protonated during positive-ion electrospray ionization (ESI) mass spectrometry is critically important to ensure analytes can be efficiently ionized, detected, and unambiguously identified. The ESI solvent is one of several parameters that can alter the dominant site of protonation in polyfunctional molecules and thus, in turn, can significantly change the collision-induced dissociation (CID) mass spectra relied upon for compound identification. Ciprofloxacin─a common fluoroquinolone antibiotic─is one such example whereby positive-ion ESI can result in gas-phase [M + H]+ ions protonated at either the keto-oxygen or the piperazine-nitrogen. Here, we demonstrate that these protonation isomers (or protomers) of ciprofloxacin can be resolved by differential ion mobility spectrometry and give rise to distinctive CID mass spectra following both charge-directed and charge-remote mechanisms. Interaction of mobility-selected protomers with methanol vapor (added via the throttle gas supply) was found to irreversibly convert the piperazine N-protomer to the keto-O-protomer. This methanol-mediated proton-transport catalysis is driven by the overall exothermicity of the reaction, which is computed to favor the O-protomer by 93 kJ mol-1 (in the gas phase). Conversely, gas phase interactions of mobility-selected ions with acetonitrile vapor selectively depletes the N-protomer ion signal as formation of stable [M + H + CH3CN]+ cluster ions skews the apparent protomer population ratio, as the O-protomer is unaffected. These findings provide a mechanistic basis for tuning protomer populations to ensure faithful characterization of multifunctional molecules by tandem mass spectrometry.
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Affiliation(s)
- Boris Ucur
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Alan T Maccarone
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Shane R Ellis
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522, Australia
| | - Stephen J Blanksby
- Central Analytical Research Facility and School of Chemistry and Physics, Queensland University of Technology, Brisbane 4001, Australia
| | - Adam J Trevitt
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
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26
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Coughlan NJA, Fu W, Guna M, Schneider BB, Le Blanc JCY, Campbell JL, Hopkins WS. Electronic spectroscopy of differential mobility-selected prototropic isomers of protonated para-aminobenzoic acid. Phys Chem Chem Phys 2021; 23:20607-20614. [PMID: 34505849 DOI: 10.1039/d1cp02120f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
para-Aminobenzoic acid (PABA) was electrosprayed from mixtures of protic and aprotic solvents, leading to formation of two prototropic isomers in the gas phase whose relative populations depended on the composition of the electrospray solvent. The two ion populations were separated in the gas phase using differential mobility spectrometry (DMS) within a nitrogen-only environment at atmospheric pressure. Under high-field conditions, the two prototropic isomers eluted with baseline signal separation with the N-protonated isomer having a more negative CV shift than the O-protonated isomer, in accord with previous DMS studies. The conditions most favorable for formation and separation of each tautomer were used to trap each prototropic isomer in a quadrupole ion trap for photodissociation action spectroscopy experiments. Spectral interrogation of each prototropic isomer in the UV region (3-6 eV) showed good agreement with previously recorded spectra, although a previously reported band (4.8-5.4 eV) was less intense for the O-protonated isomer in our measured spectrum. Without DMS selection, the measured spectra contained features corresponding to both protonated isomers even when solvent conditions were optimised for formation of a single isomer. Interconversion between protonated isomers within the ion trap was observed when protic ESI solvents were employed, leading to spectral cross contamination even with mobility selection. CCSD vertical excitation energies and vertical gradient (VG) Franck-Condon simulations are presented and reproduce the measured spectral features with near-quantitative agreement, providing supporting evidence for spectral assignments.
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Affiliation(s)
- Neville J A Coughlan
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada. .,Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Weiqiang Fu
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada. .,Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Mircea Guna
- SCIEX, Four Valley Drive, Concord, Ontario, L4K 4V8, Canada
| | | | | | - J Larry Campbell
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada. .,Bedrock Scientific Inc., Milton, Ontario, Canada.,WaterMine Innovation, Waterloo, Ontario, Canada
| | - W Scott Hopkins
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada. .,Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.,WaterMine Innovation, Waterloo, Ontario, Canada.,Centre for Eye and Vision Research, Hong Kong Science Park, New Territories, Hong Kong
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27
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Koopman J, Grimme S. From QCEIMS to QCxMS: A Tool to Routinely Calculate CID Mass Spectra Using Molecular Dynamics. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1735-1751. [PMID: 34080847 DOI: 10.1021/jasms.1c00098] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Mass spectrometry (MS) is a powerful tool in chemical research and substance identification. For the computational modeling of electron ionization MS, we have developed the quantum-chemical electron ionization mass spectra (QCEIMS) program. Here, we present an extension of QCEIMS to calculate collision-induced dissociation (CID) spectra. The more general applicability is accounted for by the new name QCxMS, where "x" refers to EI or CID. To this end, fragmentation and rearrangement reactions are computed "on-the-fly" in Born-Oppenheimer molecular dynamics (MD) simulations with the semiempirical GFN2-xTB Hamiltonian, which provides an efficient quantum mechanical description of all elements up to Z = 86 (Rn). Through the explicit modeling of multicollision processes between precursor ions and neutral gas atoms as well as temperature-induced decomposition reactions, QCxMS provides detailed insight into the collision kinetics and fragmentation pathways. In combination with the CREST program to determine the preferential protonation sites, QCxMS becomes the first standalone MD-based program that can predict mass spectra based solely on molecular structures as input. We demonstrate this for six organic molecules with masses ranging from 159 to 296 Da, for which QCxMS yields CID spectra in reasonable agreement with experiments.
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Affiliation(s)
- Jeroen Koopman
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany
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28
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McCullagh M, Goscinny S, Palmer M, Ujma J. Investigations into pesticide charge site isomers using conventional IM and cIM systems. Talanta 2021; 234:122604. [PMID: 34364418 DOI: 10.1016/j.talanta.2021.122604] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 06/05/2021] [Accepted: 06/09/2021] [Indexed: 11/28/2022]
Abstract
A growing number of pesticides are being used around the world necessitating strict regulatory policies to guarantee consumer safety. Liquid Chromatography - Mass Spectrometry (LC-MS) is a highly sensitive method for pesticide screening, which provides retention time, mass/charge ratios and the relative abundances of characteristic product ions. Variability in the latter necessitates relatively large tolerances (±30%, SANCO/12682/2019, current EU regulation). One cause of this variability may stem from the presence of different charge-site isomers (charge carrier being a proton, sodium cation, potassium cation and alike); each yielding a set of different product ions, of which the relative ratios are influenced by solution and ion source conditions. Consequently, varying relative abundances may be observed for analyte ions produced from calibration standards, chemical residues in food matrices and across different instruments. Ion Mobility Spectrometry (IMS) is a fast, gas phase separation technique which can resolve charge-site isomers based on differences in their collisional cross sections (CCSs). We previously used the IM device embedded in LC-IM-MS geometry to generate a pesticide CCS database and subsequently focussed upon identification of pesticides which form charge-site isomers. Latterly, we applied this approach to screen food commodities for pesticide residues. In some instances, isomer separation was clear, however sometimes broad, unresolved distributions were observed. Using a high-resolution cyclic IM device (cIM) we resolved and determined CCS values of species of indoxacarb, spinosad, fenpyroximate, epoxiconazole, metaflumizone and avermectin. Furthermore, utilising novel cIM functionalities (tandem-IM) we discovered that two spinosyn sodimers can interconvert in the gas phase.
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Affiliation(s)
| | - Séverine Goscinny
- Scientific Institute of Public Health, 14, Rue Juliette Wytsman, 1050, Brussels, Belgium
| | - Martin Palmer
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, UK
| | - Jakub Ujma
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, UK
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29
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Demireva M, Armentrout PB. Relative Energetics of the Gas Phase Protomers of p-Aminobenzoic Acid and the Effect of Protonation Site on Fragmentation. J Phys Chem A 2021; 125:2849-2865. [DOI: 10.1021/acs.jpca.0c11540] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Maria Demireva
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - P. B. Armentrout
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
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30
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Lermyte F, Theisen A, O'Connor PB. Solution Condition-Dependent Formation of Gas-Phase Protomers of Alpha-Synuclein in Electrospray Ionization. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:364-372. [PMID: 33237779 DOI: 10.1021/jasms.0c00373] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
One of the main characteristics of biomolecular ions in mass spectrometry is their net charge, and a range of approaches exist to either increase or decrease this quantity in the gas phase. In the context of small molecules, it is well known that, in addition to the charge state, the charge site also has a profound effect on an ion's gas-phase behavior; however, this effect has been far less explored for peptides and intact proteins. Methods exist to determine charge sites of protein ions, and others have observed that the interplay of electrostatic repulsion and inherent basicity leads to different sites gaining or losing a charge depending on the total net charge. Here, we report two distinct protonation site isomers ("protomers") of α-synuclein occurring at the same charge state. The protomers showed important differences in their gas-phase fragmentation behavior and were furthermore distinguishable by ion mobility spectrometry. One protomer was produced under standard electrospray conditions, while the other was observed after addition of 10% dimethyl sulfoxide to the protein solution. Charge sites for both protomers were determined using ultraviolet photodissociation.
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Affiliation(s)
- Frederik Lermyte
- Department of Chemistry, Technical University of Darmstadt, 64287 Darmstadt, Germany
- School of Engineering, University of Warwick, Coventry CV4 7AL, U.K
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Alina Theisen
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Peter B O'Connor
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
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31
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Valadbeigi Y, Ilbeigi V, Mirsharifi MS. Mechanism of atmospheric pressure chemical ionization of morphine, codeine, and thebaine in corona discharge-ion mobility spectrometry: Protonation, ammonium attachment, and carbocation formation. JOURNAL OF MASS SPECTROMETRY : JMS 2020; 55:e4586. [PMID: 32720743 DOI: 10.1002/jms.4586] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/30/2020] [Accepted: 06/05/2020] [Indexed: 06/11/2023]
Abstract
Atmospheric pressure chemical ionizations (APCIs) of morphine, codeine, and thebaine were studied in a corona discharge ion source using ion mobility spectrometry (IMS) at temperature range of 100°C-200°C. Density functional theory (DFT) at the B3LYP/6-311++G(d,p) and M062X/6-311++G(d,p) levels of theory were used to interpret the experimental data. It was found that in the presence of H3 O+ as reactant ion (RI), ionization of morphine and codeine proceeds via both the protonation and carbocation formation, whereas thebaine participates only in protonation. Carbocation formation (fragmentation) was diminished with decrease in the temperature. At lower temperatures, proton-bound dimers of the compounds were also formed. Ammonia was used as a dopant to produce NH4 + as an alternative RI. In the presence of NH4 + , proton transfer from ammonium ion to morphine, codeine, and thebaine was the dominant mechanism of ionization. However, small amount of ammonium attachment was also observed. The theoretical calculations showed that nitrogen atom of the molecules is the most favorable proton acceptor site while the oxygen atoms participate in ammonium attachment. Furthermore, formation of the carbocations is because of the water elimination from the protonated forms of morphine and codeine.
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Affiliation(s)
- Younes Valadbeigi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
| | - Vahideh Ilbeigi
- TOF Tech. Pars Company, Isfahan Science & Technology Town, Isfahan, Iran
| | - Maryam S Mirsharifi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
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32
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Thomas GT, Donnecke S, Paci I, McIndoe JS. Trichloro(Dinitrogen)Platinate(II). Chemistry 2020; 26:12359-12362. [PMID: 32598504 DOI: 10.1002/chem.202003057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Indexed: 01/07/2023]
Abstract
Zeise's salt, [PtCl3 (H2 C=CH2 )]- , is the oldest known organometallic complex, featuring ethylene strongly bound to a platinum salt. Many derivatives are known, but none involving dinitrogen, and indeed dinitrogen complexes are unknown for both platinum and palladium. Electrospray ionization mass spectrometry of K2 [PtCl4 ] solutions generate strong ions corresponding to [PtCl3 (N2 )]- , the identity of which was confirmed through ion-mobility spectrometry and MS/MS experiments that proved it to be distinct from its isobaric counterparts [PtCl3 (C2 H4 )]- and [PtCl3 (CO)]- . Computational analysis established a gas-phase platinum-dinitrogen bond strength of 116 kJ mol-1 , substantially weaker than the ethylene and carbon monoxide analogues but stronger than for polar solvents such as water, methanol and dimethylformamide, and strong enough that the calculated N-N bond length of 1.119 Å represents weakening to a degree typical of isolated dinitrogen complexes.
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Affiliation(s)
- Gilian T Thomas
- Department of Chemistry, University of Victoria, PO Box 1700 STN CSC, Victoria, British, Columbia, V8W 2Y2, Canada
| | - Sofia Donnecke
- Department of Chemistry, University of Victoria, PO Box 1700 STN CSC, Victoria, British, Columbia, V8W 2Y2, Canada
| | - Irina Paci
- Department of Chemistry, University of Victoria, PO Box 1700 STN CSC, Victoria, British, Columbia, V8W 2Y2, Canada
| | - J Scott McIndoe
- Department of Chemistry, University of Victoria, PO Box 1700 STN CSC, Victoria, British, Columbia, V8W 2Y2, Canada
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33
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May JC, Knochenmuss R, Fjeldsted JC, McLean JA. Resolution of Isomeric Mixtures in Ion Mobility Using a Combined Demultiplexing and Peak Deconvolution Technique. Anal Chem 2020; 92:9482-9492. [DOI: 10.1021/acs.analchem.9b05718] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Jody C. May
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | | | | | - John A. McLean
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
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34
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Soper-Hopper MT, Vandegrift J, Baker ES, Fernández FM. Metabolite collision cross section prediction without energy-minimized structures. Analyst 2020; 145:5414-5418. [PMID: 32583823 DOI: 10.1039/d0an00198h] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Matching experimental ion mobility-mass spectrometry data to computationally-generated collision cross section (CCS) values enables more confident metabolite identifications. Here, we show for the first time that accurately predicting CCS values with simple models for the largest library of metabolite cross sections is indeed possible, achieving a root mean square error of 7.0 Å2 (median error of ∼2%) using linear methods accesible to most researchers. A comparison on the performance of 2D vs. 3D molecular descriptors for the purposes of CCS prediction is also presented for the first time, enabling CCS prediction without a priori knowledge of the metabolite's energy-minimized structure.
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Affiliation(s)
- M T Soper-Hopper
- Northern Kentucky University, Department of Chemistry and Biochemistry, 1 Nunn Drive, Highland Heights, KY 41099, USA
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35
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Tsuge M, Chen YH, Lee YP. Infrared Spectra of Isomers of Protonated Aniline in Solid para-Hydrogen. J Phys Chem A 2020; 124:2253-2263. [DOI: 10.1021/acs.jpca.0c00241] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Masashi Tsuge
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
- Institute of Low Temperature Sciences, Hokkaido University, Sapporo 060-0819, Japan
| | - Yu-Hsuan Chen
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
- Center for Emergent Functional Matter Science, National Chiao Tung University, Hsinchu 30010, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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36
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Pracht P, Bohle F, Grimme S. Automated exploration of the low-energy chemical space with fast quantum chemical methods. Phys Chem Chem Phys 2020; 22:7169-7192. [PMID: 32073075 DOI: 10.1039/c9cp06869d] [Citation(s) in RCA: 890] [Impact Index Per Article: 222.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We propose and discuss an efficient scheme for the in silico sampling for parts of the molecular chemical space by semiempirical tight-binding methods combined with a meta-dynamics driven search algorithm. The focus of this work is set on the generation of proper thermodynamic ensembles at a quantum chemical level for conformers, but similar procedures for protonation states, tautomerism and non-covalent complex geometries are also discussed. The conformational ensembles consisting of all significantly populated minimum energy structures normally form the basis of further, mostly DFT computational work, such as the calculation of spectra or macroscopic properties. By using basic quantum chemical methods, electronic effects or possible bond breaking/formation are accounted for and a very reasonable initial energetic ranking of the candidate structures is obtained. Due to the huge computational speedup gained by the fast low-cost quantum chemical methods, overall short computation times even for systems with hundreds of atoms (typically drug-sized molecules) are achieved. Furthermore, specialized applications, such as sampling with implicit solvation models or constrained conformational sampling for transition-states, metal-, surface-, or noncovalently bound complexes are discussed, opening many possible applications in modern computational chemistry and drug discovery. The procedures have been implemented in a freely available computer code called CREST, that makes use of the fast and reliable GFNn-xTB methods.
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Affiliation(s)
- Philipp Pracht
- Mulliken Center for Theoretical Chemistry, Universität Bonn, Beringstr. 4, 53115 Bonn, Germany.
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37
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Chandran J, Zheng Z, Thomas VI, Rajalakshmi C, Attygalle AB. LC-MS analysis of p-aminosalicylic acid under electrospray ionization conditions manifests a profound solvent effect. Analyst 2020; 145:5333-5344. [DOI: 10.1039/d0an00680g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Under identical mass spectrometric conditions, chromatographic peak intensities of p-aminosalicylic acid recorded by LC-MS, using methanol as the mobile phase are drastically different from those acquired using is it acetonitrile as the eluent.
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Affiliation(s)
- Jisha Chandran
- Inter University Instrumentation Centre (IUIC)
- School of Environmental Sciences
- Mahatma Gandhi University
- Kottayam
- 686560 India
| | - Zhaoyu Zheng
- Center for Mass Spectrometry
- Department of Chemistry and Chemical Biology
- Stevens Institute of Technology
- Hoboken
- USA
| | | | | | - Athula B. Attygalle
- Center for Mass Spectrometry
- Department of Chemistry and Chemical Biology
- Stevens Institute of Technology
- Hoboken
- USA
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38
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Kune C, Delvaux C, Haler JRN, Quinton L, Eppe G, De Pauw E, Far J. A Mechanistic Study of Protonated Aniline to Protonated Phenol Substitution Considering Tautomerization by Ion Mobility Mass Spectrometry and Tandem Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2238-2249. [PMID: 31520338 DOI: 10.1007/s13361-019-02321-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 08/01/2019] [Accepted: 08/11/2019] [Indexed: 06/10/2023]
Abstract
We report the use of ion mobility mass spectrometry (IMMS) and energy-resolved collisional activation to investigate gas-phase reactions of protonated aniline and protonated phenol. Protonated aniline prototropic tautomerization and nucleophilic substitution (SN1) to produce phenol with traces of water in the IMMS cell are reported. Tautomerization of protonated phenol and its ability to form protonated aniline in presence of ammonia in the gas phase are also observed. These results are supported by energy landscapes obtained from computational chemistry. These structure modifications in the IMMS cell affected the measured collision cross section (CCS). A thorough understanding of the gas-phase reactions occurring in IMMS appears mandatory before using the experimental CCS as a robust descriptor which is stated by the recent literature.
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Affiliation(s)
- Christopher Kune
- MOLSYS, Mass Spectrometry Laboratory, University of Liège, Quartier Agora, Allée du Six Aout 11, B-4000, Liège, Belgium.
| | - Cédric Delvaux
- MOLSYS, Mass Spectrometry Laboratory, University of Liège, Quartier Agora, Allée du Six Aout 11, B-4000, Liège, Belgium
| | - Jean R N Haler
- MOLSYS, Mass Spectrometry Laboratory, University of Liège, Quartier Agora, Allée du Six Aout 11, B-4000, Liège, Belgium
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL, 33199, USA
| | - Loïc Quinton
- MOLSYS, Mass Spectrometry Laboratory, University of Liège, Quartier Agora, Allée du Six Aout 11, B-4000, Liège, Belgium
| | - Gauthier Eppe
- MOLSYS, Mass Spectrometry Laboratory, University of Liège, Quartier Agora, Allée du Six Aout 11, B-4000, Liège, Belgium
| | - Edwin De Pauw
- MOLSYS, Mass Spectrometry Laboratory, University of Liège, Quartier Agora, Allée du Six Aout 11, B-4000, Liège, Belgium
| | - Johann Far
- MOLSYS, Mass Spectrometry Laboratory, University of Liège, Quartier Agora, Allée du Six Aout 11, B-4000, Liège, Belgium
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39
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Ross DH, Seguin RP, Xu L. Characterization of the Impact of Drug Metabolism on the Gas-Phase Structures of Drugs Using Ion Mobility-Mass Spectrometry. Anal Chem 2019; 91:14498-14507. [PMID: 31613088 DOI: 10.1021/acs.analchem.9b03292] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Conventional strategies for drug metabolite identification employ a combination of liquid chromatography-mass spectrometry (LC-MS), which offers higher throughput but provides limited structural information, and nuclear magnetic resonance spectroscopy, which can achieves the most definitive identification but lacks throughput. Ion mobility-mass spectrometry (IM-MS) is a rapid, two-dimensional analysis that separates ions on the basis of their gas-phase size and shape (reflected by collision cross section, CCS) and their mass-to-charge (m/z) ratios. The rapid nature of IM separation combined with the structural information provided by CCS make IM-MS a promising technique for obtaining more structural information on drug metabolites without sacrificing analytical throughput. Here, we present an in vitro biosynthesis coupled with IM-MS strategy for rapid generation and analysis of drug metabolites. Drug metabolites were generated in vitro using pooled subcellular fractions derived from human liver and analyzed using a rapid flow injection-IM-MS method. We measured CCS values for 19 parent drugs and their 37 metabolites generated in vitro (78 values in total), representing a wide variety of metabolic modifications. Post-IM fragmentation and computational modeling were used to support metabolite identifications and explore the structural characteristics driving behaviors observed in IM separation. Overall, we found the effects of metabolic modifications on the gas-phase structures of the metabolites to be highly dependent upon the structural characteristics of the parent compounds and the specific position of the modification. This in vitro biosynthesis coupled with rapid IM-MS analysis workflow represents a promising platform for rapid and high-confidence identification of drug metabolites, applicable at a large scale.
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Affiliation(s)
- Dylan H Ross
- Department of Medicinal Chemistry , University of Washington , Seattle , Washington 98195 , United States
| | - Ryan P Seguin
- Department of Medicinal Chemistry , University of Washington , Seattle , Washington 98195 , United States
| | - Libin Xu
- Department of Medicinal Chemistry , University of Washington , Seattle , Washington 98195 , United States
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40
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McCullagh M, Giles K, Richardson K, Stead S, Palmer M. Investigations into the performance of travelling wave enabled conventional and cyclic ion mobility systems to characterise protomers of fluoroquinolone antibiotic residues. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33 Suppl 2:11-21. [PMID: 30549457 DOI: 10.1002/rcm.8371] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/08/2018] [Accepted: 12/10/2018] [Indexed: 05/26/2023]
Abstract
RATIONALE Fluoroquinolones (FLQs) have been shown to form protomers with distinctive fragment profiles. Experimental parameters affect protomer formation, impacting observed conventional tandem mass spectrometric (MS/MS) dissociation and multiple reaction monitoring (MRM) transition reproducibility. Collision cross section (CCS) measurement can provide an additional identification metric and improved ion mobility (IM) separation strategies could provide further understanding of fluctuations in fragmentation when using electrospray ionisation (ESI). METHODS Porcine muscle tissue was fortified with nine fluoroquinolone antibiotics. Extracts were cleaned using QuEChERS dispersive extraction. Separation was achieved via ultra-high-performance liquid chromatography (UHPLC) and analysis performed using positive ion ESI coupled with linear T-wave IM (N2 and CO2 drift gas) and cyclic IM-MS (calibrated to perform accurate mass and CCS measurement). RESULTS IM-resolved protomeric species have been observed for nine FLQs (uniquely three for danofloxacin). Long-term reproducibility and cross-platform T-wave/cIM studies have demonstrated CCS metric errors <1.5% when compared with a FLQ protomer reference CCS library. When comparing FLQ protomer separation using a standard, linear T-wave IM separator (N2 /CO2 ) and using a high-resolution cyclic T-wave device (N2 ), protomer peak-to-peak resolution ranged between Rs = 1 to Rs = 6 for the IM strategies utilised. CONCLUSIONS CCS is a reliable cross platform metric; specific FLQ CCS identification fingerprints have been produced, illustrating the potential to compliment MS/MS specificity or provide an alternative identification metric. Using cIM there is opportunity to correlate the erratic nature of protomer formation with the analytical conditions used and to gain further understanding of ionisation/dissociation mechanisms taking place during routine analyses.
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Affiliation(s)
- Michael McCullagh
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, SK9 4AX, UK
| | - Kevin Giles
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, SK9 4AX, UK
| | - Keith Richardson
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, SK9 4AX, UK
| | - Sara Stead
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, SK9 4AX, UK
| | - Martin Palmer
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, SK9 4AX, UK
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41
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Stark TD, Ranner J, Stiglbauer B, Weiss P, Stark S, Balemba OB, Hofmann T. Construction and Application of a Database for a Five-Dimensional Identification of Natural Compounds in Garcinia Species by Means of UPLC-ESI-TWIMS-TOF-MS: Introducing Gas Phase Polyphenol Conformer Drift Time Distribution Intensity Ratios. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:975-985. [PMID: 30576604 DOI: 10.1021/acs.jafc.8b06157] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Thirty-four reference compounds from G. buchananii were analyzed by means of UPLC-ESI-IMS-TOF-MS to build a database consisting of retention time, accurate m/ z of precursors and fragment ions, and rotationally averaged collision cross-sectional area (CCS). The CCS value of six selected compounds analyzed in bark extract in different concentrations and solvent systems showed excellent intra- and interday precision (RSD ≤ 0.9%). The established database was applied on different organs of G. buchananii as well as G. kola, G. mangostana, and G. cambogia enabling a fast and reliable identification of these natural bioactives. For several compounds, more than one drift time species could be highlighted, which we propose to be hydrogen bond stabilized rotational isomers transferred from solution to gas phase. We used all CCS values of one compound, and we propose to add also the intensity ratio of the conformers as a new and additional characteristic compound parameter in compound identification/screening/database applications to reduce dereplication and false positives and to strengthen the identification.
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Affiliation(s)
- Timo D Stark
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik , Technische Universität München , Lise-Meitner-Str. 34 , 85354 Freising , Germany
| | - Josef Ranner
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik , Technische Universität München , Lise-Meitner-Str. 34 , 85354 Freising , Germany
| | - Benedikt Stiglbauer
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik , Technische Universität München , Lise-Meitner-Str. 34 , 85354 Freising , Germany
| | - Patrick Weiss
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik , Technische Universität München , Lise-Meitner-Str. 34 , 85354 Freising , Germany
| | - Sofie Stark
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik , Technische Universität München , Lise-Meitner-Str. 34 , 85354 Freising , Germany
| | - Onesmo B Balemba
- Department of Biological Sciences , University of Idaho , Moscow , Idaho 83844 , United States
| | - Thomas Hofmann
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik , Technische Universität München , Lise-Meitner-Str. 34 , 85354 Freising , Germany
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42
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Marlton SJP, McKinnon BI, Ucur B, Maccarone AT, Donald WA, Blanksby SJ, Trevitt AJ. Selecting and identifying gas-phase protonation isomers of nicotineH+ using combined laser, ion mobility and mass spectrometry techniques. Faraday Discuss 2019; 217:453-475. [DOI: 10.1039/c8fd00212f] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protonation isomers of gas-phase nicotineH+ are separated and assigned using a combination of FAIMS and UV photodissociation action spectroscopy.
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Affiliation(s)
| | | | - Boris Ucur
- School of Chemistry
- University of Wollongong
- Wollongong
- Australia
| | | | | | - Stephen J. Blanksby
- Central Analytical Research Facility
- Institute for Future Environments
- Queensland University of Technology
- Brisbane
- Australia
| | - Adam J. Trevitt
- School of Chemistry
- University of Wollongong
- Wollongong
- Australia
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43
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Crescentini TM, Stow SM, Forsythe JG, May JC, McLean JA, Hercules DM. Structural Characterization of Methylenedianiline Regioisomers by Ion Mobility-Mass Spectrometry and Tandem Mass Spectrometry. 4. 3-Ring and 4-Ring Isomers. Anal Chem 2018; 90:14453-14461. [PMID: 30479133 DOI: 10.1021/acs.analchem.8b04103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) is used to characterize methylenedianiline (MDA) 3-ring and 4-ring species. Building on our previous MALDI-MS 2-ring MDA isomer study, here we compare 3-ring and 4-ring electrospray ionization (ESI) and MALDI results. In ESI, 3-ring and 4-ring MDAs each form a single [M + H]+ parent ion. However, in MALDI, each MDA multimer forms three unique precursor ions: [M + H]+, [M•]+, and [M - H]+. In this study, 3-ring and 4-ring MDA precursors are characterized to identify the unique fragment ions formed and their respective fragmentation pathways. In addition to the three possible precursors, the 3-ring and 4-ring species are higher-order oligomer precursors in polyurethane (PUR) production and thus provide additional insight into the polymeric behavior of these PUR hard block precursors. The combination of ion mobility-mass spectrometry (IM - MS) and tandem mass spectrometry (MS/MS) allow the structural characterization of these larger MDA multimers.
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Affiliation(s)
- Tiffany M Crescentini
- Department of Chemistry , Vanderbilt University , Nashville , Tennessee 37235 , United States
| | - Sarah M Stow
- Department of Chemistry , Vanderbilt University , Nashville , Tennessee 37235 , United States
| | - Jay G Forsythe
- Department of Chemistry , Vanderbilt University , Nashville , Tennessee 37235 , United States.,Department of Chemistry and Biochemistry , College of Charleston , Charleston , South Carolina 29424 , United States
| | - Jody C May
- Department of Chemistry , Vanderbilt University , Nashville , Tennessee 37235 , United States
| | - John A McLean
- Department of Chemistry , Vanderbilt University , Nashville , Tennessee 37235 , United States
| | - David M Hercules
- Department of Chemistry , Vanderbilt University , Nashville , Tennessee 37235 , United States
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44
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Erabelli R, Xu S, Attygalle AB. Gas-phase protomers of p-(dimethylamino)chalcone investigated by travelling-wave ion mobility mass spectrometry (TWIMS). JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:954-962. [PMID: 29989269 DOI: 10.1002/jms.4265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 06/24/2018] [Accepted: 06/27/2018] [Indexed: 06/08/2023]
Abstract
Results from ion-mobility (IM) separation experiments demonstrate that O- and N-protomers of p-(dimethylamino)chalcone (p-DMAC) can coexist in the gas phase. The relative populations of the two protomers strongly depend on the ion-generating settings and the conditions the precursor ions experience from the point of their gas-phase inception to the time of their detection. Under relatively dry source conditions, the ratio of the gas-phase protomers generated under helium-plasma ionization (HePI) conditions is biased towards the thermodynamically favored O-protomer. However, when the humidity of the enclosed ion source was increased, the IM arrival-time distribution profile of the mass-selected protonated precursor of p-DMAC changed rapidly to one dominated by the N-protomer. Under spray-ionization conditions, the formation of the thermodynamically less favored protomer has been generally attributed to a phenomenon called kinetic trapping. Herein, we demonstrate that the population of thermodynamically less favored N-protomer can be dramatically increased simply by introducing water vapor to the HePI ion source.
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Affiliation(s)
- Ramu Erabelli
- Center for Mass Spectrometry, Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey
| | - Sihang Xu
- Center for Mass Spectrometry, Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey
| | - Athula B Attygalle
- Center for Mass Spectrometry, Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey
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45
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Hinnenkamp V, Klein J, Meckelmann SW, Balsaa P, Schmidt TC, Schmitz OJ. Comparison of CCS Values Determined by Traveling Wave Ion Mobility Mass Spectrometry and Drift Tube Ion Mobility Mass Spectrometry. Anal Chem 2018; 90:12042-12050. [DOI: 10.1021/acs.analchem.8b02711] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Vanessa Hinnenkamp
- IWW Water Centre, Moritzstraße 26, 45476 Muelheim an der Ruhr, Germany
- Instrumental Analytical Chemistry and Centre for Water and Environmental Research, Universitaetsstrasse 5, 45141 Essen, Germany
| | | | | | - Peter Balsaa
- IWW Water Centre, Moritzstraße 26, 45476 Muelheim an der Ruhr, Germany
| | - Torsten C. Schmidt
- IWW Water Centre, Moritzstraße 26, 45476 Muelheim an der Ruhr, Germany
- Instrumental Analytical Chemistry and Centre for Water and Environmental Research, Universitaetsstrasse 5, 45141 Essen, Germany
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46
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Kune C, Haler JRN, Far J, De Pauw E. Effectiveness and Limitations of Computational Chemistry and Mass Spectrometry in the Rational Design of Target-specific Shift Reagents for Ion Mobility Spectrometry. Chemphyschem 2018; 19:2921-2930. [DOI: 10.1002/cphc.201800555] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Indexed: 01/14/2023]
Affiliation(s)
- Christopher Kune
- Mass Spectrometry Laboratory; University of Liège; Quartier Agora; Allée du Six Aout 11, B- 4000 Liège Belgium
| | - Jean R. N. Haler
- Mass Spectrometry Laboratory; University of Liège; Quartier Agora; Allée du Six Aout 11, B- 4000 Liège Belgium
| | - Johann Far
- Mass Spectrometry Laboratory; University of Liège; Quartier Agora; Allée du Six Aout 11, B- 4000 Liège Belgium
| | - Edwin De Pauw
- Mass Spectrometry Laboratory; University of Liège; Quartier Agora; Allée du Six Aout 11, B- 4000 Liège Belgium
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47
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Mehmood A, Janesko BG. Predicting ion mobility collision cross sections directly from standard quantum chemistry software. JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:432-434. [PMID: 29505693 DOI: 10.1002/jms.4078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 02/23/2018] [Accepted: 02/26/2018] [Indexed: 06/08/2023]
Abstract
A method is proposed to predict ions' collision cross-sectional area from properties that are already evaluated in standard quantum chemistry software. Computed molecular isodensity surface areas recover the predictions of existing projection approximations. Computed solvent cavity areas give comparable accuracy. This provides a simplified workflow for assigning ion-mobility mass spectra.
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Affiliation(s)
- Arshad Mehmood
- Department of Chemistry and Biochemistry, Texas Christian University, Fort Worth, TX, 76129, USA
| | - Benjamin G Janesko
- Department of Chemistry and Biochemistry, Texas Christian University, Fort Worth, TX, 76129, USA
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48
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Xia H, Attygalle AB. Transformation of the gas-phase favored O-protomer of p-aminobenzoic acid to its unfavored N-protomer by ion activation in the presence of water vapor: An ion-mobility mass spectrometry study. JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:353-360. [PMID: 29377420 DOI: 10.1002/jms.4066] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/12/2018] [Accepted: 01/18/2018] [Indexed: 05/26/2023]
Abstract
An ion-mobility mass spectrometry study showed that the preferred O-protonated form of p-aminobenzoic in the gas phase can be converted to the thermodynamically less favored N-protomer by in-source collision-induced ion activation during the ion transfer process from the atmospheric region to the first vacuum region if the humidity is high in the ion source. Upon the addition of water vapor to the nitrogen gas used to promote the solid analyte to the gas phase under helium-plasma ionization conditions, the intensity of the ion-mobility arrival-time peak for the N-protomer increased dramatically. Evidently, the ion-activation process in the first vacuum region is able to provide the energy required to surmount the barrier to isomerize the O-protomer to the more energetic N-protomer. The transfer of the proton attached to the carbonyl oxygen atom of the O-protomer to the amino group takes place by a water-bridge mechanism. Apparently, the postionization transformations that take place during the transmission of ions from the atmospheric-pressure ion source to the detector, via different physical compartments of low to high vacuum, play an eminent role in determining the population ratios eventually manifested at the detector.
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Affiliation(s)
- Hanxue Xia
- Center for Mass Spectrometry, Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey, 07030, USA
| | - Athula B Attygalle
- Center for Mass Spectrometry, Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey, 07030, USA
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49
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Bauer A, Kuballa J, Rohn S, Jantzen E, Luetjohann J. Evaluation and validation of an ion mobility quadrupole time-of-flight mass spectrometry pesticide screening approach. J Sep Sci 2018; 41:2178-2187. [DOI: 10.1002/jssc.201701059] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 01/03/2018] [Accepted: 02/06/2018] [Indexed: 12/30/2022]
Affiliation(s)
- Anna Bauer
- Research and Development Department; GALAB Laboratories GmbH; Hamburg Germany
| | - Juergen Kuballa
- Research and Development Department; GALAB Laboratories GmbH; Hamburg Germany
| | - Sascha Rohn
- Institute of Food Chemistry; Hamburg School of Food Science; University of Hamburg; Hamburg Germany
| | - Eckard Jantzen
- Research and Development Department; GALAB Laboratories GmbH; Hamburg Germany
| | - Jens Luetjohann
- Research and Development Department; GALAB Laboratories GmbH; Hamburg Germany
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50
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Dias HJ, Bento MVB, da Silva ÉH, Saturnino-Júnior A, de Oliveira MF, Vessecchi R, Parreira RLT, Crotti AEM. Gas-phase fragmentation reactions of protonated cocaine: New details to an old story. JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:203-213. [PMID: 29247586 DOI: 10.1002/jms.4053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/22/2017] [Accepted: 12/05/2017] [Indexed: 06/07/2023]
Affiliation(s)
- Herbert J Dias
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, Franca, SP, Brazil
| | - Mariana V B Bento
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, Franca, SP, Brazil
| | | | - Andrade Saturnino-Júnior
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, Franca, SP, Brazil
| | - Marcelo F de Oliveira
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Ricardo Vessecchi
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Renato L T Parreira
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, Franca, SP, Brazil
| | - Antônio E M Crotti
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
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