1
|
Zheng M, Zhang X, Cheng Y, Sun L, Zhang X. Hydroxyl transfer versus cyclization reaction in the gas phase: Sequential loss of NH 3 and CH 2CO from protonated phenylalanine derivatives. Front Chem 2023; 10:1094329. [PMID: 36700082 PMCID: PMC9868239 DOI: 10.3389/fchem.2022.1094329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 12/23/2022] [Indexed: 01/10/2023] Open
Abstract
Collisional activation of protonated phenylalanine derivatives deamination products leads to hydroxyl skeletal rearrangement versus cyclization reaction, and to form hydroxylbenzyl cation via elimination of CH2CO. To better clarify this unusual fragmentation reaction, accurate mass measurements experiments, native isotope experiments, multiple-stage mass spectrometry experiments, different substituents experiments, and density functional theory (DFT) calculations were carried out to investigate the dissociation mechanistic pathways of protonated phenylalanine derivatives deamination products. In route 1, a three-membered ring-opening reaction and a 1,3-hydroxyl transfer (from the carbonyl carbon atom to the interposition carbon atom of carbonyl) occurs to form 3-hydroxy-1-oxo-3-phenylpropan-1-ylium, followed by dissociation to lose CH2CO to give hydroxy (phenyl)methylium. In route 2, a successive cyclization rearrangement reaction and proton transfer occur to form a 2-hydroxylphenylpropionyl cation or protonated 2-hydroxy-4H-benzopyran, followed by dissociation to lose CH2CO or CH≡COH to give 2-hydroxylbenzyl cation. In route 3, a successive hydroxyl transfer (from the carbonyl carbon atom to the ortho carbon atom on benzene) and two stepwise proton transfer (1,2-proton transfer to the ipso-carbon atom of the phenyl ring followed by 1,3-proton transfer to the ortho carbon atom of carbonyl) occurs to form a 2-hydroxylphenylpropionyl cation, which subsequently dissociates to form 2-hydroxylbenzyl cation by elimination of CH2CO. DFT calculations suggested that route 1 was more favorable than route 2 and route 3 from a thermodynamic point of view.
Collapse
|
2
|
Zhang X, Chen H, Ji Y, Jiang K, Chen H. Sulfur Transfer Versus Phenyl Ring Transfer in the Gas Phase: Sequential Loss of CH 3OH and CH 3O-P=O from Protonated Phosphorothioates. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:459-467. [PMID: 30569428 DOI: 10.1007/s13361-018-2098-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 10/22/2018] [Accepted: 10/24/2018] [Indexed: 06/09/2023]
Abstract
Collisional activation fragmentation of protonated phosphorothioates leads to skeletal rearrangement and formation of aryl sulfenylium cation (R-PhS+) via successive eliminations of CH3OH and CH3O-P=O. To better understand this unusual fragmentation reaction, isotope-labeling experiments and density functional theory (DFT) calculations were carried out to investigate two mechanistic pathways. In route 1, a direct intramolecular transfer of the R-phenyl group occurs from the oxygen atom to the sulfur atom on thiophosphoryl to form methoxyl S-(3-methyl-4-methylsulfanyl-phenyl) phosphonium thiolate (a4), which subsequently dissociates to form the m/z 169 cation. In route 2, the sulfur atom of the thiophosphoryl group undergoes two stepwise transfer (1,4-migration to the ortho-carbon atom of the phenyl ring followed by 1,2-migration to the ipso-carbon atom) to form an intermediate isomer, which undergoes the subsequent dissociation to form the m/z 169 cation. DFT calculations suggested that route 2 was more favorable than route 1 from the point view of kinetics. Graphical Abstract.
Collapse
Affiliation(s)
- Xiaoping Zhang
- Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang, 330013, People's Republic of China
| | - Honghan Chen
- Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang, 330013, People's Republic of China
| | - Yin Ji
- Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang, 330013, People's Republic of China
| | - Kezhi Jiang
- Key Laboratory of Organosilicon Chemistry and Material Technology, Hangzhou Normal University, Hangzhou, 311121, China.
| | - Huanwen Chen
- Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang, 330013, People's Republic of China.
| |
Collapse
|
3
|
Frański R, Gierczyk B, Zalas M, Jankowski W, Hoffmann M. Methyl group transfer upon gas phase decomposition of protonated methyl benzoate and similar compounds. JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:379-384. [PMID: 29441643 DOI: 10.1002/jms.4069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 01/05/2018] [Accepted: 02/02/2018] [Indexed: 06/08/2023]
Abstract
Gas phase decompositions of protonated methyl benzoate and its conjugates have been studied by using electrospray ionization-collision induced dissociation-tandem mass spectrometry. Loss of CO2 molecule, thus transfer of methyl group, has been observed. In order to better understand this process, the theoretical calculations have been performed. For methyl benzoate conjugates, it has been found that position of substituent affects the loss of CO2 molecule, not the electron donor/withdrawing properties of the substituent. Therefore, electrospray ionization-mass spectrometry in positive ion mode may be useful for differentiation of isomers of methyl benzoate conjugates.
Collapse
Affiliation(s)
- Rafał Frański
- Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614, Poznań, Poland
| | - Błażej Gierczyk
- Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614, Poznań, Poland
| | - Maciej Zalas
- Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614, Poznań, Poland
| | - Wojciech Jankowski
- Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614, Poznań, Poland
| | - Marcin Hoffmann
- Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614, Poznań, Poland
| |
Collapse
|
4
|
Nikolić D, Macias C, Lankin DC, van Breemen RB. Collision-induced dissociation of phenethylamides: role of ion-neutral complexes. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:1385-1395. [PMID: 28558170 PMCID: PMC5555735 DOI: 10.1002/rcm.7915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 04/21/2017] [Accepted: 05/25/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE Phenethylamides are a large group of naturally occurring molecules found both in the plant and animal kingdoms. In addition, they are used as intermediates for the synthesis of pharmaceutically important dihydro- and tetrahydroisoquinolines. To enable efficient characterization of this class of molecules, a detailed mass spectrometric fragmentation study of a broad series of analogs was carried out. METHODS The test compounds were synthesized using standard methods for amide bond formation. Low-energy high-resolution tandem mass spectra were acquired on a hybrid quadrupole/time-of-flight mass spectrometer using positive ion electrospray ionization. RESULTS A total of 26 analogs were investigated in the study. Fragmentation of phenethylamides was found to proceed via intermediate ion-neutral complexes. The complexes can break down via multiple pathways including dissociation, proton transfer, Friedel-Crafts acylation, and single electron transfer. The relative contribution of each of these pathways strongly depends on the structure of the coupling amine and acid. CONCLUSIONS A general scheme for the fragmentation of phenethylamides was developed. This study further extends the knowledge base of the ion-neutral complex by discovering Friedel-Crafts acylation as a novel reaction. The strong influence of minor structural modifications on the fragmentation patterns highlights the importance of testing many analogs in order to fully predict a fragmentation pattern of a particular class of molecules.
Collapse
Affiliation(s)
- Dejan Nikolić
- Corresponding Author: Dejan Nikolić, Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 833 S. Wood St., Chicago, IL 60612-7231, Telephone (312) 413-5867, FAX (312) 996-7107,
| | | | | | | |
Collapse
|
5
|
Quantification of lactate from various metabolic pathways and quantification issues of lactate isotopologues and isotopmers. Sci Rep 2017; 7:8489. [PMID: 28814730 PMCID: PMC5559627 DOI: 10.1038/s41598-017-08277-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 07/06/2017] [Indexed: 12/31/2022] Open
Abstract
13C-labeled glucose combined with chromatography and mass spectrometry enables us to decipher the percentage of lactate generated from various metabolic pathways. We showed that lactate derived from glycolysis, pentose phosphate pathway, Krebs cycle, and other sources accounted for 82-90%, 6.0-11%, 0.67-1.8% and 1.5-7.9%, respectively, depending on different types of cells. When using glucose isotopomers ([1-13C]-, [3-13C]-, [4-13C]-, and [6-13C]glucose) or isotopologues ([1,2-13C2]- and [1,2,3-13C3]glucose) for tracing, the ratio of lactate derived from glucose carbon 1, 2, 3 over 4, 5, 6 via glycolysis varied significantly, ranging from 1.6 (traced with [1,2-13C2]glucose) to 0.85 (traced with [6-13C]glucose), but the theoretical ratio should be 1. The odd results might be caused by intramolecular 13C, which may significantly affect lactate fragmentation under tandem mass spectrometry condition, leading to erroneous quantification. Indeed, the fragmentation efficiency of [U-13C]lactate, [2,3-13C]lactate, and [3-13C]lactate were 1.4, 1.5 and 1.2 folds higher than lactate, respectively, but [1-13C]lactate was similar to lactate, suggesting that carbon-13 at different positions could differentially influence lactate fragmentation. This observed phenomenon was inconsistent with the data based on theoretical calculation, according to which activation energies for all lactate isotopomers and isotopologues are nearly identical. The inconsistency suggested a need for further investigation. Our study suggests that calibration is required for quantifying metabolite isotopolugues and isotopomers.
Collapse
|
6
|
Zu C, Mukhopadhyay S, Hanley PS, Xia S, Bell BM, Grigg D, Gilbert JR, O'Brien JP. Fragmentation of Protonated N-(3-Aminophenyl)Benzamide and Its Derivatives in Gas Phase. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:917-926. [PMID: 26988371 DOI: 10.1007/s13361-016-1342-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 01/11/2016] [Accepted: 01/13/2016] [Indexed: 06/05/2023]
Abstract
An ion of m/z 110.06036 (ion formula [C6H8NO](+); error: 0.32 mDa) was observed in the collision induced dissociation tandem mass spectrometry experiments of protonated N-(3-aminophenyl)benzamide, which is a rearrangement product ion purportedly through nitrogen-oxygen (N-O) exchange. The N-O exchange rearrangement was confirmed by the MS/MS spectrum of protonated N-(3-aminophenyl)-O (18) -benzamide, where the rearranged ion, [C6H8NO (18) ](+) of m/z 112 was available because of the presence of O (18) . Theoretical calculations using Density Functional Theory (DFT) at B3LYP/6-31 g(d) level suggest that an ion-neutral complex containing a water molecule and a nitrilium ion was formed via a transition state (TS-1), followed by the water molecule migrating to the anilide ring, eventually leading to the formation of the rearranged ion of m/z 110. The rearrangement can be generalized to other protonated amide compounds with electron-donating groups at the meta position, such as, -OH, -CH3, -OCH3, -NH(CH3)2, -NH-Ph, and -NHCOCH3, all of which show the corresponding rearranged ions in MS/MS spectra. However, the protonated amide compounds containing electron-withdrawing groups, including -Cl, -Br, -CN, -NO2, and -CF3, at the meta position did not display this type of rearrangement during dissociation. Additionally, effects of various acyl groups on the rearrangement were investigated. It was found that the rearrangement can be enhanced by substitution on the ring of the benzoyl with electron-withdrawing groups.
Collapse
Affiliation(s)
- Chengli Zu
- Analytical Technology Center, The Dow Chemical Company, Midland, MI, 48667, USA.
| | | | - Patrick S Hanley
- Process Science, The Dow Chemical Company, Midland, MI, 48674, USA
| | - Shijing Xia
- Dow Electronic Materials, The Dow Chemical Company, Newark, DE, 19713, USA
| | - Bruce M Bell
- Analytical Sciences, The Dow Chemical Company, Midland, MI, 48667, USA
| | - David Grigg
- Organic Polymers and Organometallics, The Dow Chemical Company, Midland, MI, 48674, USA
| | - Jeffrey R Gilbert
- Dow AgroSciences, The Dow Chemical Company, Indianapolis, IN, 46268, USA
| | - John P O'Brien
- Analytical Sciences, The Dow Chemical Company, Midland, MI, 48667, USA
| |
Collapse
|
7
|
Wang S, Dong C, Yu L, Guo C, Jiang K. Dissociation of protonated N-(3-phenyl-2H-chromen-2-ylidene)-benzenesulfonamide in the gas phase: cyclization via sulfonyl cation transfer. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:95-100. [PMID: 26661975 DOI: 10.1002/rcm.7420] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 09/23/2015] [Accepted: 10/05/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE In the tandem mass spectrometry of protonated N-(3-phenyl-2H-chromen-2-ylidene)benzenesulfonamides, the precursor ions have been observed to undergo gas-phase dissociation via two competing channels: (a) the predominant channel involves migration of the sulfonyl cation to the phenyl C atom and the subsequent loss of benzenesulfinic acid along with cyclization reaction, and (b) the minor one involves dissociation of the precursor ion to give an ion/neutral complex of [sulfonyl cation/imine], followed by decomposition to afford sulfonyl cation or the INC-mediated electron transfer to give an imine radical cation. METHODS The proposed reaction channels have been supported by theoretical calculations and D-labeling experiments. RESULTS The gas-phase cyclization reaction originating from the N- to C-sulfonyl cation transfer has been first reported to the best of our knowledge. CONCLUSIONS For the substituted sulfonamides, the presence of electron-donating groups (R(2) -) at the C-ring effectively facilitates the reaction channel of cyclization reaction, whereas that of electron-withdrawing groups inhibits this pathway.
Collapse
Affiliation(s)
- Shanshan Wang
- Key Laboratory of Organosilicon Chemistry and Material Technology, Hangzhou Normal University, Hangzhou, 311121, China
| | - Cheng Dong
- Key Laboratory of Organosilicon Chemistry and Material Technology, Hangzhou Normal University, Hangzhou, 311121, China
| | - Lian Yu
- Key Laboratory of Organosilicon Chemistry and Material Technology, Hangzhou Normal University, Hangzhou, 311121, China
| | - Cheng Guo
- Cancer Institute, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
| | - Kezhi Jiang
- Key Laboratory of Organosilicon Chemistry and Material Technology, Hangzhou Normal University, Hangzhou, 311121, China
| |
Collapse
|
8
|
Chai Y, Xiong X, Yue L, Jiang Y, Pan Y, Fang X. Intramolecular Halogen Transfer via Halonium Ion Intermediates in the Gas Phase. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:161-167. [PMID: 26383734 DOI: 10.1007/s13361-015-1261-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 08/31/2015] [Accepted: 09/01/2015] [Indexed: 06/05/2023]
Abstract
The fragmentation of halogen-substituted protonated amines and quaternary ammonium ions (R(1)R(2)R(3)N(+)CH2(CH2)nX, where X = F, Cl, Br, I, n = 1, 2, 3, 4) was studied by electrospray ionization tandem mass spectrometry. A characteristic fragment ion (R(1)R(2)R(3)N(+)X) resulting from halogen transfer was observed in collision-induced dissociation. A new mechanism for the intramolecular halogen transfer was proposed that involves a reactive intermediate, [amine/halonium ion]. A potential energy surface scan using DFT calculation for CH2-N bond cleavage process of protonated 2-bromo-N,N-dimethylethanamine supports the formation of this intermediate. The bromonium ion intermediate-involved halogen transfer mechanism is supported by an examination of the ion/molecule reaction between isolated ethylenebromonium ion and triethylamine, which generates the N-bromo-N,N,N-triethylammonium cation. For other halogens, Cl and I also can be involved in similar intramolecular halogen transfer, but F cannot be involved. With the elongation of the carbon chain between the halogen (bromine as a representative example) and amine, the migration ability of halogen decreases. When the carbon chain contains two or three CH2 units (n = 1, 2), formal bromine cation transfer can take place, and the transfer is easier when n = 1. When the carbon chain contains four or five CH2 units (n = 3, 4), formal bromine cation transfer does not occur, probably because the five- and six-membered cyclic bromonium ions are very stable and do not donate the bromine to the amine.
Collapse
Affiliation(s)
- Yunfeng Chai
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | | | - Lei Yue
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
| | - You Jiang
- National Institute of Metrology, Beijing, 100013, China
| | - Yuanjiang Pan
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, China.
| | - Xiang Fang
- National Institute of Metrology, Beijing, 100013, China.
| |
Collapse
|