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Feng YQ, Zhang P, Jian JZ, Wang ZW, Tian XL, Luo GY, Yang WD. Study on 2-arylbenzo[ b]furans from Itea omeiensis and their fragmentation patterns with Q-Orbitrap mass spectrometry. Nat Prod Res 2024; 38:3118-3129. [PMID: 37245178 DOI: 10.1080/14786419.2023.2216344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/24/2023] [Accepted: 05/10/2023] [Indexed: 05/29/2023]
Abstract
One new 2-arylbenzo[b]furan named iteafuranal F (1) as well as two known analogues (2-3) were isolated from the 95% EtOH extract of aerial parts of Itea omeiensis. Their chemical structures were constructed based on extensive analyses of UV, IR, 1D/2D NMR and HRMS spectra. Antioxidant assays revealed significant superoxide anion radical scavenging capacity of 1 with IC50 value of 0.66 mg/mL, which was comparable to the efficiency of positive control of luteolin. In addition, the preliminary MS fragmentation patterns in negative ion mode were established to distinguish 2-arylbenzo[b]furans with C-10 in different oxidation states: the characteristic loss of CO molecule [M-H-28]- was observed for 3-formyl-2-arylbenzo[b]furans, and the loss of CH2O fragment [M-H-30]- for 3-hydroxymethyl-2-arylbenzo[b]furans, and the loss of CO2 fragment [M-H-44]- for 2-arylbenzo[b]furan-3-carboxylic acids.
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Affiliation(s)
- Yun-Qian Feng
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, People's Republic of China
| | - Pan Zhang
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, People's Republic of China
| | - Jin-Zhen Jian
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, People's Republic of China
| | - Zhi-Wei Wang
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, People's Republic of China
| | - Xiao-Long Tian
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, People's Republic of China
| | - Guo-Yong Luo
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, People's Republic of China
| | - Wu-De Yang
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, People's Republic of China
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Dias HJ, Santos WH, Filho LCS, Crevelin EJ, McIndoe JS, Vessecchi R, Crotti AEM. Electrospray ionization tandem mass spectrometry of 4-aryl-3,4-dihydrocoumarins. JOURNAL OF MASS SPECTROMETRY : JMS 2024; 59:e5062. [PMID: 38831552 DOI: 10.1002/jms.5062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 05/06/2024] [Accepted: 05/14/2024] [Indexed: 06/05/2024]
Abstract
We have investigated the gas-phase fragmentation reactions of 11 synthetic 4-aryl-3,4-dihydrocoumarins by electrospray ionization tandem mass spectrometry (ESI-MS/MS) on a quadrupole-time-of flight (Q-TOF) hybrid mass spectrometer. We have also estimated thermochemical data for the protonated coumarins (precursor ion A) and product ion structures by computational chemistry at a B3LYP level of theory to establish the ion structures and to rationalize the fragmentation pathways. The most abundant ions in the product ion spectra of coumarins 1-11 resulted from C8H8O2, CO2, C4H4O3, C8H10O3, C8H8O2, and CH3OH eliminations through retro-Diels-Alder (RDA) reactions, remote hydrogen rearrangements (β-eliminations), and β-lactone ring contraction. Although the investigated coumarins shared most of the fragmentation pathways, formation of a benzylic product ion and its corresponding tropylium ion was diagnostic of the substituents at ring C. The thermochemical data revealed that the nature and position of the substituents at ring C played a key role in the formation of this product ion and determined its relative intensity in the product ion spectrum. The results of this study contribute to knowledge of the gas-phase ion chemistry of this important class of organic compounds.
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Affiliation(s)
- Herbert J Dias
- Department of Chemistry, Faculty of Philosophy, Science and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- Goiano Federal Institute of Education, Science, and Technology, Campus Urutaí, Urutaí, Brazil
| | - William H Santos
- Department of Chemistry, Faculty of Sciences at Bauru, São Paulo State University, Bauru, Brazil
| | - Luis C S Filho
- Department of Chemistry, Faculty of Sciences at Bauru, São Paulo State University, Bauru, Brazil
| | - Eduardo J Crevelin
- Department of Chemistry, Faculty of Philosophy, Science and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - J Scott McIndoe
- Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada
| | - Ricardo Vessecchi
- Department of Chemistry, Faculty of Philosophy, Science and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Antônio E M Crotti
- Department of Chemistry, Faculty of Philosophy, Science and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
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Dias HJ, Crevelin EJ, Palaretti V, Vessecchi R, Crotti AEM. Electrospray ionization tandem mass spectrometry of deprotonated dihydrobenzofuran neolignans. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e8990. [PMID: 33119941 DOI: 10.1002/rcm.8990] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/21/2020] [Accepted: 10/24/2020] [Indexed: 06/11/2023]
Abstract
RATIONALE Although dihydrobenzofuran neolignans (DBNs) display a wide diversity of biological activities, the identification of their in vivo metabolites using liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) remains a challenge to be overcome. Recently, ESI-MS/MS data of protonated DBNs have been reported, but they were shown to be limited due to the scarcity of diagnostic ions. METHODS The gas-phase fragmentation pathways of a series of biologically active synthetic benzofuran neolignans (BNs) and DBNs were elucidated by means of negative ESI accurate-mass tandem and sequential mass spectrometry, and thermochemical data estimated using computational chemistry and the B3LYP/6-31+G(d,p) model. RESULTS Deprotonated DBNs produced more diagnostic product ions than the corresponding protonated molecules. Moreover, a series of odd-electron product ions (radical anions) were detected, which has not been reported for protonated DBNs. Direct C2 H3 O2 • elimination from the precursor ion (deprotonated molecule) only occurred for the BNs and can help to distinguish these compounds from the DBNs. The mechanism through which the [M - H - CH3 OH]- ion is formed is strongly dependent on specific structural features. CONCLUSIONS The negative ion mode provides much more information than the positive ion mode (at least one diagnostic product ion was detected for all the analyzed compounds) and does not require the use of additives to produce the precursor ions (deprotonated molecules).
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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
| | - Eduardo J Crevelin
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Vinicius Palaretti
- 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
| | - 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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Vieira TM, Orenha RP, Crevelin EJ, Furtado SSP, Vessecchi R, Parreira RLT, Crotti AEM. Electrospray ionization tandem mass spectrometry of monoketone curcuminoids. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34 Suppl 3:e8699. [PMID: 31845428 DOI: 10.1002/rcm.8699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/20/2019] [Accepted: 12/12/2019] [Indexed: 06/10/2023]
Abstract
RATIONALE Although monoketone curcuminoids (MKCs) have been largely investigated due to their biological activities, data on the gas-phase fragmentation reactions of protonated MKCs under collision-induced dissociation (CID) conditions are still scarce. Here, we combined electrospray ionization tandem mass spectrometry (ESI-MS/MS) data, multiple-stage mass spectrometry (MSn ), deuterium exchange experiments, accurate-mass data, and thermochemical data estimated by computational chemistry to elucidate and to rationalize the fragmentation pathways of eleven synthetic MKCs. METHODS The MKCs were synthesized by Claisen-Schmidt condensation under basic (1-9) or acidic (10-11) conditions. ESI-CID-MS/MS analyses and deuterium-exchange experiments were carried out on a triple quadrupole mass spectrometer. MSn analyses on an ion trap mass spectrometer helped to elucidate the fragmentation pathways. Accurate-mass data and thermochemical data, obtained at the B3LYP/6-31+G(d,p) level of theory, were used to support the ion structures. RESULTS The most intense product ions were the benzyl ions ([C7 H2 R1 R2 R3 R4 R5 ]+ ) and the acylium ions ([M + H - C8 H3 R1 R2 R3 R4 R5 ]+ ), which originated directly from the precursor ion as a result of two competitive hydrogen rearrangements. Product ions [M + H - H2 O]+ and [M + H - C6 HR1 R2 R3 R4 R5 ]+ , which are formed after Nazarov cyclization, were also common to all the analyzed compounds. In addition, •Br and •Cl eliminations were diagnostic for the presence of these halogen atoms at the aromatic ring, whereas •CH3 eliminations were useful to identify the methyl and methoxy groups attached to this same ring. Nazarov cyclization in the gas phase occurred for all the investigated MKCs and did not depend on the presence of the hydroxyl group at the aromatic ring. However, the presence and the position of a hydroxyl group at the aromatic rings played a key role in the Nazarov cyclization mechanism. CONCLUSIONS Our results reinforce some aspects of the fragmentation pathways previously published for 1,5-bis-(2-methoxyphenyl)-1,4-pentadien-3-one and 1,5-bis-(2-hydroxyphenyl)-1,4-pentadien-3-one. The alternative fragmentation mechanism proposed herein can explain the fragmentation of a wider diversity of monoketone curcuminoids.
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Affiliation(s)
- Tatiana M Vieira
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Monte Alegre, CEP 14040-901, Ribeirão Preto, SP, Brazil
| | - Renato P Orenha
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil
| | - Eduardo J Crevelin
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Monte Alegre, CEP 14040-901, Ribeirão Preto, SP, Brazil
| | - Saulo S P Furtado
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil
| | - Ricardo Vessecchi
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Monte Alegre, CEP 14040-901, Ribeirão Preto, SP, Brazil
| | - Renato L T Parreira
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil
| | - Antônio E M Crotti
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Monte Alegre, CEP 14040-901, Ribeirão Preto, SP, Brazil
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