Fast and metastable fragmentation of deprotonated d-fructose – A combined experimental and computational study

Flosadóttir, Helga Dögg; Bald, Ilko; Ingólfsson, Oddur

doi:10.1016/j.ijms.2011.05.016

Cited by 11 publications

(6 citation statements)

References 29 publications

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“…These include studies on the metastable decay of the deprotonated nucleobases, nucleosides and the ribophosphate [44][45][46][47] as well as the sugars ribose [47] and fructose. [47,48] In these studies the focus resides on the role of the deprotonation site in determining the fragmentation path as reviewed in a recent colloquium [44]. It has been found that for thymine, NCOis the most significant fragmentation channel, which strongly depends on the deprotonation site.…”

Section: Introductionmentioning

confidence: 99%

NCO^–, a Key Fragment Upon Dissociative Electron Attachment and Electron Transfer to Pyrimidine Bases: Site Selectivity for a Slow Decay Process

Silva

Matias

Almeida

et al. 2013

J. Am. Soc. Mass Spectrom.

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We report gas phase studies on NCO(-) fragment formation from the nucleobases thymine and uracil and their N-site methylated derivatives upon dissociative electron attachment (DEA) and through electron transfer in potassium collisions. For comparison, the NCO(-) production in metastable decay of the nucleobases after deprotonation in matrix assisted laser desorption/ionization (MALDI) is also reported. We show that the delayed fragmentation of the dehydrogenated closed-shell anion into NCO(-) upon DEA proceeds few microseconds after the electron attachment process, indicating a rather slow unimolecular decomposition. Utilizing partially methylated thymine, we demonstrate that the remarkable site selectivity of the initial hydrogen loss as a function of the electron energy is preserved in the prompt as well as the metastable NCO(-) formation in DEA. Site selectivity in the NCO(-) yield is also pronounced after deprotonation in MALDI, though distinctly different from that observed in DEA. This is discussed in terms of the different electronic states subjected to metastable decay in these experiments. In potassium collisions with 1- and 3-methylthymine and 1- and 3-methyluracil, the dominant fragment is the NCO(-) ion and the branching ratios as a function of the collision energy show evidence of extraordinary site-selectivity in the reactions yielding its formation.

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Section: Introductionmentioning

confidence: 99%

NCO^–, a Key Fragment Upon Dissociative Electron Attachment and Electron Transfer to Pyrimidine Bases: Site Selectivity for a Slow Decay Process

Silva

Matias

Almeida

et al. 2013

J. Am. Soc. Mass Spectrom.

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“… 19 , realizing the “one-pot” synthesis of HMF from glucose with relatively high conversion and selectivity. On the other hand, glucose has lower acidity than fructose 20 21 22 23 and hence is less reactive under basic conditions. Recently, Liu et al .…”

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confidence: 99%

“…D-glucose (monomer of cellulosic biomass) and D-fructose (pivotal intermediate for cellulose utilization), in both α- and β-anomers, have been considered. To best of our knowledge, all previous sugar conversions focused on O sites, which are preferred over C sites during protonation 16 17 18 36 37 38 and deprotonation 20 21 22 23 . Here a systematic study was also conducted for O-centered sugar radicals, and comparisons with the results of C-centered radicals clearly indicated that the formation of C-centered radicals is always preferential, thus suggesting the possibility to activate and convert the C-H bonds of biomass sugars.…”

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confidence: 99%

Radicalization and Radical Catalysis of Biomass Sugars: Insights from First-principles Studies

Yang

Zhu

Zou

et al. 2016

Sci Rep

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Ab initio and density functional calculations are conducted to investigate the radicalization processes and radical catalysis of biomass sugars. Structural alterations due to radicalization generally focus on the radicalized sites, and radicalization affects H-bonds in D-fructofuranose more than in D-glucopyranose, potentially with outcome of new H-bonds. Performances of different functionals and basis sets are evaluated for all radicalization processes, and enthalpy changes and Gibbs free energies for these processes are presented with high accuracy, which can be referenced for subsequent experimental and theoretical studies. It shows that radicalization can be utilized for direct transformation of biomass sugars, and for each sugar, C rather than O sites are always preferred for radicalization, thus suggesting the possibility to activate C-H bonds of biomass sugars. Radical catalysis is further combined with Brønsted acids, and it clearly states that functionalization fundamentally regulates the catalytic effects of biomass sugars. In presence of explicit water molecules, functionalization significantly affects the activation barriers and reaction energies of protonation rather than dehydration steps. Tertiary butyl and phenyl groups with large steric hindrances or hydroxyl and amino groups resulting in high stabilities for protonation products drive the protonation steps to occur facilely at ambient conditions.

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“…For the other metastable ions, most fragments retained the charge at C6. Good correlation was found between predictions from classical dynamics simulations and the experimental results (Flosadottir, Bald, & Ingólfsson, ).…”

Section: Fragmentationmentioning

confidence: 66%

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2011–2012

Harvey

2015

Mass Spectrometry Reviews

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This review is the seventh update of the original article published in 1999 on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2012. General aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, and fragmentation are covered in the first part of the review and applications to various structural types constitute the remainder. The main groups of compound are oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. Also discussed are medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 36:255-422, 2017.

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Fast and metastable fragmentation of deprotonated d-fructose – A combined experimental and computational study

Cited by 11 publications

References 29 publications

NCO^–, a Key Fragment Upon Dissociative Electron Attachment and Electron Transfer to Pyrimidine Bases: Site Selectivity for a Slow Decay Process

NCO^–, a Key Fragment Upon Dissociative Electron Attachment and Electron Transfer to Pyrimidine Bases: Site Selectivity for a Slow Decay Process

Radicalization and Radical Catalysis of Biomass Sugars: Insights from First-principles Studies

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2011–2012

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Fast and metastable fragmentation of deprotonated d-fructose – A combined experimental and computational study

Cited by 11 publications

References 29 publications

NCO–, a Key Fragment Upon Dissociative Electron Attachment and Electron Transfer to Pyrimidine Bases: Site Selectivity for a Slow Decay Process

NCO–, a Key Fragment Upon Dissociative Electron Attachment and Electron Transfer to Pyrimidine Bases: Site Selectivity for a Slow Decay Process

Radicalization and Radical Catalysis of Biomass Sugars: Insights from First-principles Studies

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2011–2012

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Product

Resources

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NCO^–, a Key Fragment Upon Dissociative Electron Attachment and Electron Transfer to Pyrimidine Bases: Site Selectivity for a Slow Decay Process

NCO^–, a Key Fragment Upon Dissociative Electron Attachment and Electron Transfer to Pyrimidine Bases: Site Selectivity for a Slow Decay Process