(-)ESI/CAD MSn Procedure for Sequencing Lignin Oligomers Based on a Study of Synthetic Model Compounds with β-O-4 and 5-5 Linkages

Huaming Sheng, Weijuan Tang, Jinshan Gao, James S. Riedeman, Guannan Li, Tiffany M. Jarrell, Matthew R. Hurt, Linan Yang, Priya Murria, Xin Ma, John J. Nash, Hilkka I. Kenttämaa

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

Seven synthesized G-lignin oligomer model compounds (ranging in size from dimers to an octamer) with 5-5 and/or β-O-4 linkages, and three synthesized S-lignin model compounds (a dimer, trimer, and tetramer) with β-O-4 linkages, were evaporated and deprotonated using negative-ion mode ESI in a linear quadrupole ion trap/Fourier transform ion cyclotron resonance mass spectrometer. The collision-activated dissociation (CAD) fragmentation patterns (obtained in MS2 and MS3 experiments, respectively) for the negative ions were studied to develop a procedure for sequencing unknown lignin oligomers. On the basis of the observed fragmentation patterns, the measured elemental compositions of the most abundant fragment ions, and quantum chemical calculations, the most important reaction pathways and likely mechanisms were delineated. Many of these reactions occur via charge-remote fragmentation mechanisms. Deprotonated compounds with only β-O-4 linkages, or both 5-5 and β-O-4 linkages, showed major 1,2-eliminations of neutral compounds containing one, two, or three aromatic rings. The most likely mechanisms for these reactions are charge-remote Maccoll and retro-ene eliminations resulting in the cleavage of a β-O-4 linkage. Facile losses of H2O and CH2O were also observed for all deprotonated model compounds, which involve a previously published charge-driven mechanism. Characteristic "ion groups" and "key ions" were identified that, when combined with their CAD products (MS3 experiments), can be used to sequence unknown oligomers.

Original languageEnglish
Pages (from-to)13089-13096
Number of pages8
JournalAnalytical Chemistry
Volume89
Issue number24
DOIs
StatePublished - 19 Dec 2017

Fingerprint Dive into the research topics of '(-)ESI/CAD MS<sup>n</sup> Procedure for Sequencing Lignin Oligomers Based on a Study of Synthetic Model Compounds with β-O-4 and 5-5 Linkages'. Together they form a unique fingerprint.

  • Cite this

    Sheng, H., Tang, W., Gao, J., Riedeman, J. S., Li, G., Jarrell, T. M., Hurt, M. R., Yang, L., Murria, P., Ma, X., Nash, J. J., & Kenttämaa, H. I. (2017). (-)ESI/CAD MSn Procedure for Sequencing Lignin Oligomers Based on a Study of Synthetic Model Compounds with β-O-4 and 5-5 Linkages. Analytical Chemistry, 89(24), 13089-13096. https://doi.org/10.1021/acs.analchem.7b01911