Determination of chemical shifts in 6-condensed syringylic lignin model compounds

Lucas Lagerquist; Jani Rahkila; Patrik Eklund

doi:10.1515/hf-2021-0093

Article

Determination of chemical shifts in 6-condensed syringylic lignin model compounds

Lucas Lagerquist , Jani Rahkila and Patrik Eklund

Published/Copyright: December 24, 2021

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From the journal Holzforschung Volume 76 Issue 3

Abstract

A small library of 6-substituted syringyl model compounds with aliphatic, carboxylic, phenylic, benzylic alcohols and brominated substituents were prepared. The influence of the substituents on the chemical shifts of the compounds was analyzed. All of model compounds showed a characteristic increase in the ¹³C NMR chemical shift of the methoxy group vicinal to the substitution. This ¹³C NMR peak and its corresponding correlation peak in HSQC could potentially be used to identify 6-condensation in syringylic lignin samples.

Keywords: condensation; HSQC; lignin model compounds; NMR-spectroscopy; syringyl

Corresponding author: Patrik Eklund, Faculty of Science and Engineering, Åbo Akademi University, Henriksgatan 2, 20500 Turku/Åbo, Finland, E-mail: paeklund@abo.fi

Acknowledgments

The authors are grateful to Alex Dickens for the HRMS analysis.

Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
Research funding: None declared.
Conflict of interest statement: The authors declare no conflicts of interest regarding this article.

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Supplementary Material

The online version of this article offers supplementary material (https://doi.org/10.1515/hf-2021-0093).

Received: 2021-05-10

Accepted: 2021-10-22

Published Online: 2021-12-24

Published in Print: 2022-03-28

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Supplementary Material

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https://doi.org/10.1515/hf-2021-0093

Keywords for this article

condensation; HSQC; lignin model compounds; NMR-spectroscopy; syringyl