Demethylation and tannin-like properties of guaiacyl/syringyl-type and syringyl-type dehydrogenation polymers using iodocyclohexane
The demethylation of guaiacyl/syringyl (G/S)-type (G/S = 1/1) and syringyl (S)-type dehydrogenation polymers (DHPs) using iodocyclohexane (ICH) under reflux in DMF was performed to afford demethylated G/S- and S-DHPs in moderate yields. Along with significant structural changes, such as side-chain c...
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Published in | Journal of wood science Vol. 68; no. 1; pp. 51 - 7 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Singapore
Springer Nature Singapore
01.12.2022
Springer Nature B.V SpringerOpen |
Subjects | |
Online Access | Get full text |
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Summary: | The demethylation of guaiacyl/syringyl (G/S)-type (G/S = 1/1) and syringyl (S)-type dehydrogenation polymers (DHPs) using iodocyclohexane (ICH) under reflux in DMF was performed to afford demethylated G/S- and S-DHPs in moderate yields. Along with significant structural changes, such as side-chain cleavage and recondensation, as observed using heteronuclear single quantum coherence (HSQC) NMR spectra, the phenolic-OH content of the demethylated DHPs increased, as expected. The tannin-like properties, such as the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging ability, iron(III) binding ability, and bovine serum albumin (BSA) adsorption ability, of the demethylated DHPs increased with increasing reaction time. In particular, the BSA adsorption ability was significantly enhanced by demethylation of the G/S- and S-DHPs, and was better than that of G-DHP reported previously. These results indicate that hardwood lignin containing both G and S units is more suitable than softwood lignin containing only G units for functionalization through demethylation into a tannin-like polymer, which has applications as a natural oxidant, metal adsorbent, and protein adsorbent. |
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ISSN: | 1435-0211 1611-4663 |
DOI: | 10.1186/s10086-022-02059-w |