Covalently bound humin-lignin hybrids as important novel substructures in organosolv spruce lignins.

Autor: Thoresen PP; Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 971-87, Sweden., Lange H; Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 971-87, Sweden; Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy; NBFC - National Biodiversity Future Center, 90133 Palermo, Italy. Electronic address: heiko.lange@unimib.it., Rova U; Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 971-87, Sweden., Christakopoulos P; Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 971-87, Sweden., Matsakas L; Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 971-87, Sweden. Electronic address: leonidas.matsakas@ltu.se.
Jazyk: angličtina
Zdroj: International journal of biological macromolecules [Int J Biol Macromol] 2023 Apr 01; Vol. 233, pp. 123471. Date of Electronic Publication: 2023 Feb 01.
DOI: 10.1016/j.ijbiomac.2023.123471
Abstrakt: Organosolv lignins (OSLs) are important byproducts of the cellulose-centred biorefinery that need to be converted in high value-added products for economic viability. Yet, OSLs occasionally display characteristics that are unexpected looking at the lignin motifs present. Applying advanced NMR, GPC, and thermal analyses, isolated spruce lignins were analysed to correlate organosolv process severity to the structural details for delineating potential valorisations. Very mild conditions were found to not fractionate the biomass, causing a mix of sugars, lignin-carbohydrate complexes (LCCs), and corresponding dehydration/degradation products and including pseudo-lignins. Employing only slightly harsher conditions promote fractionation, but also formation of sugar degradation structures that covalently incorporate into the oligomeric and polymeric lignin structures, causing the isolated organosolv lignins to contain lignin-humin hybrid (HLH) structures not yet evidenced as such in organosolv lignins. These structures effortlessly explain observed unexpected solubility issues and unusual thermal responses, and their presence might have to be acknowledged in downstream lignin valorisation.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023. Published by Elsevier B.V.)
Databáze: MEDLINE