Dearomatization drives complexity generation in freshwater organic matter

Siyu Li, Mourad Harir, David Bastviken, Philippe Schmitt-Kopplin, Michael Gonsior, Alex Enrich-Prast, Juliana Valle and Norbert Hertkorn ()
Additional contact information
Siyu Li: Research Unit Analytical Biogeochemistry (BGC), Helmholtz Munich, German Research Center for Environmental Health
Mourad Harir: Research Unit Analytical Biogeochemistry (BGC), Helmholtz Munich, German Research Center for Environmental Health
David Bastviken: Linköping University
Philippe Schmitt-Kopplin: Research Unit Analytical Biogeochemistry (BGC), Helmholtz Munich, German Research Center for Environmental Health
Michael Gonsior: University of Maryland Center for Environmental Science
Alex Enrich-Prast: Linköping University
Juliana Valle: Research Unit Analytical Biogeochemistry (BGC), Helmholtz Munich, German Research Center for Environmental Health
Norbert Hertkorn: Research Unit Analytical Biogeochemistry (BGC), Helmholtz Munich, German Research Center for Environmental Health

Nature, 2024, vol. 628, issue 8009, 776-781

Abstract: Abstract Dissolved organic matter (DOM) is one of the most complex, dynamic and abundant sources of organic carbon, but its chemical reactivity remains uncertain1–3. Greater insights into DOM structural features could facilitate understanding its synthesis, turnover and processing in the global carbon cycle4,5. Here we use complementary multiplicity-edited 13C nuclear magnetic resonance (NMR) spectra to quantify key substructures assembling the carbon skeletons of DOM from four main Amazon rivers and two mid-size Swedish boreal lakes. We find that one type of reaction mechanism, oxidative dearomatization (ODA), widely used in organic synthetic chemistry to create natural product scaffolds6–10, is probably a key driver for generating structural diversity during processing of DOM that are rich in suitable polyphenolic precursor molecules. Our data suggest a high abundance of tetrahedral quaternary carbons bound to one oxygen and three carbon atoms (OCqC3 units). These units are rare in common biomolecules but could be readily produced by ODA of lignin-derived and tannin-derived polyphenols. Tautomerization of (poly)phenols by ODA creates non-planar cyclohexadienones, which are subject to immediate and parallel cycloadditions. This combination leads to a proliferation of structural diversity of DOM compounds from early stages of DOM processing, with an increase in oxygenated aliphatic structures. Overall, we propose that ODA is a key reaction mechanism for complexity acceleration in the processing of DOM molecules, creation of new oxygenated aliphatic molecules and that it could be prevalent in nature.

Date: 2024
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/s41586-024-07210-9 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:628:y:2024:i:8009:d:10.1038_s41586-024-07210-9

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/s41586-024-07210-9

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().