Monolignol acylation and lignin structure in non-woody plants: A 2D-NMR study.
2D NMR revealed a correspondence between the molecular structure of lignins and their degree of acylation in several nonwoody angiosperms characterized by different lignin acylation types (acetate and/or p-coumarate esters) and extents (up to more that 90% of units). Some of the lignin substructures identified showed that acylation is produced at the monolignol level. Direct evidence was also provided by GC-MS identification of γ-acetylated sinapyl alcohol among plant extractives. Taking the above findings together, it is proposed that some angiosperms could use monolignol acylation as a mechanism to regulate the structure of lignin. In this way, acylation would result in lower presence of resinols and other β-β' interunit linkages in S-rich lignins, promoting formation of a highly-etherified (β-O-4' linked) and more labile lignin polymer. In contrast, low (or null) acylation would result in lignins with higher content of C-C interunit linkages, that will be more recalcitrant towards chemical and/or biological degradation.
Main Authors: | , , , , , , |
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Format: | comunicación de congreso biblioteca |
Language: | English |
Published: |
2008-08-26
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Subjects: | Nonwoody plants, Hemp, Sisal, Abaca, Lignin, Gamma-acylation, Acetates, p-Coumarates, |
Online Access: | http://hdl.handle.net/10261/86382 |
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