Structural characterization of wheat straw lignin. Evidence for a novel monomer in grasses.

The structure of the lignin in wheat straw has been investigated by 2D-NMR and DFRC. It is a p-hydroxyphenyl-guaiacyl-syringyl lignin (with a H:G:S ratio of 6:64:30) associated with p-coumarates and ferulates. The main substructures present are β–O–4´-ethers (~75%), followed by phenylcoumarans (~11%), with lower amounts of other units. The lignin is partially acylated (~10%) at the γ-carbon, predominantly with acetates that preferentially acylate guaiacyl (12%) rather than syringyl (1%) units. p-Coumarate esters were barely detectable (<1%) on monomer conjugates released by selectively cleaving β-ethers in DFRC, indicating that they might be preferentially involved in condensed or terminal structures. A major new finding is that the flavone tricin is apparently incorporated into the lignins.

Bibliographic Details

Main Authors:	Río Andrade, José Carlos del, Rencoret, Jorge, Prinsen, Pepijn, Martínez, Ángel T., Gutiérrez Suárez, Ana, Ralph, John
Format:	comunicación de congreso biblioteca
Language:	English
Published:	2013-06-12
Subjects:	Wheat straw, Milled wood lignin, HSQC, DFRC, p-Coumarates, Tricin,
Online Access:	http://hdl.handle.net/10261/86427
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