Structural Characterization of Guaiacyl-rich Lignins in Flax (Linum usitatissimum) Fibers and Shives
Río Andrade, José Carlos del | Rencoret, Jorge | Gutiérrez Suárez, Ana | Nieto, Lidia | Jiménez-Barbero, Jesús | Martínez, Ángel T. | Consejo Superior de Investigaciones Científicas (España) | European Commission | Ministerio de Educación (España)
The structural characteristics of the lignins from flax (Linum usitatissimum) fibers and shives were studied. Significant differences in the content and composition of the lignin from both parts were observed. The lignin contents were 3.8% in the fibers and 29.0% in the shives. Analysis by Py-GC/MS indicated a H:G:S molar ratio of 13:72:15 in the milled wood lignin (MWL) isolated from flax fibers and a molar ratio of 5:87:8 in the MWL isolated from flax shives. In addition, 2D-NMR showed a predominance of β-O-4 aryl ether linkages, followed by β-5 phenylcoumaran and β-β resinol-type linkages in both MWLs, with a higher content of condensed linkages in flax shives. Thioacidolysis (followed by Raney nickel desulfurization) gave further information on the lignin units involved in the different linkages and confirmed the enrichment of G units. The thioacidolysis dimers released were similar from both lignins, with a predominance of the β-5 followed by β-1 and 5-5 structures.
Показать больше [+] Меньше [-]This study has been funded by the Spanish Project AGL2008-00709, CSIC Projects 200640I039 and 201040E075, and EU Projects BIORENEW (NMP2-CT-2006-026456) and LIGNODECO(KBBE-244362). J.R. thanks the Spanish CSIC for an I3P fellowship; G.M. thanks the Spanish Ministry of Education for a FPI fellowship.
Показать больше [+] Меньше [-]Peer reviewed
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