Differences in the composition of lipophilic extractives and lignin in Brazilian woods from different eucalypt hybrids
The chemical characteristics of the woods from several eucalypt hybrids from the Brazilian Genolyptus program were studied. Analyses of the lipophilic extractives indicated a similar composition in all eucalypt hybrids, which were dominated by sitosterol, sitosterol esters and sitosteryl 3β-D-glucopyranoside, that are responsible for pitch deposition during kraft pulping of eucalypt wood. The chemical composition and structure of lignins were characterized by Py-GC/MS and 2D-NMR. All the lignins showed a predominance of β-O-4 ether linkages (75-79% of total side-chains), followed by β-β resinol-type linkages (9-11%) and lower amounts of β-5 phenylcoumaran-type, and β-1 spirodienone-type linkages. The lignin from the hybrid G1UGL presented the highest S/G ratio and the highest proportion of β-O-4 linkages, and therefore, it is foreseen that this wood will be more easily delignifiable than the other selected eucalypt hybrids.
Main Authors: | , , , , , , , |
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Format: | capítulo de libro biblioteca |
Language: | English |
Published: |
American Chemical Society
2012-08-27
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Subjects: | Eucalyptus wood, Lignin, Lipids, |
Online Access: | http://hdl.handle.net/10261/86335 |
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