| Characterization of residual lignin after SO(2)-catalyzed steam explosion and enzymatic hydrolysis of Eucalyptus viminalis wood chips. | |
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MedLine Citation:
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PMID: 10794625 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The lignin component found in both water insoluble (WI) and water and alkali insoluble (WIA) fractions derived from SO(2)-impregnated steam-exploded eucalyptus chips (SEE) was isolated and characterized. Dioxane lignins with a sugar content lower than 2% (w/w) were obtained after each material was treated with commercial cellulases. The C9 formulas of both SEE-WI and SEE-WIA dioxane lignins were C(9)H(6.83)N(0.04)O(2.24)(OCH(3))(1.21)(OH(aro))(0.56)(OH(ali))(0. 77) and C(9)H(8.65)N(0.29)O(1.97)(OCH(3))(0.90)(OH(aro))(0. 46)(OH(ali))(1.02), respectively. The weight-average molecular weight (M(w)) of the SEE-WI lignin corresponded to 3.85 kDa, whereas the SEE-WIA lignin had an M(w) of 3.66 kDa for the same polydispersity of 2.4. The SEE-WIA lignin was shown to be more thermally stable than the SEE-WI lignin, requiring temperatures in the range of 520 degrees C for complete degradation. FTIR and (1)H NMR analyses of both untreated and peracetylated lignin fractions showed that (a) the alkali insoluble lignin contained a relatively higher degree of substitution in aromatic rings per C9 unit and that (b) alkaline extraction removed lignin fragments containing appreciable amounts of phenolic hydroxyl groups. |
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Authors:
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L P Ramos; A L Mathias; F T Silva; A R Cotrim; A L Ferraz; C L Chen |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of agricultural and food chemistry Volume: 47 ISSN: 0021-8561 ISO Abbreviation: J. Agric. Food Chem. Publication Date: 1999 Jun |
Date Detail:
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Created Date: 2000-08-16 Completed Date: 2000-08-16 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 0374755 Medline TA: J Agric Food Chem Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 2295-302 Citation Subset: IM |
Affiliation:
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Centro de Pesquisa em Química Aplicada, Departamento de Química, Universidade Federal do Paraná, Curitiba, Brazil. lramos@quimica.ufpr.br |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Cellulase Eucalyptus* Hot Temperature Hydrolysis Lignin / analysis, chemistry* Plants, Medicinal* Solubility Spectroscopy, Fourier Transform Infrared Sulfur Dioxide Wood* |
| Chemical | |
Reg. No./Substance:
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7446-09-5/Sulfur Dioxide; 9005-53-2/Lignin; EC 3.2.1.4/Cellulase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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