|
authors |
Evtuguin, DV; Neto, CP; Silva, AMS; Domingues, PM; Amado, FML; Robert, D; Faix, O |
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journal |
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY |
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author keywords |
lignin; Eucalyptus globulus; functional group analysis; nitrobenzene oxidation; permanganate oxidation; thioacidolysis; analytical pyrolysis; ESIMS; H-1 NMR spectroscopy; C-13 NMR spectroscopy |
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keywords |
MOLECULAR-WEIGHT; CAMALDULENSIS; NUCLEAR |
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abstract |
Results of a comprehensive study on the chemical structure of lignin from plantation Eucalyptus globulus Labill are presented. Lignin has been isolated by a modified mild acidolysis method and thoroughly characterized by functional group analysis, by a series of degradation techniques (nitrobenzene oxidation, permanganate oxidation, thioacidolysis, and Py-GC-MS), and H-1 and C-13 NMR spectroscopy. Plantation Eucalyptus globulus lignin was found to be of the S/G type with an extremely high proportion of syringyl (S) units (82-86%) and a minor proportion of p-hydrophenyl propane (H) units (roughly 2-3 mol %). Unknown C-6 substituted and 4-O-5 ', type syringyl substructures represent about 65% of lignin "condensed" structures. Eucalypt lignin showed high abundance of beta -O-4 (0.56/C-6) structures and units linked by alpha -O-4 bonds (0.23/C-6). The proportion of phenylcoumaran structures was relatively low (0.03/C-6). Different kinds of beta-beta substructures (pino-/syringaresinol and isotaxiresinol types) in a total amount of 0.13/C-6 were detected. ESI-MS analysis revealed a wide molecular weight distribution of lignin with the center of gravity of mass distribution around 2500 u. |
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publisher |
AMER CHEMICAL SOC |
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issn |
0021-8561 |
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year published |
2001 |
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volume |
49 |
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issue |
9 |
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beginning page |
4252 |
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ending page |
4261 |
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digital object identifier (doi) |
10.1021/jf010315d |
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web of science category |
Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology |
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subject category |
Agriculture; Chemistry; Food Science & Technology |
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unique article identifier |
WOS:000171214900018
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