Comprehensive study on the chemical structure of dioxane lignin from plantation Eucalyptus globulus wood

Citation
Dv. Evtuguin et al., Comprehensive study on the chemical structure of dioxane lignin from plantation Eucalyptus globulus wood, J AGR FOOD, 49(9), 2001, pp. 4252-4261
Citations number
53
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Agricultural Chemistry","Chemistry & Analysis
Journal title
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
ISSN journal
0021-8561 → ACNP
Volume
49
Issue
9
Year of publication
2001
Pages
4252 - 4261
Database
ISI
SICI code
0021-8561(200109)49:9<4252:CSOTCS>2.0.ZU;2-N
Abstract
Results of a comprehensive study on the chemical structure of lignin from p lantation Eucalyptus globulus Labill are presented. Lignin has been isolate d by a modified mild acidolysis method and thoroughly characterized by func tional group analysis, by a series of degradation techniques (nitrobenzene oxidation, permanganate oxidation, thioacidolysis, and Py-GC-MS), and H-1 a nd C-13 NMR spectroscopy. Plantation Eucalyptus globulus lignin was found t o be of the S/G type with an extremely high proportion of syringyl (S) unit s (82-86%) and a minor proportion of p-hydrophenyl propane (H) units (rough ly 2-3 mol %). Unknown C-6 substituted and 4-O-5 ', type syringyl substruct ures represent about 65% of lignin "condensed" structures. Eucalypt lignin showed high abundance of beta -O-4 (0.56/C-6) structures and units linked b y 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 distribut ion of lignin with the center of gravity of mass distribution around 2500 u .