Chemical composition and structural features of the macromolecular components of plantation Acacia mangium wood.
The wood of Acacia mangium, a prominent fast-growing plantation species used in the pulp-and-paper industry and, so far, poorly investigated for its chemical structure, was submitted to a detailed characterization of its main macromolecular components. Lignin (28% wood weight) isolated by mild acidolysis and characterized by permanganate oxidation, 1H and 13C NMR, and GPC, showed a very low content of syringylpropane-derived units (S:G:H of 48:49:3), a high degree of condensation, a low content of beta-O-4 ( approximately 0.40-0.43 per C6) structures, and a Mw of 2230. Glucuronoxylan (14% wood weight) isolated by alkaline (KOH) or by dimethyl sulfoxide extraction was characterized by methylation analysis, 1H NMR, and GPC. About 10% of the xylopyranose (Xylp) units constituting the linear backbone were substituted at O-2 with 4-O-methylglucuronic acid residues. Almost half of the Xylp units (45%) were O-2 (18%), O-3 (24%) or O-2,3 (3%) acetylated. X-ray diffraction analysis of cellulose (46% wood weight), isolated according to the Kürschner-Hoffer method, showed a degree of crystallinity of 67.6%.
Pinto
Paula C
PC
CICECO and Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Evtuguin
Dmitry V
DV
Pascoal Neto
Carlos
C
D000045:Acacia / Q000737:chemistry*; D002482:Cellulose / Q000032:analysis / Q000737:chemistry; D008031:Lignin / Q000032:analysis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D009005:Monosaccharides / Q000032:analysis / Q000737:chemistry; D014934:Wood; D014990:Xylans / Q000032:analysis / Q000737:chemistry
D009005:Monosaccharides; D014990:Xylans; D002482:Cellulose; D008031:Lignin