Lignin Structure and Wood Properties

Authors

  • Heber dos Santos Abreu
  • Alexandre Miguel do Nascimento
  • Marcos Antônio Maria

Keywords:

Lignin, infrared, wood, methoxyl group, index of molecular flexibility (IMF), guaiacyl-glycerol-β-aryl ether (β-O-4)

Abstract

The objective of this study was to understand the relationship between lignin structural organization and certain wood properties. Lignin, which constitutes 20-30% of the weight of all woody plants, functions as a binding and encrusting material in the cell wall, giving rigidity to the overall plant structure. More than 60% of all linkages in lignins isolated (Björkman) from Aspidosperma macro-carpum, Lophanthera lactescens, Gallesia gorazema, Peltogyne paniculata, and Aspidosperma polyneuron were of the β-O-4 alkyl aryl ether type. This unit plays an important role in the physical and mechanical properties of wood. Percentages of β-O-4 unit were estimated by infrared spectroscopy. An Index of Molecular Flexibility (IMF) was introduced in order to hypothetically estimate the contribution of this unit toward wood flexibility, (under the assumption that the β-O-4 linkage is positively correlated with flexibility). Lignins from Aspidosperma macrocarpum (AM) and Aspidosperma poly-neuron (AP) show the highest and lowest structural complexity (diversity of linkage types β-β, β-5, β-O-4, etc.) with IMF values of 2.02 and 3.00, respectively. In this case, lignins AM and AP are supposedly contributing toward lowest and highest grade of wood flexibility, respectively, which demonstrates the hypothesis that β-O-4 linkages correlate well with flexibility.

References

Abreu, H. S. 1997 Estimativa por infravermelho da concentração da unidade estrutural β-O-4 em ligninas de angiospermas tropicais. QuíAmica nova 20(6):292-298.nBjörkman, A. 1956. Studies on finely divided wood. Sven. Papperstidn. 3:477-485.nCarpita, N. C., and D. M. Gibeaut. 1993. Structural models of primary cell walls in flowering plants: consistency of molecular structure with the physical properties of the wall during growth. The Plant Journal 3(1):1-30.nCassab, G. I., and E. J. Varner. 1988. Cell wall protein. Ann. Rev. Plant Physiol. Plant Mol. Biol. 39:321-353.nDavin, L. B., and N. G. Lewis. 1995. Lignin and lignan biochemical pathway in plant: An unprecedented discovery in phenolic coupling. An. Acad. bras. Ci. 67(supl. 3):364-378.nEraso, F., and R. D. Hartley. 1989. Monomeric and dimeric phenolic constituents of plant cell wall—possible factors influencing wall biodegradability. J. Sci. Food Agric. 51:163-170.nFaix, O., and O. Beinhoff. 1988. FTIR spectra of milled wood and lignin polymer models (DHP's) with enhanced resolution obtained by deconvolution. J. Wood Chem. Technol. 4:505-522.nFreudenberg, K., and A. C. Neish. 1968. Constitution and biosynthesis of lignins. Springer Verlag, Berlin, Germany. 123 pp.nFukuda, H. 1996. Xylogenesis: Initiation, progression and cell death. Ann. Rev. Plant Physiol. Plant Mol. Biol. 47: 299-325.nHahlbrock, K., and D. Scheel. 1989. Physiology and molecular biology of phenylpropanoid metabolism. Ann. Rev. Physiol. Plant Mol. Biol. 40:347-369.nHiguchi, T. 1985. Biosynthesis and biodegradation of wood components. Academic Press, New York, NY. 667 pp.nHiguchi, T., M. Shimada, F. Nakatsubo, and M. Tanahashi. 1977. Difference in biosyntheses of guaiacyl and syringyl lignin in wood. Wood Sci. Technol. 11:153-157.nHoutman, C. J., and R. H. Atalla. 1995. Cellulose-lignin interaction. Plant Physiol. 107:977-984.nLewis, N. G., and E. Yamamoto. 1990. Lignin: occurrence, biogenesis, and biodegradation. Ann. Rev. Plant Physiol. Plant Mol. Biol. 41:455-496.nLin, S. Y., and C. W. Dence. 1992. Methods in lignin chemistry. Springer Verlag, Berlin, Germany. 578 pp.nNose, M., M. A. Bernards, M. Furlan, J. Zajicek, T. Eberhardt, and N. G. Lewis. 1995. Toward the specification of consecutive steps in macromolecular lignin assembly. Phytochemistry 1:71-79.nSarkanen, K. V., and C. H. Ludwig. 1971. Lignins occurrence, formation, structure and reactions. Wiley-Interscience, New York, NY. 882 pp.nSimon, J. P., and K.-L. L. Eriksson. 1996. The significance of intra-molecular hydrogen bonding in the β-O-4 linkage of lignin. J. Macromolecules 384:1-7.nTerashima, N., R. H., and Atalla. 1995. Formation and structure of lignified plant cell wall—factors controlling lignin structure during its formation. Proc. 8th International Symposium on Wood and Pulping Chemistry, Helsinki, Finland 1:69-76.nTirumalai, V. C., U. P. Agarwal, and J. R. Obst. 1996. Heterogeneity of lignin concentration in cell corner middle lamella of white birch and black spruce. Wood Sci. Technol. 30:95-104.nVieböck, F. E., and B. Schwappach. 1930. Analytische methoden. Band II 63:2818. Houben-Weyl.nWhetten, R., and R. Sederoff. 1995. Lignin biosynthesis. The Plant Cell 7:1001-1013.n

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Published

2007-10-12

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Research Contributions