Cellulose-Lignin Interactions (A Computational Study).
Within a broader program of study of the molecular structure of plant cell walls, molecular dynamics calculations were used to explore the character of the motion of lignin model compounds near a cellulose surface. Model cellulose microfibrils, which have a large number of hydroxyl groups on the surface, appear to have a net attractive interaction with the lignin models examined in this study. The lignin monomer coniferyl alcohol rapidly adsorbed onto the surface from a water layer after it was released 13 A from the surface. The major long-range force responsible for this adsorption is likely electrostatic. The attractive interaction is sufficient to restrict the motion of coniferyl alcohol when it is within 1 A of the surface and to orient the phenyl ring parallel to the surface. The [beta]-O-4-linked trimer also was observed to adsorb onto the surface with two of its phenyl rings parallel to the surface. These results suggest a mechanism by which the polysaccharide component of the plant cell wall could influence the structure of lignin. Furthermore, they provide a rationalization of the experimental observation that polysaccharides can change the course of dehydrogenation polymerization of cinnamyl alcohols.
Houtman
C. J.
CJ
United States Department of Agriculture, Forest Service, Forest Product Laboratory, One Gifford Pinchot Drive, Madison, Wisconsin 53705.
Atalla
R. H.
RH