Modeling Lignin Polymerization. I. Simulation Model of Dehydrogenation Polymers1[OA]

Lignin is a heteropolymer that is thought to form in the cell wall by combinatorial radical coupling of monolignols. Here, we present a simulation model of in vitro lignin polymerization, based on the combinatorial coupling theory, which allows us to predict the reaction conditions controlling the primary structure of lignin polymers. Our model predicts two controlling factors for the β-O-4 content of syringyl-guaiacyl lignins: the supply rate of monolignols and the relative amount of supplied sinapyl alcohol monomers. We have analyzed the in silico degradability of the resulting lignin polymers by cutting the resulting lignin polymers at β-O-4 bonds. These are cleaved in analytical methods used to study lignin composition, namely thioacidolysis and derivatization followed by reductive cleavage, under pulping conditions, and in some lignocellulosic biomass pretreatments.

[1]  John Ralph,et al.  Lignin engineering. , 2008, Current opinion in plant biology.

[2]  Leif A. Eriksson,et al.  Lignin Biosynthesis and Degradation - a Major Challenge for Computational Chemistry , 2002, VECPAR.

[3]  L. Lynd,et al.  Fuel Ethanol from Cellulosic Biomass , 1991, Science.

[4]  J. Ralph What Makes a Good Monolignol Substitute ? , 2007 .

[5]  John Ralph,et al.  The Effects on Lignin Structure of Overexpression of Ferulate 5-Hydroxylase in Hybrid Poplar1[W] , 2009, Plant Physiology.

[6]  R. Dixon,et al.  Lignification: are lignins biosynthesized via simple combinatorial chemistry or via proteinaceous control and template replication? , 2009 .

[7]  Vincent Danos,et al.  Internal coarse-graining of molecular systems , 2009, Proceedings of the National Academy of Sciences.

[8]  W. Glasser,et al.  Simulation of Reactions with Lignin by Computer (SIMREL). I. Polymerization of Coniferyl Alcohol Monomers , 1974 .

[9]  C. Lapierre,et al.  Thioacidolysis of Enzymatic Dehydrogenation Polymers from p-Hydroxyphenyl, Guaiacyl, and Syringyl Precursors , 1997 .

[10]  C. Lim,et al.  Dynamic Model of Lignin Growing in Restricted Spaces , 1995 .

[11]  Yi-ru Chen,et al.  Macromolecular replication during lignin biosynthesis. , 2010, Phytochemistry.

[12]  W. Vermerris,et al.  Lignin formation in plants. The dilemma of linkage specificity. , 2001, Plant physiology.

[13]  S. Polasky,et al.  Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels. , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[14]  L. Jurasek Toward a three-dimensional model of lignin structure , 1995 .

[15]  K. Freudenberg Beiträge zur Erforschung des Lignins , 1956 .

[16]  L. Landucci Reaction of p-Hydroxycinnamyl Alcohols with Transition Metal Salts 3. Preparation and NMR Characterization of Improved DHPs , 2000 .

[17]  B. Sundberg,et al.  Downregulation of Cinnamoyl-Coenzyme A Reductase in Poplar: Multiple-Level Phenotyping Reveals Effects on Cell Wall Polymer Metabolism and Structure[W] , 2007, The Plant Cell Online.

[18]  S. A. Ralph,et al.  New Preparations of Lignin Polymer Models under Conditions that Approximate Cell Wall Lignification. I. Synthesis of Novel Lignin Polymer Models and their Structural Characterization by 13 C NMR , 1995 .

[19]  K. Mazeau,et al.  The cellulose/lignin assembly assessed by molecular modeling. Part 2: Seeking for evidence of organization of lignin molecules at the interface with cellulose. , 2005, Plant physiology and biochemistry : PPB.

[20]  W. Boerjan,et al.  Lignin biosynthesis. , 2003, Annual review of plant biology.

[21]  John Ralph,et al.  Derivatization Followed by Reductive Cleavage (DFRC Method), a New Method for Lignin Analysis: Protocol for Analysis of DFRC Monomers , 1997 .

[22]  L. Jurasek Molecular modelling of fibre walls , 1998 .

[23]  L. Davin,et al.  Lignin primary structures and dirigent sites. , 2005, Current opinion in biotechnology.

[24]  L. Jouanin,et al.  Impact of CCR1 silencing on the assembly of lignified secondary walls in Arabidopsis thaliana. , 2009, The New phytologist.

[25]  W. Glasser,et al.  Simulation of Reactions with Lignin by Computer (SIMREL). 5. Nondehydrogenative Polymerization in Lignin Formation , 1976 .

[26]  J. Ralph,et al.  Apoplastic pH and monolignol addition rate effects on lignin formation and cell wall degradability in maize. , 2003, Journal of agricultural and food chemistry.

[27]  Richard A Dixon,et al.  Lignin modification improves fermentable sugar yields for biofuel production , 2007, Nature Biotechnology.

[28]  C. Chapple,et al.  Significant increases in pulping efficiency in C4H-F5H-transformed poplars: improved chemical savings and reduced environmental toxins. , 2003, Journal of agricultural and food chemistry.

[29]  Wout Boerjan,et al.  Lignin: genetic engineering and impact on pulping. , 2003, Critical reviews in biochemistry and molecular biology.

[30]  D. Gillespie Exact Stochastic Simulation of Coupled Chemical Reactions , 1977 .

[31]  Jørgen Holst Christensen,et al.  Lignins: Natural polymers from oxidative coupling of 4-hydroxyphenyl- propanoids , 2004, Phytochemistry Reviews.

[32]  T. E. Timell Compression Wood in Gymnosperms , 1986 .

[33]  Kaori Saito,et al.  Influence of syringyl to guaiacyl ratio on the structure of natural and synthetic lignins. , 2010, Journal of agricultural and food chemistry.

[34]  W. Boerjan,et al.  Field and pulping performances of transgenic trees with altered lignification , 2002, Nature Biotechnology.

[35]  S. Mansfield,et al.  The influence of lignin chemistry and ultrastructure on the pulping efficiency of clonal aspen (Populus tremuloides Michx.) , 2006 .

[36]  R. Custers First GM trial in Belgium since 2002 , 2009, Nature Biotechnology.

[37]  K. Mazeau,et al.  The cellulose/lignin assembly assessed by molecular modeling. Part 1: adsorption of a threo guaiacyl β-O-4 dimer onto a Iβ cellulose whisker , 2005 .

[38]  R. Atalla,et al.  Cellulose-Lignin Interactions (A Computational Study) , 1995, Plant physiology.

[39]  John Ralph,et al.  Profiling of Oligolignols Reveals Monolignol Coupling Conditions in Lignifying Poplar Xylem1[w] , 2004, Plant Physiology.

[40]  S. Dixit Studies in polymerization , 1969 .

[41]  M. Dewar,et al.  Studies in polymerization. I. A method for determining the velocity constants in polymerization reactions and its application to styrene , 1948, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.