Supramolecular Interactions in Secondary Plant Cell Walls: Effect of Lignin Chemical Composition Revealed with the Molecular Theory of Solvation

Author(s)

Silveira, Rodrigo L. ^{[1, 2]} ; Stoyanov, Stanislav R. ^{[2, 3, 4]} ; Gusarov, Sergey ^[2] ; Skaf, Munir S. ^[1] ; Kovalenko, Andriy ^{[2, 3]}

Affiliation

^[1] Univ Estadual Campinas, Inst Chem, BR-13083970 Sao Paulo - Brazil

^[2] Natl Inst Nanotechnol, Edmonton, AB T6G 2M9 - Canada

^[3] Univ Alberta, Dept Chem & Mat Engn, Edmonton, AB T6G 2V4 - Canada

^[4] Univ Alberta, Dept Mech Engn, Edmonton, AB T6G 2G8 - Canada

• Document type: Journal article
• Source: Journal of Physical Chemistry Letters; v. 6, n. 1, p. 206-211, JAN 1 2015.
• Web of Science Citations: 28

Abstract

Plant biomass recalcitrance, a major obstacle to achieving sustainable production of second generation biofiiels, arises mainly from the amorphous cell-wall matrix containing lignin and hemicellulose assembled into a complex supramolecular network that coats the cellulose fibrils. We employed the statistical-mechanical, 3D reference interaction site model with the Kovalenko-Hirata closure approximation (or 3D-RISM-KH molecular theory of solvation) to reveal the supramolecular interactions in this network and provide molecular-level insight into the effective lignin-lignin and lignin-hemicellulose thermodynamic interactions. We found that such interactions are hydrophobic and entropy-driven, and arise from the expelling of water from the mutual interaction surfaces. The molecular origin of these interactions is carbohydrate-pi and pi-pi stacking forces, whose strengths are dependent on the lignin chemical composition. Methoxy substituents in the phenyl groups of lignin promote substantial entropic stabilization of the ligno-hemicellulosic matrix. Our results provide a detailed molecular view of the fundamental interactions within the secondary plant cell walls that lead to recalcitrance. (AU)

• FAPESP's process: 13/08293-7 - CCES - Center for Computational Engineering and Sciences
• Grantee: Munir Salomao Skaf
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 14/10448-1 - Molecular aspects of plant cell wall architecture
• Grantee: Rodrigo Leandro Silveira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral