title: Unraveling the Structural Modifications in Lignin of Arundo donax Linn. during Acid-Enhanced Ionic Liquid Pretreatment.
abstract: Solid acid-enhanced ionic liquid (IL) pretreatment is of paramount importance for boosting the yield of sugars from biomass cost-effectively and environmentally friendly. To unravel the chemical and supramolecular structural changes of lignin after pretreatment, IL-acid lignin (ILAL) and subsequent residual cellulolytic enzyme lignin (RCEL) were isolated from Arundo donax Linn. The structural features were compared with those of the corresponding milled wood lignin (MWL). Results indicated that the pretreatment caused loss of β-O-4', β-β', β-1' linkages and formation of condensed structures in lignin. A preferential breakdown of G-type lignin may have occurred, evidenced by an increased S/G ratio revealed by 2D HSQC NMR analysis. It was determined that the depolymerization of β-O-4' linkage, lignin recondensation, and cleavage of ferulate-lignin ether linkages took place. Moreover, a simulation module was first developed to define morphological changes in lignin based on AFM and TEM analyses. Briefly, tree branch like aggregates was destroyed to monodisperse particles.
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University , Beijing, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: You
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University , Beijing, China.
authors.forename: Liming
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University , Beijing, China.
authors.forename: Siqin
authors.initials: S
authors.lastname: Guo
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University , Beijing, China.
authors.forename: Lupeng
authors.initials: L
authors.lastname: Shao
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University , Beijing, China.|Key Laboratory of Pulp and Paper Science and Technology, Ministry of Education, Qilu University of Technology , Shandong, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
mesh_terms: D000143:Acids; D018533:Biomass; D002236:Carbohydrate Conformation / Q000187:drug effects; D003373:Coumaric Acids / Q000737:chemistry; D007093:Imidazoles; D052578:Ionic Liquids / Q000494:pharmacology*; D008031:Lignin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D008970:Molecular Weight; D006109:Poaceae / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014934:Wood / Q000737:chemistry
chemical_list: C525963:1-butyl-3-methylimidazolium; D000143:Acids; D003373:Coumaric Acids; D007093:Imidazoles; D052578:Ionic Liquids; D008031:Lignin; C004999:ferulic acid
keywords: Arundo donax Linn.; IL−acid pretreatment; lignin; structure modification