title: Structural variation of bamboo lignin before and after ethanol organosolv pretreatment.
abstract: In order to make better use of lignocellulosic biomass for the production of renewable fuels and chemicals, it is necessary to disrupt its recalcitrant structure through pretreatment. Specifically, organosolv pretreatment is a feasible method. The main advantage of this method compared to other lignocellulosic pretreatment technologies is the extraction of high-quality lignin for the production of value-added products. In this study, bamboo was treated in a batch reactor with 70% ethanol at 180 °C for 2 h. Lignin fractions were isolated from the hydrolysate by centrifugation and then precipitated as ethanol organosolv lignin. Two types of milled wood lignins (MWLs) were isolated from the raw bamboo and the organosolv pretreated residue separately. After the pretreatment, a decrease of lignin (preferentially guaiacyl unit), hemicelluloses and less ordered cellulose was detected in the bamboo material. It was confirmed that the bamboo MWL is of HGS type (p-hydroxyphenyl (H), vanillin (G), syringaldehyde (S)) associated with a considerable amount of p-coumarate and ferulic esters of lignin. The ethanol organosolv treatment was shown to remove significant amounts of lignin and hemicelluloses without strongly affecting lignin primary structure and its lignin functional groups.
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China. rcsun3@bjfu.edu.cn.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Bai
authors.forename: Ling-Ping
authors.initials: LP
authors.lastname: Xiao
authors.forename: Zheng-Jun
authors.initials: ZJ
authors.lastname: Shi
authors.forename: Run-Cang
authors.initials: RC
authors.lastname: Sun
mesh_terms: D018533:Biomass; D000431:Ethanol / Q000737:chemistry* / Q000494:pharmacology; D006026:Glycoside Hydrolases / Q000737:chemistry; D008031:Lignin / Q000737:chemistry* / Q000302:isolation & purification; D019906:Nuclear Magnetic Resonance, Biomolecular; D031787:Sasa / Q000187:drug effects
chemical_list: C036909:lignocellulose; D000431:Ethanol; D008031:Lignin; D006026:Glycoside Hydrolases; C023305:hemicellulase