title: Structural transformation of hemicelluloses and lignin from triploid poplar during acid-pretreatment based biorefinery process.
abstract: In order to understand the behaviors of hemicelluloses and lignin under the given acidic conditions with increasing severity, the structural characteristics were elucidated in detail by both wet chemistry methods and spectroscopic analyses in this study. Although acidic pretreatment significantly hydrolyzed the glycosidic linkages in xylan backbone and then reduced the molecular weight of xylan from 89,600 to 19,630 g/mol, a slightly increased amount of glucuronic acid was observed, probably attributing to the maintenance of ester bonds. The serious structural variation occurred in lignin macromolecule was evidenced by the extensive degradation of β-O-4 ether linkages and resinol substructure, together with the changes in the ratios of the three monolignols in ester-bond, ether-bond and non-condensed phenolic compounds. At the most severity, obvious condensation reactions introduced the clear shift of C(2) and C(5) correlations and the absence of C(6) correlation in guaiacyl units by 2D HSQC analysis.
authors.affiliation: Institute of Biomass Chemistry and Technology, Beijing Forestry University, Beijing 100083, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.forename: Haiyan
authors.initials: H
authors.lastname: Yang
authors.forename: Xi
authors.initials: X
authors.lastname: Yao
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.forename: Run-Cang
authors.initials: RC
authors.lastname: Sun
mesh_terms: D000447:Aldehydes / Q000032:analysis; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D002473:Cell Wall / Q000737:chemistry / Q000187:drug effects; D005591:Chemical Fractionation; D062385:Hydroxybenzoates / Q000032:analysis; D008031:Lignin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D010636:Phenols / Q000032:analysis; D011134:Polysaccharides / Q000737:chemistry*; D032107:Populus / Q000187:drug effects*; D013464:Sulfuric Acids / Q000494:pharmacology*; D057885:Triploidy
chemical_list: D000447:Aldehydes; D062385:Hydroxybenzoates; D010636:Phenols; D011134:Polysaccharides; D013464:Sulfuric Acids; C007916:hemicellulose; D008031:Lignin; C017616:phenolic acid; C033158:sulfuric acid