title: Lignin-Derived Thioacidolysis Dimers: Reevaluation, New Products, Authentication, and Quantification.
abstract: Lignin structural studies play an essential role both in understanding the development of plant cell walls and for valorizing lignocellulosics as renewable biomaterials. Dimeric products released by selectively cleaving β-aryl ether linkages between lignin units reflect the distribution of recalcitrant lignin units, but have been neither absolutely defined nor quantitatively determined. Here, 12 guaiacyl-type thioacidolysis dimers were identified and quantified using newly synthesized standards. One product previously attributed to deriving from β-1-coupled units was established as resulting from β-5 units, correcting an analytical quandary. Another longstanding dilemma, that no β-β dimers were recognized in thioacidolysis products from gymnosperms, was resolved with the discovery of two such authenticated compounds. Individual GC response factors for each standard compound allowed rigorous quantification of dimeric products released from softwood lignins, affording insight into the various interunit-linkage distributions in lignins and thereby guiding the valorization of lignocellulosics.
authors.affiliation: State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 381 Wushan Rd, Tianhe District, Guangzhou, 510640, P. R. China.|Department of Biochemistry and DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, 1552 University Ave., Madison, WI, 53726, USA.
authors.forename: Fengxia
authors.identifier: 0000-0002-5203-2421
authors.initials: F
authors.lastname: Yue
authors.affiliation: State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 381 Wushan Rd, Tianhe District, Guangzhou, 510640, P. R. China.|Department of Biochemistry and DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, 1552 University Ave., Madison, WI, 53726, USA.
authors.forename: Fachuang
authors.identifier: 0000-0002-8230-9129
authors.initials: F
authors.lastname: Lu
authors.affiliation: Department of Biochemistry and DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, 1552 University Ave., Madison, WI, 53726, USA.
authors.forename: Matt
authors.identifier: 0000-0001-7799-2704
authors.initials: M
authors.lastname: Regner
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, 35 Qinghua East Rd, Haidian District, Beijing, 100083, P. R. China.
authors.forename: Runcang
authors.identifier: 0000-0001-8972-9559
authors.initials: R
authors.lastname: Sun
authors.affiliation: Department of Biochemistry and DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, 1552 University Ave., Madison, WI, 53726, USA.
authors.forename: John
authors.identifier: 0000-0002-6093-4521
authors.initials: J
authors.lastname: Ralph
mesh_terms: D019281:Dimerization; D006863:Hydrogen-Ion Concentration; D008031:Lignin / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry*; D014934:Wood / Q000737:chemistry
chemical_list: D013455:Sulfur; D008031:Lignin
keywords: GC-FID; analytical methods; lignin dimers; response factor; synthesis design