title: Effects of a biologically relevant antioxidant on the dehydrogenative polymerization of coniferyl alcohol.
abstract: Dehydrogenation polymers (DHPs or synthetic lignins) were synthesized from coniferyl alcohol by enzymatic oxidation in the presence of ascorbic acid to study the potential effects of an antioxidant upon their structure. Specific interunit substructures (beta-O-4', beta-beta', and beta-5') were quantified by 13C NMR, which showed how ascorbic acid altered their amounts compared with control syntheses without this antioxidant, especially by increasing the amount of beta-O-4' substructures. The effect of ascorbic acid increased with its concentration. Surprisingly, no influence on the sizes of the synthetic lignins, as determined by size exclusion chromatography, was observed. The chemistry of this antioxidant effect during dehydrogenative polymerization and the potential biological significance (cell wall lignification) of these observations are discussed.
authors.affiliation: Division of Wood Chemistry and Pulp Technology, Department of Fibre and Polymer Technology, Royal Institute of Technology, KTH, 10044 Stockholm, Sweden. anders8@kth.se
authors.forename: Anders
authors.initials: A
authors.lastname: Holmgren
authors.forename: Gunnar
authors.initials: G
authors.lastname: Henriksson
authors.forename: Liming
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D001205:Ascorbic Acid / Q000737:chemistry*; D002850:Chromatography, Gel; D006735:Horseradish Peroxidase / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008031:Lignin / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D015394:Molecular Structure; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D010636:Phenols; D008031:Lignin; D006861:Hydrogen Peroxide; C010559:coniferyl alcohol; D006735:Horseradish Peroxidase; D001205:Ascorbic Acid