title: Occurrence of naturally acetylated lignin units.
abstract: This work examines the occurrence of native acetylated lignin in a large set of vascular plants, including both angiosperms and gymnosperms, by a modification of the so-called Derivatization Followed by Reductive Cleavage (DFRC) method. Acetylated lignin units were found in the milled wood lignins of all angiosperms selected for this study, including mono- and eudicotyledons, but were absent in the gymnosperms analyzed. In some plants (e.g., abaca, sisal, kenaf, or hornbeam), lignin acetylation occurred at a very high extent, exceeding 45% of the uncondensed (alkyl-aryl ether linked) syringyl lignin units. Acetylation was observed exclusively at the gamma-carbon of the lignin side chain and predominantly on syringyl units, although a predominance of acetylated guaiacyl over syringyl units was observed in some plants. In all cases, acetylation appears to occur at the monomer stage, and sinapyl and coniferyl acetates seem to behave as real lignin monomers participating in lignification.
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, P.O. Box 1052, 41080 Seville, Spain. delrio@irnase.csic.es
authors.forename: José C
authors.initials: JC
authors.lastname: Del Río
authors.forename: Gisela
authors.initials: G
authors.lastname: Marques
authors.forename: Jorge
authors.initials: J
authors.lastname: Rencoret
authors.forename: Angel T
authors.initials: AT
authors.lastname: Martínez
authors.forename: Ana
authors.initials: A
authors.lastname: Gutiérrez
mesh_terms: D000107:Acetylation; D032462:Cycadopsida / Q000737:chemistry; D008031:Lignin / Q000032:analysis* / Q000737:chemistry*; D019684:Magnoliopsida / Q000737:chemistry; D010944:Plants / Q000737:chemistry*; D014934:Wood / Q000737:chemistry
chemical_list: D008031:Lignin