title: The synthesis and analysis of lignin-bound Hibbert ketone structures in technical lignins.
abstract: Understanding the structure of technical lignins resulting from acid-catalysed treatment of lignocellulosic biomass is important for their future applications. Here we report an investigation into the fate of lignin under acidic aqueous organosolv conditions. In particular we examine in detail the formation and reactivity of non-native Hibbert ketone structures found in isolated organosolv lignins from both Douglas fir and beech woods. Through the use of model compounds combined with HSQC, HMBC and HSQC-TOCSY NMR experiments we demonstrate that, depending on the lignin source, both S and G lignin-bound Hibbert ketone units can be present. We also show that these units can serve as a source of novel mono-aromatic compounds following an additional lignin depolymerisation reaction.
authors.affiliation: School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, KY16 9ST, UK. njw3@st-andrews.ac.uk.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Miles-Barrett
authors.affiliation: School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, KY16 9ST, UK. njw3@st-andrews.ac.uk.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Neal
authors.affiliation: School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, KY16 9ST, UK. njw3@st-andrews.ac.uk.
authors.forename: Calum
authors.initials: C
authors.lastname: Hand
authors.affiliation: School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, KY16 9ST, UK. njw3@st-andrews.ac.uk.
authors.forename: James R D
authors.initials: JR
authors.lastname: Montgomery
authors.affiliation: School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, KY16 9ST, UK. njw3@st-andrews.ac.uk.
authors.forename: Isabella
authors.initials: I
authors.lastname: Panovic
authors.affiliation: School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, KY16 9ST, UK. njw3@st-andrews.ac.uk.
authors.forename: O Stephen
authors.initials: OS
authors.lastname: Ojo
authors.affiliation: School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, KY16 9ST, UK. njw3@st-andrews.ac.uk.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Lancefield
authors.affiliation: School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, KY16 9ST, UK. njw3@st-andrews.ac.uk.
authors.forename: David B
authors.identifier: http://orcid.org/0000-0002-5366-9168
authors.initials: DB
authors.lastname: Cordes
authors.affiliation: School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, KY16 9ST, UK. njw3@st-andrews.ac.uk.
authors.forename: Alexandra M Z
authors.initials: AM
authors.lastname: Slawin
authors.affiliation: School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, KY16 9ST, UK. njw3@st-andrews.ac.uk.
authors.forename: Tomas
authors.initials: T
authors.lastname: Lebl
authors.affiliation: School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, KY16 9ST, UK. njw3@st-andrews.ac.uk.
authors.forename: Nicholas J
authors.identifier: http://orcid.org/0000-0003-0630-0138
authors.initials: NJ
authors.lastname: Westwood
mesh_terms: D060326:Chemistry Techniques, Synthetic; D006863:Hydrogen-Ion Concentration; D007659:Ketones / Q000737:chemistry*; D008031:Lignin / Q000138:chemical synthesis* / Q000737:chemistry*; D014934:Wood / Q000737:chemistry
chemical_list: D007659:Ketones; D008031:Lignin