86370-40-3Relevant academic research and scientific papers
METHOD OF SELECTIVELY OXIDIZING LIGNIN
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Paragraph 0037; 0038, (2019/06/20)
A method of selectively reacting lignin or a lignin-derived reactant to yield an aromatic product. The method includes the step of reacting lignin or a lignin-derived reactant with a molybdenum-containing catalyst, in a solvent, and optionally in the presence of an oxidant, for a time and a temperature wherein at least a portion of the lignin or lignin-derived reactant is selectively converted into an aromatic product, preferably coniferaldehyde and/or sinapaldehyde.
Non-enzymatic reduction of quinone methides during oxidative coupling of monolignols: Implications for the origin of benzyl structures in lignins
Holmgren, Anders,Brunow, Goesta,Henriksson, Gunnar,Zhang, Liming,Ralph, John
, p. 3456 - 3461 (2008/09/16)
Lignin is believed to be synthesized by oxidative coupling of 4-hydroxyphenylpropanoids. In native lignin there are some types of reduced structures that cannot be explained solely by oxidative coupling. In the present work we showed via biomimetic model experiments that nicotinamide adenine dinucleotide (NADH), in an uncatalyzed process, reduced a β-aryl ether quinone methide to its benzyl derivative. A number of other biologically significant reductants, including the enzyme cellobiose dehydrogenase, failed to produce the reduced structures. Synthetic dehydrogenation polymers of coniferyl alcohol synthesized (under oxidative conditions) in the presence of the reductant NADH produced the same kind of reduced structures as in the model experiment, demonstrating that oxidative and reductive processes can occur in the same environment, and that reduction of the in situ-generated quinone methides was sufficiently competitive with water addition. In situ reduction of β-β-quinone methides was not achieved in this study. The origin of racemic benzyl structures in lignins therefore remains unknown, but the potential for simple chemical reduction is demonstrated here. The Royal Society of Chemistry 2006.
The incorporation of 3,4-dichloroaniline, a pesticide metabolite, into dehydrogenation polymers of coniferyl alcohol (DHPs)
Brunow, Goesta,Raiskila, Sanni,Sipilae, Jussi
, p. 1338 - 1342 (2007/10/03)
A mechanism by which pesticide metabolites may become incorporated into plant lignins has been studied with the aid of 3,4-dichloroaniline (DCA) and lignin model compounds. DCA was found to react rapidly with a quinone methide representing an intermediate in lignin biosynthesis. The resulting benzylamine group was stable to mild acidolysis under simulated stomach conditions. Addition of DCA to dehydrogenative polymerizations of coniferyl alcohol yielded DHPs containing covalently bonded DCA. NMR spectroscopy showed that the DCA had become bonded to the benzylic position in arylglycerol-β-guaiacyl ether structures. The majority of these structures were phenolic. This observation and the fact that the DCA accumulates in the low molecular weight fraction of the DHP indicates that the DCA functions as a trap for quinone methides and stops the further growth of the polymer. Acta Chemica Scandinavica 1998.
