The early oxidative biodegradation steps of residual kraft lignin models with laccase
作者:Claudia Crestini、Dimitris S. Argyropoulos
DOI:10.1016/s0968-0896(98)00173-4
日期:1998.11
A number of model compounds resembling the fundamental bonding patterns of residual kraft lignin, including a series of stilbenes, were incubated with laccase from Trametes versicolor in the presence and absence of delignification 'mediators' ABTS and HBT. The condensed kraft lignin model compounds seem to undergo initial degradation by laccase mainly via benzylic oxidation, demethylation and hydroxylation reactions. Phenolic 5-5', diphenylmethane and alpha-5 lignin models were found to be degraded mainly via side-chain oxidation reactions. Among the models studied, a phenolic stilbene was found to be the most reactive, yielding several products showing side-chain oxidation/transposition, demethoxylation and hydroxylation reactions. Non-phenolic 5-5', diphenylmethane and stilbene model compounds were found unreactive even in the presence of the laccase-mediator system. (C) 1998 Elsevier Science Ltd. All rights reserved.
The reactivity of phenolic and non-phenolic residual kraft lignin model compounds with Mn(II)-peroxidase from Lentinula edodes
Three phenolic model compounds representing bonding patterns of residual kraft lignin were incubated with manganese peroxidase from Lentinula edodes. Extensive degradation of all the phenolic models, mainly occurring via side-chain benzylic oxidation, was observed. Among the tested model compounds the diphenylmethane alpha-5 phenolic model was found to be the most reactive, yielding several products showing oxidation and fragmentation at the bridging position. The non-phenolic 5-5' biphenyl and 5-5' diphenylmethane models were found unreactive. (C) 2000 Elsevier Science Ltd. All rights reserved.
PROCÉDÉ DE PRÉPARATION D'UN DÉRIVÉ DE VANILLINE
申请人:Rhodia Operations
公开号:EP2763947B1
公开(公告)日:2016-02-10
NATURAL VANILLIN COMPOSITIONS
申请人:RHODIA OPERATIONS
公开号:US20220264922A1
公开(公告)日:2022-08-25
The present invention relates to natural vanillin compositions comprising at least one compound chosen from 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde and 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde. The invention also relates to a process for obtaining natural vanillin compositions according to the invention.