Dimeric lignin models

Various authors have also described the reduction of dimeric lignin model structures both aromatic aldehydes and aromatic acids were reduced by ligninolytic cultures of P. chrysosporium, sis shown by the reduction of the 0-0-4 model 1 (acid, lacking the C7-substituent) to the corresponding alcohol 2 (24) and the phenyl coumaran models 3 (acid) and 4 (aldehyde) to the corresponding alcohol 5 (25). 

In this section, examples of information available from ozonation of lignin model compounds, related compounds, and lignins will be presented. Table 6.7.2 lists the monomeric and dimeric lignin model compounds that have been ozonated. 

Dimeric Lignin Model Compounds The P-0-4 model compound, guaiacylglyc-erol-P-guaiacyl ether (Ha), was relatively stable to peracetic acid at pH 7 [79]. The saturated phenyl coumarans, dihydro-dehydro-di-iioeugenol and its methyl... 

Miki K., Renganathan V., Gold M.H. (1986) Mechanism of (3-aryl ether dimeric lignin model compound oxidation by lignin peroxidase of Phanerochaete chrysosporium. Biochemistry 25, 4790-6. 

Besides the lignin thermolysis products with a known structaire. Table 2 contains nine dimeric lignin model compounds (6, 8, 9, 14—17, 20,23) and some colored thermolysis products of unknown structure. 

Letumier F, Barbe J-M, Trichet A, Grulard R (1999) Ozonation reactions of monomer and dimer lignin models influence of a catalytic amount of a manganese cyclam derivaties on the ozonation reaction. Ozone Science Engineering - The Journal of the International Ozone Association 21 53-67... 

The mechanism of the pyrolysis of phenethyl phenyl ether as dimeric lignin model compounds has been studied by DFT methods at B3LYP/6-31G(d) level. Ten possible pyrolytic pathways were proposed including two concerted reactions and eight free-radical reactions. The calculation results show that all reactions are endothermic. The... 

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