Degradation of a non-phenolic beta-O-4 substructure and of polymeric lignin model compounds by laccase of Coriolus versicolor in the presence of 1-hydroxybenzotriazole

A beta-O-4 lignin substructure model compound, 2-(2,6-dimethoxy-4-formylphe noxy)-1,3-dihydroxy-1-(4-ethoxy-3-methoxyphenyl)propane. was oxidized by Co riolus versicolor laccase in the presence of 1-hydroxybenzotriazole to form four products: 2,3-dihydroxy-1-(4-ethoxy-3-methoxyphenyl)propanone, 1-(4-e thoxy-3-methoxyphenyl)-3-hydloxypropanone. 4-ethoxy-3-methoxybenzoic acid, and 2,6-dimethoxy-p-benzoquinone. The results show that three types of the reactions, beta-ether cleavage, C alpha-C beta cleavage, and C alpha-oxidat ion are catalyzed by laccase-1-hydroxybenzotriazole couple. Furthermore, de polymerization of a polymeric guaiacyl lignin model compound prepared from [beta-C-14]coniferyl alcohol was also caused by this system. (C) 1999 Feder ation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.