Syringyl-type simple plant phenolics as mediating oxidants in laccase catalyzed degradation of lignocellulosic materials: Model compound studies

The utility of simple syringyl-type phenolics of plant origin and some common synthetic compounds were compared with regard to their ability to act as laccase mediators in the oxidation of non-phenolic lignin model compounds. It was demonstrated that syringyl-type phenols, especially acetosyringone and methyl syringate, were able to mediate the oxidation of substrates of high oxidation potential by a laccase with a low redox potential. A mediator dose around 10% showed good performance compared to the equimolar quantities needed when the synthetic compounds 1-hydroxybenzotriazole or N-hydroxyacetanilide were used.