Degradation of the γ-Carboxyl-Containing Diarylpropane Lignin Model Compound 3-(4′-Ethoxy-3′-Methoxyphenyl)-2-(4″-Methoxyphenyl)Propionic Acid by the Basidiomycete Phanerochaete chrysosporium

摘要

The white-rot basidiomycete Phanerochaete chrysosporium metabolized 3-(4′-ethoxy-3′-methoxyphenyl)-2-(4″-methoxyphenyl)propionic acid (V) in low-nitrogen, stationary cultures, conditions under which ligninolytic activity is expressed. The ability of several fungal mutant strains to degrade V reflected their ability to degrade [¹⁴C]lignin to ¹⁴CO2. 1-(4′-Ethoxy-3′-methoxyphenyl)-2-(4″-methoxyphenyl)-2- hydroxyethane (VII), anisyl alcohol, and 4-ethoxy-3-methoxybenzyl alcohol were isolated as metabolic products, indicating an initial oxidative decarboxylation of V, followed by α, β cleavage of the intermediate (VII). Exogenously added VII was rapidly converted to anisyl alcohol and 4-ethoxy-3-methoxybenzyl alcohol. When the degradation of V was carried out under ¹⁸O2, ¹⁸O was incorporated into the β position of the diarylethane product (VII), indicating that the reaction is oxygenative.