Synthesis of polycardanol from a renewable resource using a fungal peroxidase from Coprinus cinereus

A fungal peroxidase from Coprinus cinereus (CiP) was successfully used for oxidative polymerization of cardanol in water–organic solvent mixtures. Cardanol is a phenol derivative from a renewable resource having the meta-substituent of a C15 unsaturated hydrocarbon chain mainly with one to three double bonds. So far, only uneconomic plant peroxidases, such as soybean peroxidase (SBP), have been used to polymerize cardanol. The fungal peroxidase used was easily produced by cultivating C. cinereus, and was purified by ultrafiltration and size exclusion chromatography. The purified peroxidase had a specific activity of 4960 U/mg. The CiP-catalyzed polymerization of cardanol was carried out in aqueous/organic solvents. Microbial CiP catalyzed the cardanol polymerization as efficiently as SBP. The structure and molecular weight of the polycardanol produced by CiP were comparable to those produced by SBP. A low reaction temperature of 10 and 15 °C produced polycardanol in high yield and the hydrogen peroxide feed rate was found to affect the initial reaction rate and the final conversion. From a practical point of view, it is believed that microbial CiP will be found more useful for the synthesis of a range of polyphenols from renewable resources than plant peroxidases.