title: Horseradish peroxidase-catalyzed polymerization of cardanol in the presence of redox mediators.
abstract: Horseradish peroxidase-catalyzed polymerization of cardanol in aqueous organic solvent was investigated in the presence of a redox mediator. Cardanol is a phenol derivative from a renewable resource mainly having a C15 unsaturated hydrocarbon chain with mostly 1-3 double bonds at a meta position. Unlike soybean peroxidase (SBP), it has been shown that horseradish peroxidase (HRP) is not able to perform oxidative polymerization of phenol derivatives having a bulky meta substituent such as cardanol. For the first time, redox mediators have been applied to enable horseradish peroxidase to polymerize cardanol. Veratryl alcohol, N-ethyl phenothiazine, and phenothiazine-10-propionic acid were tested as a mediator. It is surprising that the horseradish peroxidase-catalyzed polymerization of cardanol took place in the presence of N-ethyl phenothiazine or phenothiazine-10-propionic acid. However, veratryl alcohol showed no effect. FT-IR and GPC analysis of the product revealed that the structure and properties of polycardanol formed by HRP with a mediator were similar to those by SBP. This is the first work to apply a redox mediator to enzyme-catalyzed oxidative polymerization. Our new finding that oxidative polymerization of a poor substrate, which the enzyme is not active with, can take place in the presence of an appropriate mediator will present more opportunities for the application of enzyme-catalyzed polymerization.
authors.affiliation: Korea Research Institute of Chemical Technology, 100 Jang-Dong, Yuseong-Gu, Daejeon 305-343, South Korea.
authors.forename: Keehoon
authors.initials: K
authors.lastname: Won
authors.forename: Yong Hwan
authors.initials: YH
authors.lastname: Kim
authors.forename: Eun Suk
authors.initials: ES
authors.lastname: An
authors.forename: Yeon Soo
authors.initials: YS
authors.lastname: Lee
authors.forename: Bong Keun
authors.initials: BK
authors.lastname: Song
mesh_terms: D002384:Catalysis; D006735:Horseradish Peroxidase; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D010936:Plant Extracts; D011108:Polymers / Q000138:chemical synthesis*
chemical_list: D010636:Phenols; D010936:Plant Extracts; D011108:Polymers; C038590:cardanol; D006735:Horseradish Peroxidase