Peroxidases (PODs) from radish (Raphanus sativus L.) and turnip (Brassica napus L.) were extracted and precipitated with ammonium sulfate using a simple, low cost and quick method. The activities of all steps performed by the vegetable PODs were measured via guaiacol assay. The epoxidation of isosafrol, catalyzed by radish (R. sativus L.) and turnip (B. napus L.) peroxidases was conducted in 20% (v/v) aqueous ethanol solution using 30% (v/v) H2O2 as the terminal oxidant. High conversion (88%) and selectivity (>98%) were obtained after 48 h. The products of the reaction were analyzed by high resolution gas chromatography (GC) and mass spectrometry.
Key words: Raphanus sativus L, Brassica napus L., peroxidase, epoxidation, isosafrol.
HRP, Horseradish peroxidase; GC, gas chromatography; POD, peroxidases.