This work describes the supported iron (III) porphyrin catalyzed biomimetic oxidation Of L-arginine with hydrogen peroxide. The result showed that the supported catalyst was efficient for the release of nitric oxide (NO.) and citrulline formation on the oxidation Of L-arginine with hydrogen peroxide. Alkyl peroxide such as tert-butyl hydroperoxide and cumene hydroperoxide were not effective oxygen donors in this catalytic reaction. Unsupported iron (III) porphyrin complex was not stable in the presence of peroxides and the porphyrin groups were oxidized with the separation of iron ions. To overcome this decomposition, anionic porphyrin complex was immobilized on a counter ionic resin matrix. The immobilized catalyst was characterized by powder X-ray diffraction, FT-IR analysis and diffuse reflectance UV-vis spectroscopy. This resin-supported iron (III) porphyrin catalyst was easily recovered after the reaction and reused without loss of activity. (c) 2006 Elsevier B.V. All rights reserved.