Oxidation of l-arginine to citrulline and nitrate induced by photoexcitation of an iron–porphyrin cysteinate complex

The conversion of l-arginine to citrulline together with the oxidation of l-cysteine to cysteine sulphinate are obtained by irradiation with near UV light of an iron–porphyrin in aqueous solution in the presence of l-cysteine which appears to be necessary for the process to occur; the NO3 − detection indicates that NO is formed and allows one to conclude that the reaction mechanism presents interesting analogies with that of the in vivo production of NO.