Reactions of hemoglobin with phenylhydrazine: a review of selected aspects.

It is well known that phenylhydrazine induces hemolytic anemia. This is thought to result from the reaction of phenylhydrazine with hemoglobin. The accompanying oxidation of phenylhydrazine leads to the formation of a number of products, including benzene, nitrogen, hydrogen peroxide, superoxide anion and the phenyl radical. The products formed depend critically on the conditions of the experiment, especially the amount of oxygen present. It is now known that oxyhemoglobin and myoglobin react with phenylhydrazine to yield a derivative of hemoglobin containing N-phenylprotoporphyrin in which the heme group is modified. The recent identification of sigma-phenyliron(III) porphyrins in phenylhydrazine-modified metmyoglobin has aided elucidation of the mechanism of hemoglobin modification. Mechanistic schemes are proposed to account for product formation.