Enzymic rupture of a C—F bond

There is as yet no known enzyme that breaks the C—F bond in fluoroacetic acid, FCHgCOOH, or in related compounds. It is interesting to note, however, that in the course of our investiga-tions on peroxidase-catalysed oxidations, we have effected an enzymic cleavage of the C—bond in p-fluoroaniline. In acetate buffer (pH 4-5) and at room temperature, the amine was oxidized by hydrogen peroxide and peroxidase to give mainly the red crystalline 2-aminO 5-p fluoroanilinobenzoquinone di-p-fluoroanil (XX). 

The formation of (XX) requires the elimination of one fluorine atom per four molecules of amine. The fluorine was expelled as F, and since the enzyme reaction is retarded by F, the process is self poisoning. As might have been expected the reaction was not complete it stopped at 30 per cent completion and F was detected on the walls of the containing vessel. 

It is beheved that the oxidation of p-fluoroaniline is the first recorded case of an enzymic cleavage of a C—F bond. 

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