Deacylation of N-Formylanilines and N-Acetylanilines by Rat Liver Formamidase

Abstract

The deacylation of N-formylanilines and N-acetylanilines to aniline derivatives was examined in rat liver preparations. When N⁴-formylsulfanilamide or N⁴-acetylsulfanilamide was incubated with rat liver cytosol, the deacylated metabolite, sulfanilamide, was formed. These deacylating activities were inhibited by paraoxone and diisopropyl fluorophosphate, inhibitors of formamidase. N⁴-Formylsulfanilamide and N⁴-acetylsulfanilamide were deacylated by formamidase purified from rat liver cytosol. N-Acetyl- or N-formylanilines bearing an electron-withdrawing group at the para position were deacylated to anilines by formamidase. In contrast, anilines bearing an electron-donating group at the para position were formylated to N-formylanilines in the presence of N-formyl-L-kynurenine. Formamidase catalyzed both N-formylation of aniline derivatives, and deacylation of N-formylanilines and N-acetylanilines.