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

Abstract

The deacylation of N-formylanilines and Nacetylanilines to aniline derivatives was examined in rat liver preparations. When N 4 -formylsulfanilamide or N 4 -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. N 4 -Formylsulfanilamide and N 4 -acetylsulfanilamide were deacylated by formamidase purified from rat liver cytosol. N-Acetyl-or Nformylanilines 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 Nformyl-L-kynurenine. Formamidase catalyzed both Nformylation of aniline derivatives, and deacylation of N-formylanilines and N-acetylanilines.