N-Formylation of an aromatic amine as a metabolic pathway.

1. Feeding 2-aminoanthraquinone (2-AAQ) in the diet to Fischer rats led to nephrotoxicity in females, caused by deposits of crystalline material in the kidney tubules. 2. This material consisted of 2-AAQ, N-acetyl-2-AAQ and N-formyl-2-AAQ. N-Formyl-2-AAQ was also identified in the ether extract of urine of rats fed 2-AAQ. 3. This represents the first case of identification of the N-formyl derivative of a primary aromatic amine as a metabolite in vivo.