THE METABOLISM OF AZELAIC ACID* BY H. GREGG SMITHt

The evidence concerning the utilization of dibasic fatty acids in the animal organism has been reviewed by Dakin (3) and more recently by Flaschentrager (4). Oxalic acid is burned to a limited extent, and in large amounts is toxic. Malonic and succinic acids are utilized, and glutaric acid is completely oxidized in the dog (3), but is nephrotoxic to the rabbit, while the higher acids affect the rabbit kidney only slightly (7). Adipic acid is recovered in the urine of rabbits (5), dogs (4), and men (4) to the extent of 50 to 60 per cent of that injected or ingested. Flaschentriiger recovered 30 per cent of adipic, 60 per cent of suberic, and 61 per cent of sebacic acid from the urine of injected dogs. Baer and Blum (2) recovered from the urine of phlorhizinized dogs after injection of the acids: adipic, 12 per cent, pimelic, 47 per cent, suberic, 62 per cent, azelaic, 50 per cent, and sebacic, 45 and 13.6 per cent. The information concerning azelaic acid consists of the one experiment of Baer and Blum. In the naturally occurring unsaturated fatty acids the double bond nearest the carboxyl group is, with rare exceptions, in the 9:lO position. Oxidation of these acids with potassium permanganate yields, among other products, azelaic acid. If oxidation in viva in any way parallels that in vitro, azelaic acid should be formed in the body. The experiments described below demonstrate that approximately half the amount of azelaic acid fed to dogs can be recovered unchanged in the urine. The accumulat-