Metabolism of drugs. LXXX. The metabolic fate of nitrofuran derivatives. 3. Studies on enzymes in small intestinal mucosa of rat catalyzing degradation of nitrofuran derivatives.

The enzymes responsible for the degradation of nitrofuran derivatives in rat small intestinal mucosa were examined in vitro.As a result,it was suggested that the initial reactions in the degradation of 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide(AF-2) and 5-nitro-2-furfural semicarbazone(nitrofurazone)are mainly catalyzed by xanthine oxidase , while that of 2-amino-5-[2-(5-nitro-2-fury1)-1-(2-furyl)viny1]-1,3 ,4-oxadiazole(NF-161)is catalyzed by alternative enzyme beside xanthine oxidase,too. Furthermore,the present results suggest that a part of metabolites formed from AF-2 by hypoxanthine-dependent or NADH-dependent reaction in rat small intestinal mucosa might be tightly bound to or physically adsorbed to the macromolecules of cellular constituents.