Oxidative metabolites of 5-nitrofurans.

We synthesized the 4-hydroxy derivatives of nitrofurazone, furazolidone and nitrofurantoin. Then we dosed rats orally with these antibiotics and isolated the intensely yellow, polar metabolites from their urine. A comparison of the ultraviolet and nuclear magnetic resonance spectra of these metabolites with the corresponding synthetic derivatives confirmed that the metabolites are 4-hydroxynitrofurazone, 4-hydroxyfurazolidone and 4-hydroxynitrofurantoin.