Additional Route in the Metabolism of Sulphanilamide

Abstract

1. Rabbits were found to excrete a substantial portion of a dose of [³⁵S]sul-phanilamide as N-(4-sulphamoylphenyl)glycolamide (20%) and N-(4-sulpha-moylphenyl)oxamic acid (14%), newly discovered metabolites of sulphanilamide. The metabolites were isolated and identified by u.v., i.r., and n.m.r. spectroscopy.

2. Urine of a human dosed with [³⁵S]sulphanilamide contained only a small portion of the dose as glycolamide (2%), and the oxamic acid derivative was not detected.

3. N-(4-Acetylaminobenzenesulphonyl)acetamide and 4-amino-3-hydroxy-benzenesulphonamide, metabolites of sulphanilamide found in the urine of other species, were shown to be produced also by the human.

4. N-Hydroxy-N-(4-sulphamoylphenyl)acetamide was not detected in the urines of rabbits or human dosed with [³⁵S]sulphanilamide. From human urine a very small amount of a metabolite was isolated which was likely to be a conjugate of N⁴-hydroxysulphanilamide.