The metabolism of sulphonamides: 5. A study of the oxidation and acetylation of sulphonamide drugs and related compounds in the rabbit.

It has now been established that both the simple and heterocyclic sulphonamides may undergo both acetylation and oxidation in the body (cf. Williams, 1945, 1946, 1947; Dobson & Williams, 1946; Stubbs & Williams, 1947; Bray, Neale & Thorpe, 1946; Gilligan, 1945; Scudi & Silber, 1944; Weber, Lalich& Major, 1943). In the simpler sulphonamides, such as the o-, mand p-aminobenzenesulphonamides, oxidation occurs in the benzene ring, whereas in the N'-substituted sulphonamides, sulphapyridine and sulpliaquinoxaline (Bray et al. 1946; Weber et al. 1943; Scudi & Silber, 1944), oxidation occurs in the heterocyclic ring and acetylation in the benzene ring. The object of the present work was to find out whether in vivo -oxidation and acetylation were related. These two processes could occur in four ways: (1) acetylation followed by oxidation of the acetylatedmolecule, (2) oxidation followed byacetylation of the oxidized molecule, (3) simultaneous oxidation and acetylation of the same molecule, and (4) oxidation and acetylation as separate reactions involving different molecules of the compound: