title: Evidence for diazotization of 14C-sulfamethazine [4-amino-N-(4,6-dimethyl-2-pyrimidinyl)benzene[U-14C]sulfonamide] in swine. The effect of nitrite.
abstract: Dietary nitrite greatly enhanced the conversion of orally administered 14C-sulfamethazine (4-amino-N-(4,6-dimethyl-2-pyrimidinyl)benzene[U-14C]sulfonamide; 14C-sulmet) to 14C-desaminosulfamethazine [N-(4,6-dimethyl-2-pyrimidinyl)benzene[U-14C]sulfonamide; 14C-DA-sulmet] in swine. The disposition of 14C orally administered to swine as 14C-sulfamethazinediazonium tetrafluoroborate (4-[N-(4,6-dimethyl-2-pyrimidinyl)sulfonamido] [U-14C]diazonium tetrafluoroborate) was very similar to the disposition of 14C given to swine as 14C-sulmet in combination with nitrite. These results and other information discussed in the text provide evidence that 14C-sulmet, in the presence of nitrite under the acid conditions in the gastrointestinal tract, was diazotized and that this diazonium intermediate was converted to 14C-DA-sulmet and other unidentified 14C-labeled products.
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003979:Diazonium Compounds / Q000378:metabolism*; D005260:Female; D008297:Male; D013058:Mass Spectrometry; D009566:Nitrates / Q000494:pharmacology; D009573:Nitrites / Q000494:pharmacology*; D013055:Spectrophotometry, Infrared; D013418:Sulfamethazine / Q000378:metabolism* / Q000493:pharmacokinetics; D013552:Swine; D014018:Tissue Distribution
chemical_list: D003979:Diazonium Compounds; D009566:Nitrates; D009573:Nitrites; D013418:Sulfamethazine