O‐dealkylation and N₄‐acetylation of sulpha‐2‐monomethoxine by the turtlePseudemys scripta elegans

Comparison of the metabolism of four sulphonamides between humans and pigs

“…Sulphonamides are metabolised via N4-acetylation, oxidation, N1-glucuronidation and 0-dealkylation, depending upon the molecular structure and the enzymic composition of the animal species (4,9,14). Recently we were able to measure the N1-glucuronide conjugate of sulphadimethoxine and of sulfa-6-monomethoxine in the urine of man (10,12), but we were unable to find this metabolite in the urine of pigs (6).…”

“…The presence of methoxy groups seems to be the first requirement for N1-glucuronidation, and secondly the 2 and 6 position of the pyrimidine group must be substituted (14,17,18,Vree et al HPLC screening, unpublished results). In general it can be stated that 0-glucuronidation carried out by liver UDPGtransferase is a relatively fast process (7) and 0-glucuronides can be detected in plasma (e.g.…”

Characterization and estimation of sulfaquinoxaline metabolites in animal tissues using liquid chromatography coupled to tandem mass spectrometry

“…16 The same hydroxylation patterns were observed for sulfamonomethoxine in turtles. 17 OH-metabolites, when the hydroxylation occurs in the radical moiety, still possess a free para-aminophenyl group which interferes with para-aminobenzoic acid synthesis in bacteria. 18 Moreover, acetylated metabolites of sulfonamides have no bacterial activity, a lower solubility in physiological pH, which may lead to kidney precipitation, de-acetylation of the parent drug both in vivo and in vitro and higher plasma protein binding than the parent drug.…”