4-Acetamidobenzenesulfonamide is a metabolite of the herbicide asulam and the sulfonamide antibiotic sulfanilamide .It is formed from asulam by conversion to sulfanilamide via intestinal microflora, followed by N4-acetylation in the liver. 4-Acetamidobenzenesulfonamide inhibits carbonic anhydrase II (CAII), CAIX, and CAXII (Kis = 246, 135, and 49 nM, respectively, for the human enzymes). It has also been used in the synthesis of compounds with antibacterial activity.