title: Metabolism of mercapturic acid-pathway metabolites of 2-chloro-N-isopropylacetanilide (propachlor) by gastrointestinal bacteria.
abstract: 1. Mercapturic acid pathway metabolites of propachlor, labelled with 14C, were incubated with pig caecal contents, small and large intestinal contents, and pure cultures of gastrointestinal bacteria. 2. The glutathione, cysteine, N-acetylcysteine, and the S-oxide of the N-acetylcysteine conjugates of propachlor (2-chloro-N-isopropylacetanilide) were each metabolized by mixed pig caecal micro-organisms to 2-mercapto-N-isopropylacetanilide. 3. The extent of formation of 2-mercapto-N-isopropylacetanilide by mixed pig caecal micro-organisms from mercapturic acid-pathway metabolites of 14C-propachlor was as follows: glutathione (43.4%), cysteine (32.6%), N-acetylcysteine (5.2%), and the S-oxide of the N-acetylcysteine conjugate of propachlor (6.1%). The S-oxide of the N-acetylcysteine conjugate of propachlor was converted by the mixed pig caecal micro-organisms to N-acetylcysteine and cysteine conjugates of propachlor. 4. Small intestinal contents metabolized the glutathione conjugate of propachlor to the cysteine conjugate; little C-S lyase activity was present in the small intestinal contents. 5. The cysteine conjugate of propachlor was metabolized to 2-mercapto-N-isopropylacetanilide by Fusobacterium necrophorum, Bacteroides vulgatus, Megasphaera elsdenii and Eubacterium aerofaciens.
mesh_terms: D000083:Acetanilides / Q000378:metabolism*; D000111:Acetylcysteine / Q000378:metabolism*; D000818:Animals; D001419:Bacteria / Q000302:isolation & purification / Q000378:metabolism*; D002432:Cecum / Q000382:microbiology; D004064:Digestive System / Q000382:microbiology*; D005285:Fermentation; D007420:Intestine, Large / Q000382:microbiology; D007421:Intestine, Small / Q000382:microbiology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013552:Swine
chemical_list: D000083:Acetanilides; C011088:propachlor; D000111:Acetylcysteine