Metabolism of 2‐chloro‐N‐isopropylacetanilide (propachlor) in the sheep and milk goat

Abstract

Sheep metabolized a single oral dose of 2‐chloro‐N‐isopro‐pylacetanilide (propachlor) to four urinary metabolites. These were 2‐(S‐cysteinyl)‐N‐isopropylacetanilide and 2‐S‐(N‐acetyl) cysteinyl]‐N‐isopropylacetanilide and the glucuronide conjugates of 4'‐hydroxy‐N‐isopropyl‐2‐methylsulfonylacetanilide and N‐(1‐hydroxyisopropyl)‐2‐methylsulfonylacetanilide. Residues (ppb equivalents of propachlor) from ¹⁴C]‐propachlor in the milk from a goat given daily oral doses (1.3 mg of propachlor three times daily for 15 days) plateaued at about 2 to 4 ppb equivalents of propachlor. In goat tissue, residues ranged from 1 ppb (fat) to 20 ppb (liver). Fecal and tissue metabolites were not identified.