PHENTHOATE METABOLITES IN HUMAN POISONING

Five metabolites were detected in the plasma and urine of a patient fo llowing ingestion of the organophosphate insecticide, phenthoate. Inta ct phenthoate was detected only in gastric lavage fluid. After methyla tion of acidic extracts of plasma and urine, phenthoate acid, demethyl phenthoate, demethyl phenthoate oxon acid, demethyl phenthoate S-isom er, and demethyl phenthoate acid S-isomer were identified with synthes ized phenthoate analogues by gas chromatography and gas chromatograph- mass spectrometry. The main metabolites were phenthoate acid and demet hyl phenthoate oxon acid. Although demethyl phenthoate oxon acid was a significant metabolite, no phenthoate oxon, phenthoate oxon acid or d emethyl phenthoate oxon were detected. If the oxon was formed in the p atient, it may have been rapidly degraded by carboxylesterase or gluta thione transferase to demethyl phenthoate oxon acid.