Microsomal metabolism of parathion

Enzymes Involved in the Metabolism of Plant Allelochemicals

“…The mechanism of this reaction has been studied with liver microsomes and is analogous to an epoxide formation followed by spontaneous rearrangement whereby elemental sulfur may become covalently bound to the active site of the enzyme (Nakatsugawa and Dahm, 1967;Nakatsugawa and Morelli, 1976).…”

Blood Cholinesterases as Human Biomarkers of Organophosphorus Pesticide Exposure

“…Parathion. Figure 4 gives the metabolic pathway for parathion in the rat (Menzie 1966;Neal 1967a,b;Nakatsugawa and Dahm 1967;Sultatos andGagliardi 1990, Zhang andSultatos 1991 ). The P=S group of parathion, like that of isofenphos, is converted to P=O (desulfurization) by P-450 isozymes to give paraoxon, or parathion is oxidatively cleaved to yield its respective alkyl phosphate ( 0,0-diethyl phosphorothioate) (reactions 1 and 2).…”

Metabolism of Parathion by Two Species of Rhizobium1

“…The more toxic oxidative activation analog of parathion, paraoxon, which is nearly always formed when parathion is administered to a mammal or an insect, (Hazleton 1955, Casida 1956, Krueger et al 1960, Nakatsugawa and Dahm 1965, Nakatsugawa and Dahm 1967a, Nakatsugawa and Dahm 1967b, Neal 1967, Nakatsugawa et al 1968, Nakatsugawa et al 1969 was not detected in this investigation. Ahmed and Casida (1958) found "little if any oxidation" of parathion, Dow ET-57, dimefox, and schradan by pure cultures of the green alga Chlorella pyrenoidosa (Emerson's strain).…”