Fukuto T R
J Environ Sci Health B. 1983;18(1):89-117. doi: 10.1080/03601238309372359.
Impurities such as O,S,S-trimethyl phosphorodithioate (TMPD) and the S-methyl isomer of malathion (isomalathion) strongly potentiated the mammalian toxicity of malathion. In contrast, impurities present in the phosphoramidothioate insecticide acephate had an antagonizing effect on its mammalian toxicity. The potentiation of the toxicity of malathion was attributed to inhibition of mammalian liver and serum carboxylesterase. O,O,S-Trimethyl phosphorothioate (TMP), another impurity present in technical malathion and in other organophosphorus insecticides, proved to be highly toxic. Rats given a single oral dose of TMP at a level as low as 20 mg/kg died over a period of three weeks, with death occurring with non-cholinergic signs of poisoning. TMPD also caused similar delayed death in rats. O,O,O-Trimethyl phosphorothioate (TMP=S), also another impurity in technical malathion and a structural isomer of TMP, was a potent antagonist to the delayed toxicity of TMP. Examination of a number of related trialkyl phosphorothioate and dialkyl alkylphosphonothioate esters revealed several of these compounds to be highly toxic to rats.
杂质如O,S,S-三甲基二硫代磷酸酯（TMPD）和马拉硫磷的S-甲基异构体（异马拉硫磷）能强烈增强马拉硫磷对哺乳动物的毒性。相比之下，硫代磷酰胺类杀虫剂乙酰甲胺磷中存在的杂质对其哺乳动物毒性具有拮抗作用。马拉硫磷毒性的增强归因于对哺乳动物肝脏和血清羧酸酯酶的抑制。O,O,S-三甲基硫代磷酸酯（TMP）是工业用马拉硫磷和其他有机磷杀虫剂中存在的另一种杂质，被证明具有高毒性。给大鼠单次口服低至20mg/kg剂量的TMP，大鼠在三周内死亡，死亡时出现非胆碱能中毒症状。TMPD在大鼠中也会导致类似的延迟死亡。O,O,O-三甲基硫代磷酸酯（TMP=S）也是工业用马拉硫磷中的另一种杂质，是TMP的结构异构体，是TMP延迟毒性的有效拮抗剂。对一些相关的三烷基硫代磷酸酯和二烷基烷基硫代膦酸酯的研究表明，其中几种化合物对大鼠具有高毒性。
