代谢
敌百虫(1微克)在37°C下与下列小鼠微粒体制剂孵化30分钟;a) 四乙基焦磷酸(TEPP)处理的微粒体(无酯酶和氧化酶活性);b) 正常微粒体(酯酶活性);c) TEPP处理的微粒体加上NADPH(氧化酶活性);d) 正常微粒体加上NADPH(酯酶加氧化酶活性)。敌百虫在氧化酶系统中的代谢速度比在酯酶系统中快。环羟基化的主要位置是4'位,次要位置是5位。转甲基基团是酯羟基化的重要位置,而顺甲基氧化在裂解酸部分的代谢物中是明显的。羟基化的首选位置如下;转二甲基基团,酚组中的4'位,顺二甲基基团等于苯氧基组中的5位。敌百虫裂解成氰醇可能是由于酯酶和氧化酶酶活性,因为在氧化酶系统中裂解产物的量更大。然而,在比上述研究中敌百虫浓度高得多(大约35倍)的情况下,它没有显著水解。敌百虫在小鼠的血液、大脑、肾脏和胃中的酯酶下水解,产生PBald和PBacid。
Deltamethrin (1 ug) was incubated at 37 °C for 30 min with each of the following mouse microsome preparations; a) tetraethyl pyrophosphate (TEPP)-treated microsomes (no esterase and oxidase activity); b) normal microsomes (esterase acivity); c) TEPP-treated microsomes plus NADPH (oxidase activity); and d)normal microsomes plus NADPH (esterase plus oxidase activity). Deltamethrin was more rapidly metabolized under the oxidase system than under the esterase system. The major site of ring hydroxylation was 4'-position and the secondary site was the 5-position. The trans methyl group was an important site of hydroxylation of the esters and cis methyl oxidation was evident in the metabolites of the cleaved acid moiety. The preferred sites of hydroxylation were as follows; trans of dimethyl group, 4'-position in the phenol group, and cis of the dimethyl group was equal to the 5-position in the phenoxy group. Cleavage of deltamethrin to cyanohydrin may result from both esterase and oxidase enzyme activities, since larger amounts of the cleaved products were evident in the oxidase system. ... However, at a much higher (approximately 35-fold) concentration of deltamethrin than that in the above study, it was not detectably hydrolysed. ... Deltamethrin was hydrolysed by esterases in the blood, brain, kidney, and stomach of mice yielding PBald and PBacid.
来源:Hazardous Substances Data Bank (HSDB)