Casida J E, Ueda K, Gaughan L C, Jao L T, Soderlund D M
Arch Environ Contam Toxicol. 1975;3(4):491-500. doi: 10.1007/BF02220819.
The metabolism of 20 pyrethroids has been examined to evaluate the contribution of detoxification in their selective action between insects and mammals. The studies utilized living houseflies, mice, or rats, or esterase and oxidase systems derived from these organisms. Pyrethroid-hydrolyzing esterases cleave the primary alcohol trans-substituted-cyclopropanecarboxylates much faster than the corresponding cis-isomers but are ineffective in hydrolyzing secondary alcohol esters. Microsomal enzymes oxidize the (+)-trans-chrysanthemate moiety at the trans-methyl group of the isobutenyl substituent and at one of the gem-dimethyl groups whereas the (+)-cis-isomer is attacked at either of the isobutenyl methyl groups. Products isomerized at C3 of the cyclopropane are also detected but only after ester cleavage and oxidation of an isobutenyl methyl group. Each alcohol moiety has its own unique sites for oxidation involving pentadienyl, allyl, benzylic methylene, and aromatic substituents. An enhancement of insecticidal activity is expected on replacement of the biodegradable groupings with substituents relatively resistant to metabolism but this may also increase the mammalian toxicity.
已对20种拟除虫菊酯的代谢进行了研究，以评估解毒作用在其对昆虫和哺乳动物选择性作用中的贡献。这些研究使用了活体家蝇、小鼠或大鼠，或源自这些生物体的酯酶和氧化酶系统。拟除虫菊酯水解酯酶切割伯醇反式取代环丙烷羧酸酯的速度比相应的顺式异构体快得多，但对仲醇酯的水解无效。微粒体酶在异丁烯基取代基的反式甲基和偕二甲基之一处氧化（+）-反式菊酸部分，而（+）-顺式异构体则在异丁烯基甲基之一处受到攻击。在环丙烷的C3处异构化的产物也能被检测到，但这仅在酯裂解和异丁烯基甲基氧化之后。每个醇部分都有其独特的氧化位点，涉及戊二烯基、烯丙基、苄基亚甲基和芳族取代基。用对代谢相对抗性的取代基取代可生物降解基团有望增强杀虫活性，但这也可能增加对哺乳动物的毒性。
