ENDOTHAL AND CANTHARIDIN ANALOGS - RELATION OF STRUCTURE TO HERBICIDAL ACTIVITY AND MAMMALIAN TOXICITY
ENDOTHAL AND CANTHARIDIN ANALOGS - RELATION OF STRUCTURE TO HERBICIDAL ACTIVITY AND MAMMALIAN TOXICITY
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DOI：
10.1021/jf00077a045
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发表时间：
1987-09-01
影响因子：
6.1
通讯作者：
CASIDA, JE
中科院分区：
文献类型：
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作者：
MATSUZAWA, M;GRAZIANO, MJ;CASIDA, JE
通过Diels-Alder反应合成了除草剂草多醛（exo，exo-7-oxabicyclo[2.2.1]heptane-2，3-dicarboxylic acid）的类似物（exo，exo-7-oxabicyclo[2.2.1]heptane-2，3-dicarboxylic acid）。在稗草和野芥菜中测定了它们作为根伸长抑制剂的作用，并测定了腹腔内给药对小鼠的急性毒性。对43个类似物的研究表明，桥氧的空间排列和两个羧酸基团的exo，exo位置对除草活性的重要性。exo，exo位置促进分子内氢键和形成稳定的金属离子络合物。由于桥氧周围的空间位阻，添加环取代基会降低草醛的除草活性。哺乳动物毒性一般遵循相同的模式，除了2，3-二甲基取代形成藜芦苷增加活性。除草活性和对小鼠毒性的结构-活性关系有些相似，表明在植物和哺乳动物中可能存在相关的氧杂双环庚烷靶位点。
Analogues of the herbicide endothal (exo,exo-7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid) with various ring substituents and including several geometrical isomers were synthesized via Diels-Alder reactions. They were assayed as inhibitors of root elongation in barnyard grass and wild mustard and for acute toxicity to mice on intraperitoneal administration. Studies with 43 analogues demonstrate the importance for herbicidal activity of the spatial arrangement of the bridged oxygen and the exo,exo positions of the two carboxylic acid groups. The exo,exo positions facilitate intramolecular hydrogen bonding and formation of stable metal ion complexes. The herbicidal activity of endothal is reduced on adding ring substituents due to steric hindrance around the bridged oxygen. Mammalian toxicity generally follows the same pattern except that 2,3-dimethyl substitution to form cantharidin increases activity. Somewhat similar structure-activity relationships for herbicidal activity and toxicity to mice suggest the possibility of a related oxabicycloheptane target site in plants and mammals.