新磺酰脲类除草活性构效关系的研究

磺酰脲类除草剂具有对环境友好和超高效的特点。本文采用X-衍射谱对其绝对构型进行分析，首次发现分子内氢键的存在。采用各种理论和软件计算，活性结构应符合三点要求：(a)分子内氢键使杂环和脲之间形成一个共轭体系；(b)羰基氧、磺酰氧和杂环氮形成分子中三个负电中心；(c)在磺酰胺与苯邻位取代基之间形成一个空穴。根据以上结论，构建了一个卡口模型，较合理地解释了磺酰脲类草活性的构效关系。建立了一个虚拟靶酶ALS的模拟作用模型，供进一步分子设计ALS抑制剂，包括一些非磺酰脲类先导化合物时参考。

Research on the structure/activity relationship of herbicidal sulfonylureas

Some sulfonylureas are an important class of environmental benign, ultra-low dosage herbicides. X-ray diffraction spectra of bio-active sulfonylureas were carefully examined and an intra-molecular hydrogen bond was first reported here. By theoretical calculation, three essential structural requirements for the bio-activity were concluded as follows: (a) all intramolecular hydrogen bonds cause a coplanar conjugated system between the heterocycle and urea moiety; (b) carbomyl oxygen, sulfonyl oxygen and heterocyclic nitrogen form three negative centers; (c) between sulfonylamido and phenyl ortho substituent, there is a cavity. A Caliper model thus deduced reasonably explains the structure/activity relationship of bioactive sulfonylureas. A 3-D contour map of a pseudo-ALS model was set up with which could lead to further design of novel ALS inhibitors, including some possible non-sulfonylureas leads.