均三氮苯类除草剂结构与活性的理论研究

Theory study on the structure-activity relationship for 1,3,5-triazine herbicide

利用Gaussian03程序包中的B3LYP方法,选择6-31G基组对均三氮苯类除草剂及类似衍生物2-(4-溴苄氨基)-4-甲基-6-三氟甲基-1,3,5-三氮苯进行了量子化学计算,从理论上讨论了它们的空间结构、电子结构特征与活性的关系.计算结果表明:三氮苯环与N(7)和N(8)原子形成了共轭结构,分子活性大小与LUMO轨道的得电子能力以及在LUMO轨道中占主要成分的原子有重要关系.N(7)和N(8)连接单个具有推电子能力的基团,有利于生物活性的提高.对于2-(4-溴苄氨基)-4-甲基-6-三氟甲基-1,3,5-三氮苯中,N(8)和C(9)是重要的活性部位,和传统的均三氮苯类除草剂分子相比,与D1蛋白上不同的氨基酸残基发生了键合作用.

Using B3LYP method with 6-31G basis sets, the quantum properties of triazine herbicide and 2-（4-bromobenzylamino）-4-methyl-6 trifluoromethyl-1, 3, 5-triazine were analyzed. The electronic structure, steric structure, and activity relationship were discussed theoretically. The computational results showed that the N （7）, N（8） and 1,3,5-triazine ring were conjugated. The activity of this kind of herbicide depends on the energy of LUMO and the distributior pattern of LUMO. The activity will be increased by electron donating substituents on N（7） and N（8）. In the derivatives of 2-（4-bromobenzyl-amino）-4-methyl-6-trifluoromethyl-1,3,5 triazine, the atoms of N（8）, C（9） were the important active parts,it was considered to bind to the different amino acid residue（s） at the D1 protein as traditional striazine herbicides.