单嘧磺隆晶体-活性构象转换的分子动力学模拟

应用分子动力学模拟方法对单嘧磺隆在水、正辛醇和正辛烷3种不同溶剂中的构象行为、单嘧磺隆与3种溶剂之间的相互作用能及氢键相互作用进行了计算研究. 计算结果表明, 在3种不同的溶剂中, 单嘧磺隆的优势构象不同; 其构象转换过程, 特别是转换成活性构象的过程主要发生在水溶液中; 与溶剂分子间的相互作用是分子构象行为的决定因素; 单嘧磺隆的脲桥部分可以和含氢键接受体的溶剂形成氢键, 分子间与分子内氢键的竞争可能是从晶体构象转换成活性构象的主要驱动力.

Molecular Dynamics Simulation of Conformational Conversion Between Crystal Conformation and Active Conformation of Herbicidal Monosulfuron

Molecular conformation plays an essential role in the activity of monosulfuron. To understand the conformational conversion, especially how to convert to an active conformation, herein, the conformational behavior in water, n-octanol and n-octane solutions, the interaction energies with these three different solvents and hydrogen bond interaction with solvents of monosulfuron were investigated by a series of molecular dynamics simulations. The simulation results indicate that dominative conformations were different in different solvents, and the conformational conversion, especially converting to an active conformation, was mainly occurs in the aqueous solution in the plant. The calculation results also implies that the interaction between the monosulfuron and solvents was main factor which determined the conformational behavior of monosulfuron. The NH group in the sulfonylurea bridge may interact with the solution which has hydrogen bond acceptor atoms through hydrogen bond, and the competition between forming internal N-H-N hydrogen bond and forming hydrogen bond with solution was probably the driven force from crystal conformation to active conformation conversion.