菊糖同分异构体活性的密度泛函研究

采用密度泛函(DFT)中B3LYP方法,在6-311+G(d,p)基组水平上对葡萄糖、吡喃型果糖、呋喃型果糖、D-万寿菊糖进行了几何构型优化、频率分析、红外光谱、自然电荷布居、NBO分析、分子能量及前线轨道能级计算,推导出分子的稳定性顺序为:呋喃型果糖吡喃型果糖葡萄糖菊糖.引入概念DFT活性指数分析表明菊糖分子的化学势μ数值大、化学硬度η小、亲电指数ω大,表明了它具有特殊的活性.Fukui指数扫描表明菊糖分子中C2原子具有较大的给电子能力,是整个分子的活性中心.抗氧化能力的EBDE数值计算表明2-H最容易断裂,其数值是为94.65 kcal·mol-1,远小于它的绝热电离势,这可为解释菊糖分子的抗氧化活性做合理的理论指导.

Density Functional Theory Research of Synanthrin Isomers' Activity

By using density functional theory （DFT） method in B3LYP on the 6-311 ＋ G （d,p） basis set level,we have researched the geometric structure optimization,frequency analysis,infrared spectroscopy,natural charge population,the NBO analysis,the molecular energy and frontier orbital the calculation of energy about glucose,pyranose fructose,furfuran fructose,D-marigold synanthrin.The results has shown the activity order was：furfuran fructose ＞pyranose fructose ＞ glucose ＞ synanthrin.We have found that synanthrin＇s chemical potential was more larger,the chemical hardness was more smaller,and the electrophilicity index was more larger by concept DFT activity analysis,which could indicated that it has a special activity.The Fukui function scan has shown the C2 atom in synanthrin molecule has larger electron giving ability,and it was the active center of the whole molecule.The EBDE numerical calculation has shown capacity of 2-H was most easily broken,and the value was 94.65 kcal· mol-1,which was far less than the adiabatic ionization potential,all of that may be a reasonable theoretical guidance for the antioxidant activity of interpretation of synanthrin molecule.