• 中文核心期刊要目总览
  • 中国科技核心期刊
  • 中国科学引文数据库(CSCD)
  • 中国科技论文与引文数据库(CSTPCD)
  • 中国学术期刊文摘数据库(CSAD)
  • 中国学术期刊(网络版)(CNKI)
  • 中文科技期刊数据库
  • 万方数据知识服务平台
  • 中国超星期刊域出版平台
  • 国家科技学术期刊开放平台
  • 荷兰文摘与引文数据库(SCOPUS)
  • 日本科学技术振兴机构数据库(JST)

天然Alboatisin电子结构和圆二色谱的密度泛函理论研究

Electronic Structure and Circular Dichroism of Natural Alboatisins Isolated from Aerial Parts of Isodon Albopilosus: DFT and TDDFT Study

  • 摘要: 采用蒙特卡罗MMFF94分子力学力场方法搜索一类新发现的生物活性分子Alboatisin A~C的稳定构象,用梯度校正的B3LYP方法,计算其稳定构象的旋光度、振动圆二色谱(VCD)、电子圆二色谱(ECD)等光学活性,并从微观的角度对VCD谱和ECD谱中强或弱的正或负康登效应进行归属.从分子结构、电子结构和分子振动分析了分子手性的微观起源.结果表明,计算与实验的旋光度值相吻合,OH的取代位置与数目可调控旋光度发生在手性骨架上的振动或电子跃迁转移是手性光谱产生的重要原因.Alboatisin的圆二色谱是手性骨架变形振动的光谱响应,是不对称电子跃迁的光谱响应结果.

     

    Abstract: The stable conformations of a series of bioactive molecules, (?)-alboatisins A?C, are identified via Monte Carlo searching with the MMFF94 molecular mechanics force field. Then, the optical rotation (OR) values, vibrational circular dichroism (VCD), and electronic circular dichroism (ECD) spectra were calculated using the gradient-corrected density functional theory method. The vibrational and transition modes of molecular chirality were explored in terms of their microscopic origin. The calculated specific rotations are in agreement with the experimental values. From the OR analysis, it was concluded that optical rotation values areregulated by hydroxyl substitution. Vibrations occurring on the chiral skeleton may cause strong absorption in VCD spectra; VCD spectra are thus the spectral response to deformation vibrations on the chiral carbon skeleton. The lowest-energy negative Cotton effect is caused by σ→π* transition. Frontier molecular orbital analysis showed that strong ECD absorptions are produced when the dominant transition on the chiral skeleton is asymmetric; ECD spectra show the result of transitions lacking asymmetry on the chiral skeleton.

     

/

返回文章
返回