次黄嘌呤和别嘌醇的太赫兹光谱弱相互作用研究  

Study on Weak Interaction of Terahertz Spectra for Crystalline Hypoxanthine and Allopurinol

作　　者：张琴 陈涛[1] ZHANG Qin;CHEN Tao(School of Electronic Engineering and Automation,Guilin University of Electronic Technology,Guangxi Key Laboratory of Automatic Detecting Technology and Instruments,Guilin 541004,China)

机构地区：[1]桂林电子科技大学电子工程与自动化学院,广西自动检测技术与仪器重点实验室,桂林541004

出　　处：《分析化学》2020年第8期1058-1066,共9页Chinese Journal of Analytical Chemistry

基　　金：广西自然科学基金项目(Nos.2018GXNSFAA281167,2018GXNSFAA138093);国家自然科学基金项目(No.61841502)资助。

摘　　要：应用太赫兹时域光谱(THz-TDS)技术测量了次黄嘌呤(HPX)和别嘌醇(ALP)两种同分异构体在室温条件下0.1~2.0 THz范围的THz吸收光谱。同时,为进一步分析样品在THz波段的低频振动模式和弱相互作用类型,借助密度泛函理论(DFT)对两者结构进行几何优化,应用势能分布(PED)分析对分子基团的振动模式进行归属,并应用基于分子力场的能量分解分析(EDA-FF)方法对光谱色散特性进行定性分析。PED分析结果表明,HPX团簇的振动方式均为二面角扭转,ALP团簇则为键角弯曲和二面角扭转两种振动方式。EDA-FF数据和原子着色图表明,两者弱相互作用类型都是以静电相互作用为主、色散力为辅,ALP体系内氢键成键数目为HPX体系的两倍,并且色散作用都集中体现在与氢键直接作用的供体与受体原子上。研究结果表明,DFT与PED、EDA-FF分析方法相结合为结构相似的生物分子和分子间非键相互作用的深入研究提供了有价值的参考。The terahertz(THz)spectra of hypoxanthine and allopurinol samples were measured by THz time-domain spectroscopy(THz-TDS)in the range of 0.1-2 THz at room temperature.The geometry structures of these two samples were optimized using density functional theory(DFT).The low frequency vibrations of molecular group for these two samples were assigned using the potential energy distribution(PED)analysis.The spectral dispersion characteristics of samples were qualitatively analyzed by the energy decomposition analysis based on molecular forcefield(EDA-FF)method.PED analysis results showed that the vibration modes of the hypoxanthine cluster were all dihedral angle torsion,while allopurinol cluster were bond angle bending and dihedral angle torsion.EDA-FF data and atomic coloring diagrams indicated that the weak interaction types of the two clusters were dominated by electrostatic,while the amount of hydrogen bonds in allopurinol system were double compared with hypoxanthine,and the dispersion was mainly reflected on the donor and acceptor atoms that directly interacted with hydrogen bonds.The combination of DFT,PED and EDA-FF methods provided a valuable reference for the further study of intermolecular non-bonded interaction and biomolecules with structural similarities.

关 键 词：次黄嘌呤 别嘌醇 太赫兹时域光谱 弱相互作用 基于分子力场的能量分解分析 

分 类 号：O657.3[理学—分析化学] TQ460.1[理学—化学]