胆红素二甲酯与铜离子配合物的激发态光谱特性研究  

Excited State Dynamics of Bilirubin Dimethyl Ester-Copper Ions Complex

作　　者：闫姝君 刘阳依 和晓晓 郑名 曹潇丹[1] 徐建华[1] 陈缙泉 YAN Shu-jun;LIU Yang-yi;HE Xiao-xiao;ZHENG Ming;CAO Xiao-dan;XU Jian-hua;CHEN Jin-quan(State Key Laboratory of Precision Spectroscopy,East China Normal University,Shanghai 200062,China)

机构地区：[1]华东师范大学精密光谱科学与技术国家重点实验室,上海20006

出　　处：《光谱学与光谱分析》2020年第6期1674-1678,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金委面上基金项目(11674101,21873030)资助。

摘　　要：胆红素二甲酯(bilirubin dimethyl ester,BRE)是一种线性四吡咯,是胆红素(Bilirubin,BR)的类似物[1-3]。用UV,IR,MS等光谱表征BR与BRE,结果并无明显差别。BR/BRE可与多种金属离子形成配合物。BR与金属离子的配位点主要是吡咯氮和丙酸侧链,用甲基取代BR丙酸侧链羧基上的氢得到BRE,使金属离子只与吡咯氮配位。因此本文采用酯化的胆红素BRE研究其与金属离子的作用,优点是可以减少与金属的配位点,降低产物复杂程度,有助于光谱分析。Bilirubin dimethyl ester(BRE)is a linear tetrapyrrole which is an analogue of bilirubin(BR)[1-3]/There is no significant difference betweenthe UV,IR and MS spectra of BR and BRE.BR/BRE can form complexes with a variety of metal ions.The coordination sites of BR and metal ions are mainly the pyrrole nitrogen,and propionic acid side chains,and the hydroxyl groups of the BR propionic acid side chains couldbe substituted with methyl groups to obtain BRE so that the metal ions only coordinate with the nitrogen on the pyrrole ring.Therefore,we have used esterified bilirubin BRE to study its interaction with metal ions,which has the advantages of reducing the coordination point with the metal,as well as the complexity of the product,and contributing to the spectral analysis.Metal ions have an effect on the fluorescence characteristics of BR/BRE.Unlike the fluorescence enhancement of Zn^2+,Cu^2+has an obviousfluorescence quenching on BRE.Studies have shown that hyperbilirubinemia and gallstones are related to BR and copper ions[4-7].Therefore,studying the interaction of bilirubin and its analogues with Cu^2+is of great significance for the prevention and treatment of these diseases.When linear tetrapyrrole molecules coordinate with metal ions,they generally transform from the original chain structure to a porphyrin-like ring structure to suit the coordination with the central ion,a copper ion and the four central pyrrole nitrogens on a BR/BRE molecule coordinate to form a metal-centre square planar structure(Fig.1).BRE itself has a relatively low fluorescence quantum yield because the vibration of the pyrrole ring causes some excited molecules to decay to the ground state in a non-radiative manner[8].Coordination of Cu^2+with BRE may cause their energy levels to couple to generate a new non-radiative de-excitation pathway leading to a decrease in fluorescence,but further research is needed on the quenching mechanism of Cu^2+on BRE fluorescence.The de-excitation processes of the excited state molecules generally occur on

关 键 词：胆红素二甲酯 铜离子 瞬态吸收光谱 配体金属电荷转移 

分 类 号：O657.3[理学—分析化学]