麻黄碱及其立体异构体ECD谱的理论研究  

Theoretical study of the ECD spectra of ephedrine and its stereo isomers

作　　者：王以武[1,2,3] 张海东[1,2,3] 蒋启华[1,2,3] 蒋君好[1,2,3] 邓萍[1,2,3] 

机构地区：[1]重庆医科大学药学实验中心,重庆400016 [2]重庆市高校催化理论与应用技术重点实验室,重庆400067 [3]重庆高校药物工程研究中心,重庆医科大学药学院,重庆400016

出　　处：《计算机与应用化学》2013年第2期207-210,共4页Computers and Applied Chemistry

基　　金：重庆市教委科学技术研究项目(KJ120307)

摘　　要：采用Gaussian 03、SpecDis v1.58、Multiwfn 2.2.1、Molekel 5.4等软件对麻黄碱及其立体异构体的电子结构及电子圆二色谱（ECD谱）性质进行研究。计算结果表明：（1）电子密度拓扑分析证实麻黄碱及其立体异构体分子的H（7）与N（4）之间存在键鞍点,从该键鞍点出发存在连接H（7）、N（4）的键径,表明形成了分子内氢键。（2）研究获得了理论ECD谱。A1的ECD谱在（184、199、229）nm附近存在正性CD谱带;在188 nm、215 nm附近存在负性CD谱带。B1的ECD谱在184nm附近存在正性CD谱带,在187m附近存在负性CD谱带。C1的ECD谱在185nm、222nm附近存在正性CD谱带,在（192、199、234）nm附近存在负性CD谱带。D1的ECD谱中在186 nm、228 nm附近存在正性CD谱带,在195nm附近存在负性CD谱带。以上吸收特征可为麻黄碱及其立体异构体绝对构型鉴定提供参考信息。（3）分子轨道成份分析发现,A1、C1分子HOLO轨道主要分布在N（4）原子上,而LUMO轨道主要分布在苯环上。A1、C1理论ECD谱中,峰5的吸收带主要来源于HOMO→LUMO的电子跃迁,即主要由N（4）到苯环的n→π~＊荷移跃迁引起。The structures and electronic circular diehroism （ECD） spectra of ephedrine and its stereo isomers were studied using Gaussian 03, SpecDis vl.58, Multiwfn 2.2.1 and Molekel 5.4 programs. According to the theoretical study, we can draw three meaningful conclusions. （1）The electronic density topological analysis shows that there are bond critical points between the H （7） atom and the N （4） atom in ephedrine and its stereo isomers, namely to indicate the formation of intramolecular hydrogen bond in these molecules. （2）The ECD spectra of the ephedrine and its stereo isomers were calculated by time-dependent density functional theory （TD-DFT） to provide useful information for the absolute configuration identification, The results demonstrate that the positive cotton effects at （184, 199, 229） nm and negative cotton effects at （188, 215） nm can be observed in the ECD spectra oral; the positive cotton effects at 184 nm and negative cotton effects at 187 nm exist in the ECD spectra of Bl; the ECD spectra of C1 has positive cotton effects at （185,222） nm and negative cotton effects at （192, 199, 234） nm; and the positive cotton effects at （186, 228） nm and negative cotton effects at 195 nm can be found in the ECD spectra olD1. （3）The orbital composition analysis shows that the orbital electron of HOMO is mainly distributed upon the N（4） atom, and the orbital electron of LUMO is mainly distributed upon the benzene ring. This means that the cotton effects of peak 5 in tile ECD spectra of A1 and Clis mainly caused by the n---π^＊ charge transfer transition, namely from the N （4） atom to the benzene ring.

关 键 词：麻黄碱 立体异构体 圆二色谱 理论研究 

分 类 号：O641[理学—物理化学] R914.5[理学—化学]