木兰花碱的荧光性质及其在中药分析中的应用研究  

Fluorescence Properties of Magnoflorine and Its Application in Analysis of Traditional Chinese Medicine

作　　者：曹津津 孙启瑞[2] 李文红 宋冉冉[2] 曹倩玉 王可 魏永巨[1,2] CAO Jin-Jin;SUN Qi-Rui;LI Wen-Hong;SONG Ran-Ran;CAO Qian-Yu;WANG Ke;WEI Yong-Ju(College of Life Science, Hebei Normal University, Shijiazhuang 050024, China;College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024, China;Department of Environmental and Chemical Engineering, Hebei College of Industry and Technology, Shijiazhuang 050091, China;Shijiazhuang Center for Disease Control and Prevention, Shijiazhuang 050011, China)

机构地区：[1]河北师范大学生命科学学院,石家庄050024 [2]河北师范大学化学与材料科学学院,石家庄050024 [3]河北工业职业技术学院环境与化学工程系,石家庄050091 [4]石家庄市疾病预防控制中心,石家庄050011

出　　处：《分析化学》2019年第6期950-956,共7页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(Nos.20975029;81173496);河北省自然科学基金项目(No.B2014205129)资助~~

摘　　要：研究了木兰花碱(Magnoflorine,MAG)的荧光光谱和吸收光谱特征,考察了pH值等环境因素对荧光和吸光的影响,探讨了光谱性质与分子结构的关系。木兰花碱水溶液的三维荧光图谱中呈现3个荧光峰,激发波长λ_(ex)为230、275和315 nm,发射波长λ_(em)均为420 nm。随溶液pH值升高,激发光谱中的荧光峰红移并出现等荧光点,吸收光谱中的吸收峰红移并形成等色点,表明木兰花碱分子中的1个羟基发生了质子电离,用pH值-吸光法测得电离常数pK_a=4.77。以L-色氨酸为参比,测得木兰花碱水溶液的荧光量子产率Y=0.19。青风藤等多种中药材的三维荧光图谱中呈现木兰花碱的特征荧光峰,λ_(ex)/λ_(em)=315 nm/420 nm处的荧光峰不受共存组分的影响,且荧光强度稳定,据此建立了中药青风藤中木兰花碱的荧光分析新方法。在0.04～1.25μg/mL范围内,体系荧光强度I_F与木兰花碱浓度c呈线性关系,回归方程为:I_F=6146.8c+24.4(R=0.999,n=11),检出限0.52 ng/mL。采用本方法测得青风藤对照药材中MAG的含量为0.63%,加标回收率为101.2%～102.7%。LC-MS/MS法测定结果为0.61%,与荧光法基本一致。本方法简便快速,结果可靠,有良好的实际应用价值。Fluorescence and absorption spectra of magnoflorine(MAG) were studied. The effects of environmental factors such as pH on fluorescence and absorbance were investigated, and the relationship between spectral properties and molecular structure was revealed. Three fluorescent peaks appeared in the three-dimensional(3 D) fluorescence spectra of the aqueous solution of MAG, with excitation wavelengths(λex) of 230, 275 and 315 nm, and the same emission wavelength(λem) of 420 nm. As the pH of the solution increased, the fluorescence peak in the excitation spectrum red-shifted and an equal fluorescence point appeared, and the absorption peak in the absorption spectrum also red-shifted and an isosbestic point formed, indicating that proton ionization occurred in one hydroxyl group in the MAG molecule. The proton ionization constant(pKa=4.77) of MAG was determined by a pH-absorption method. Using L-tryptophan as a reference, the fluorescence quantum yield of the aqueous solution of MAG was determined to be Y=0.19. The characteristic fluorescence peaks of MAG appeared in the 3 D fluorescence spectra of various Chinese herbal medicines. Using methanol-water mixed solvent containing 60% methanol, the extract of Sinomenium acutum(Qingfengteng) was prepared and diluted with water, then 3 D fluorescence spectra were obtained. It was observed that the fluorescence peak at λex/λem=315 nm/420 nm in the spectrum of the Qingfengteng neutral aqueous solution was not affected by the coexisting components. Based on this, a method for the determination of MAG in Qingfengteng was established. In the range of 0.04-1.25 μg/mL, the regression equation for fluorescence intensity(IF) and MAG concentration(c) was IF=6146.8c + 24.4,(R=0.999, n=11), with a detection limit of 0.52 ng/mL. The content of MAG in the Qingfengteng reference material was determined to be 0.63% by the method, and the recoveries were 101.2%-102.7%. The content of MAG(0.61%) in the same sample was also determined by LC-MS/MS method, which was consistent with the fluor

关 键 词：木兰花碱 青风藤 中药 三维荧光 荧光分析 

分 类 号：O657.3[理学—分析化学] R284.1[理学—化学]