花青素类物质对pH响应的紫外光谱学和理论研究  

A combined experimental and theoretical studies on UV-Vis spectral response of two anthocyanins to different pH

作　　者：童馨苇[1] 韩辉[2] 王丽[2] 董川[2] 

机构地区：[1]山西大学化学化工学院,山西太原030006 [2]山西大学环境科学研究所,山西太原030006

出　　处：《化学研究与应用》2017年第3期401-406,共6页Chemical Research and Application

基　　金：山西省第八批"百人计划"项目(205107001)资助;山西省高校"131"领军人才工程项目(205586801011)资助

摘　　要：本文以氯化矢车菊素和氯化飞燕草色素两种常见花青素为研究对象,检测了它们在不同pH水环境下的紫外-可见吸收光谱,通过研究吸收光谱峰位置的变化,对pH变化过程中物质结构的变化进行了分析;同时通过理论计算对两种物质的结构进行了优化,根据相关数据探讨了该类花青素的电子云分布及其对抗氧化活性的影响。结果表明,随着酸碱度的变化,氯化矢车菊素可能有四种稳定结构的中间态,氯化飞燕草色素可能只有三种,说明母核上羟基取代基的数量和位置对花青素类化合物的活性和稳定性有较大影响,这也会影响其抗氧化活性。理论计算得到的轨道能级数据说明氯化飞燕草色素可能有更好的抗氧化活性;羟基的电荷分布则分析了花青素不同位点的羟基与自由基结合的能力,这也表明氯化飞燕草色素可能有更好的抗氧化活性。This paper examines the UV-Vis spectral change of two anthocyanins（ cyanidin chloride and delphinidin chloride） at different pH in aqueous solution.Spectral deconvolution reveals there are different transitions for each anthocyanin at different pH.This suggests that each anthocyanin exists with different structures at each different pH.Theoretical calculation was also conducted to optimize the most stable structures for two anthocyanins at different pH.The results show that the absorption spectrum of cyanidin chloride varies greatly with the change of pH,and it may have four stable transient structures with the change of pH. The spectrum of delphinidin chloride varies slightly,and it may have three transient structures with the change of pH.The theoretical studies of Mulliken charge distribution of hydroxyl group and the energy of frontier orbitals show that delphinidin chloride may have a better antioxidant activity.

关 键 词：氯化矢车菊素 氯化飞燕草色素 抗氧化活性 紫外-可见吸收 理论计算 

分 类 号：O657.32[理学—分析化学]