丁香对低密度脂蛋白氧化过程中荧光特性变化的影响

低密度脂蛋白(LDL)氧化修饰是导致动脉粥样硬化(AS)的关键因素，LDL在氧化修饰过程中荧光特性会发生一系列改变。为评价丁香对LDL氧化过程中荧光的抑制效果，采用传统荧光及三维荧光等高线光谱研究丁香对LDL氧化修饰过程中荧光特性的影响。结果显示： LDL氧化孵育荧光特性的最佳测定时间为48 h；丁香粗提物对LDL氧化修饰过程中色氨酸(Trp)荧光猝灭、荧光发色团红移、氧化产生的活性醛修饰apoB 100所含赖氨酸(Lys)残基变化、荧光物质和脂褐素产生及三维荧光的变化均具有较好的抑制作用，且抑制作用与粗提物浓度成正相关。在此基础上进一步发现，丁香各极性成分(正己烷相(丁香精油)、乙酸乙酯相、正丁醇相及水相)对LDL氧化修饰过程荧光特征的变化影响不一。其中，正己烷相对Trp荧光猝灭、荧光发色团红移及三维荧光变化的抑制作用最强，而乙酸乙酯相抑制活性醛修饰Lys残基、荧光物质和脂褐素的产生效果最好。结果表明，丁香对LDL氧化修饰过程中荧光特性的变化具有较好的抑制作用，抑制作用的主要物质集中在正己烷相和乙酸乙酯相。该研究为后续丁香组成分析及其功能食品研发提供参考。

The Effect of Clove on the Variation of Fluorescence Characteristic during Low Density Lipoprotein Oxidation

Oxidation of LDL has been regarded as the key factor which leads to AS,the fluorescent characteristic of LDL developed a series of changes during LDL oxidation.The traditional and three-dimensional flourescence contour spectroscopy were used to evaluate the inhibition effects of clove against the changes of fluorescent characteristic of LDL in the process of oxidation in this paper.The results indicated as follows: the optimal measurement time point of LDL incubation for fluorescence was 48 h;fluorescence of Trp quenching,fluorescent chromophore redshift,Lys residues contained in apoB-100 being modified by reactive aldehydes generated during oxidation,the generation of fluorescent materials and lipofuscins and the variation of three-dimensional fluorescence were significantly inhibited,respectively,and the inhibition effects were positively related with concentrations of clove crude extracts.Moreover,in this experiment it was found that the different polarity components of clove(n-hexane fraction(clove essential oil),ethyl acetate fraction,n-butyl alcohol fraction and water fraction)possessed different activities on influencing the changes of fluorescent characteristic of LDL during LDL oxidation.Among these fractions,n-hexane fraction possessed the strongest activities against Trp fluorescence quenching,fluorescent chromophore redshift and the variation of three-dimensional fluorescence.However,the inhibition efficiencies of ethyl acetate fraction were the highest against the generation of fluorescent materials and lipofuscins,Lys residues being modified by reactive aldehydes.The results suggest that clove has the preferable inhibitory action on the variation of fluorescence characteristic during LDL oxidation,and the main components of inhibition focus on the essential oil and ethyl acetate fraction.This research provides a reference on further components analysis,research and development of functional foods of clove.