基于吲哚的溶酶体荧光探针的合成及应用

Synthesis and Application of Indole-Based Lysosome Fluorescent Probe

目的设计合成一种用于溶酶体成像的荧光探针。方法使用芦竹碱和4-吡啶甲醛作为反应底物,正三丁基膦作为催化剂合成得到化合物(E)-3-(2-吡啶-4-乙烯基)-1 H-吲哚(PVI)。通过核磁对化合物的结构进行表征;荧光光谱法和紫外-可见光吸收光谱法探究该探针与溶液pH之间的关系;理论计算其pH响应的机理;倒置荧光显微镜观察其细胞成像情况;激光共聚焦显微镜记录其溶酶体共定位成像。结果所制备的溶酶体荧光探针PVI在pH 4.00~7.00时,荧光强度随着pH的减小而逐渐增强。PVI具有较低的细胞毒性,可以用于PC-3前列腺癌细胞和其溶酶体成像。结论合成得到一种pH响应的荧光探针PVI,具有细胞毒性低、生物相容性好、荧光强度高的优点,能用于溶酶体定位和成像,是一种具有商业应用价值的溶酶体荧光探针。

Objective To design and synthesize a fluorescent probe for lysosomal imaging.Methods The compound(E)-3-(2-pyridine-4-vinyl)-1 H-indole(PVI)was synthesized by using racholine and 4-pyridine formaldehyde as substrates and n-tributylphosphine as catalyst.The structure of the compounds was characterized by nuclear magnetic resonance(NMR).The relationship between the probe and the pH of the solution was explored by fluorescence spectroscopy and UV-vis absorption spectroscopy.The mechanism of pH response was estimated by theoretical calculation.The cell imaging was observed by inverted fluorescence microscope.The lysosomal co-localization imaging was recorded by confocal laser scanning microscopy.Results The fluorescence intensity of PVI was gradually increased with the decrease of pH when the pH range from 4.00 to 7.00.PVI had low cytotoxicity and could be used for imaging PC-3 prostate cancer cells and their lysosomes.Conclusion A pH-responsive fluorescent probe PVI has been synthesized,and shows the advantages of low cytotoxicity,good biocompatibility,and high fluorescence intensity.As a lysosome fluorescent probe with,it can be used for lysosome localization and imaging,and has commercial application value.