Design,Synthesis And Properties Of Novel Thiazole Orange Derivatives As Fluorescent Probes For G-quadruplex DNA

In the genome of human key regulatory regions,such as telomeres,protooncogene promoter regions,non-transcribed mRNA regions and ribosomal DNA regions,there are many G-rich sequences,and under certain conditions they can form G-quadruplex structure.The formation and disassembly of these structures may affect the normal physiological activities of the cells,but the function and structure of G-quadruplex DNA in vivo is not fully understood.Fluorescent small molecule ligands have good bioaffinity and optical properties and are capable of localizing to the location of the G-quadruplex.By developing a fluorescent small molecule G-quadruplex probe,we can directly observe and detect the distribution of G-quadruplex in vivo,and explore its structure and function.Therefore,study the structural changes of G-quadruplex on genetic material such as DNA.The regulation of life has great significance.Thiazole Orange(TO)is a kind of nucleic acid fluorescent dye with excellent performance.This kind of dye has the characteristics of high sensitivity and high affinity.However,this kind of dye can not selectively recognize G-quadruplex DNA.Fatty amino and styryl groups are introduced to enhance their solubility,sensitivity and selectivity.We designed Compound 1-10 by introducing a fatty amino group;we designed and synthesized compounds A1-5,B1-5 and C1-5 by simultaneously introducing a fatty amino group and a styrene group.It is applied to the fluorescence imaging of nucleic acids in different environments,as well as the study of binding force,selectivity,sensitivity and photostability.The main contents of this paper include:(1)A series of derivatives were synthesized on the basis of thiazole orange skeleton.The fluorescence properties of thiazole orange derivatives were studied by fluorescence spectrometer.Among them,thiazole orange derivatives 1-10 are a kind of universal nucleic acid dyes with high light stability and sensitivity;thiazole orange derivatives A3,C3 and C5 have special G-quadruplex DNA selectivity,and are a kind of high selectivity,high light stability and high sensitivity.G-quadruplex DNA probe with high sensitivity.(2)The fluorescence imaging functions of thiazole orange derivatives 1-10,A3,C3 and C5 were studied by polyacrylamideelectrophoresis and cell imaging.(3)The mode of action of thiazole orange derivatives A3,C3 and C5 and G-quadruplex DNA was studied by UV spectrometer and small molecule docking simulation.The results show that the thiazole orange fatty amino derivative 1-10 designed and synthesized in this thesis is a general-purpose nucleic acid fluorescent dye,which has higher sensitivity,solubility and photostability than the parent thiazole orange.Design of synthetic thiazole orange fatty amino and styryl co-substituted derivatives,A3 and C3 with dimethylaminostyryl and fatty amine side chains and diphenylaminostyryl and pyrrolidine fatty amine side chain C5 exhibits G-quadruplex DNA selectivity through UV,fluorescence,cell imaging,polyacrylamide electrophoresis and small molecule docking simulations.It was found that A3 and C3 can be used as a telomere G-quadruplex fluorescent probe,and C5 can be used as a protooncogene pu27 G-quadruplex fluorescent probe.