Design,Synthesis And A Pplications Of Several Fluorescent Molecules With Biological Detection And Diagnostic Function

As an important electron withdrawing group?cyano has been broadly applied in the design of fluorescent dyes and drug molecules.It is always one of the hottest research topics of the near-infrared(NIR)organic small molecule fluorescent probes to further improve the sensitivity,stability and aqueous solubility of probes based on novel cyano-based near-infrared fluorescent dyes.This thesis focused on the synthesis of dicyano-based near-infrared fluorescent dyes and on developing a series of near-infrared fluorescent probe via structural modification and introduction of different recognition groups,as well as exploring their application in the theranostic prodrugs.In addition,the dicyanoisophorone-vitamin D derivatives were also studied because of the excellent properties of the dicyanoisophorone-based fluorescent dyes and the important role of cyano in the physiological functions of the drugs.The main research contents about the thesis are listed as follows:1.The dicyanoisophorone was obtained by Knoevenagel reaction from isophorone,then,5 kinds of near-infrared probes were synthesized for different guest detections with acrylate,picolinamide,aryl boronate and maleimide as the recognition groups.The detection limits of the selected probe 2.2 and 2.6 for H2O2 were found to be as low as 0.42?mol and 0.78 ?mol,while the response time from initiation to equilibrium were 30 min and 50min.respectively.More importantly,the synthesis of the probe 2.2comprised only two steps with a yield of 65%.The celluar imaging experiments indicated that the probe 2.2could be used to detect H2O2 within HeLa cell successfully.2.The dicyanomethylene-4H-benzopyran derivatives were synthesized over four steps starting from 2-Hydroxyacetophenone firstly.Subsequently,3 kinds of NIR fluorescent probes were developed on the basis of dicyanomethylene-4H-benzopyran derivatives as the fluorophore and pyridine,pyridyl formate and phenylboronic acid as the receptor,respectively.The selected probe 3.7 featured rapid response to H2O2 in 30 min and the limits of detection was 0.16?mol.Besides,it also exhibited better aqueous solubility,photostability and selectivity.Finally,the effect of chromatic aberration while detecting H2O2 in HeLa cell was also obviously significant.3.A selective and ratiometric turn-on fluorescent probe for cysteine(Cys)4.2 was designed and synthesized by using a naphthalene-modified dicyanoisophorone-based derivative as the fluorophore and acrylate moiety as the recognition group.The probe 4.2 displayed good photostability,excellent selectivity and can avoid the interference of glutathione(GSH)and homocysteine(Hcy).It also exhibited rapid performance to Cys within 180 s.Most importantly,the fluorescence intensity ration at 590 and 525 nm(I590/I525)was depended linearly on the Cys concentration in the range from 0 to 40?mol and the detection limit was calculated to be 0.48 ?mol.This probe was also applied in celluar image of intracellular Cys with significant effects but low cytotoxicity in living HeLa cells.4.DSVD,a near-infrared theranostic prodrug,was obtained by dicyanoisophorone derivative as fluorophores and vitamin D2 as an active drug,which was connected by disulfide liner.Subsequently,4-amino-N-ethyl-1,8-naphthalic anhydride was used as another fluorescent backbone to obtain the reference prodrug NSVD.In reaction to GSH,the disulfide liner of the both prodrugs could be cleaved,releasing the fluorophores and active vitamin D2 concomitantly.The detection limits of GSH for the prodrug DSVD and the reference prodrug NSVD were 0.87?mol and 1.98?mol and the response times were 50 and 30 min,respectively.The probes both demonstrated notable fluorescence enhancements in the pH range of 6-10 and also showed excellent selectivity for GSH.While the excitation wavelength is 555nm,the fluorescence emission wavelength of the prodrug DSVD is 660 nm,which made near-infrared fluorescence detection available.Besides,the prodrug DSVD has similar anticancer activity to vitamin D2 and the ability to monitor the release of the drug visually.5.The dicyanoisophorone-vitamin D derivative with fluorescence enhancement was prepared via aldol condensation and Steglich esterification reaction using dicyanoisophorone as the raw material.With the aid of the microwave-assisted heating technology,the yield of the target product was increased(from 64.1%to 80.2%)and the reaction time was shortened(from 2 h to 15 min)in the esterification reaction.Subsequently,a series of coumarin-vitamin D derivatives were obtained by the esterification of VD2 or CD alcohols with 12 kinds of prepared coumarin-3-carboxylic acids substituted by different groups.It was shown that the fluorescence performance of dicyanoisophorone-vitamin D derivative(?em=500 nm)was better than the coumarin-vitamin D derivatives(Xem=460nm)and was more suitable for the application in fluorescence analysis.