Synthesis And Application Of Novel Fluorescent Probe Molecules Based On BODIPY Framework

In 1968,Treibs and Kreuzer first synthesized the BODIPY dye nucleus and a series of derivatives.Due to its all substituent groups are alkyl groups without any reactivity,the dye have not received much attention from researchers.Since the appearance of water-soluble BODIPY,people were attracted by BODIPY dyes Once again.BODIPY dyes have high fluorescence quantum yield,large molar absorption coefficient,photochemical stability,thermal stability and other characteristics.The BODIPY parent can be chemically modified to regulate the photophysical properties and present new photophysical phenomena.Therefore,BODIPY has been greatly developed and widely used in the fields of fluorescent probes,biological imaging,photosensitizers,solar cells and tunable dye lasers.However,as an organic dye,small Stokes shift and poor water solubility limit the further development of BODIPY.At present,the introduction of water-soluble groups and the improvement of the properties of long Stokes shift will greatly broaden the application field.This paper carried out a series of structural modifications to the BODIPY mother nucleus by introducing a triple pyridine with a large conjugate and a specific recognition site and a water-soluble carboxylic acid,amino acid groups.Some novel fluorescent probe molecules have been applied to small molecule recognition and cell imaging.This paper mainly consists of two parts:1.The synthesis and application of BODIPY containing tripyridyl group as fluorescence probe of HNO in vivo were studied.As a protonated product of highly active nitric oxide(·NO),nitrosyl hydrogen(HNO)has unique redox and biological properties,It can directly target the ryanodine receptor and sarcoplasmic reticulum calcium ATPase in myocardium,increase Ca²⁺circulation and cardiac contraction,induce vasodilation,inhibit platelet aggregation,and restrict the proliferation of vascular smooth muscle cells.However,the current detection of HNO in vivo still has shortcomings such as sensitivity,specificity,real-time detection and visual detection.In this part,we designed and synthesized the reactive BODIPY fluorescent probe molecule that was applied to detect HNO.Based on the photoinduced electron transfer mechanism,fluorescence quenching occurs when BODIPY probe BTPY with tribipyridine group complexates with Cu²⁺.With the addition of reducing HNO,the Cu²⁺ion in Cu(?)-BTPY is reduced to Cu⁺,and then fluorescence recovery is achieved,thus realizing the fluorescence"ON-OFF-ON"process.Cu²⁺has a higher sensitivity and better selectivity for the quenching of BTPY in the whole process.Compared with another ROS and RNS,Cu(?)-BTPY achieved a strong specific recognition for the detection of HNO,and the fluorescence enhancement was up to 250 times.On this basis,we further realized the fluorescence imaging of exogenous HNO by Cu(?)-BTPY in Hela cells.In order to further expand the application of such fluorescent probes in vivo,we used BTPY to perform biological staining on the complex organic tissue zebrafish embryos,and achieved good fluorescence imaging effect.2.The synthesis and application of BODIPY containing phenol ester group as fluorescence probe of ONOO^-in vivo were studied.In a variety of pathological and physiological processes,the diffusion reaction of superoxide(·O₂^-)and nitric oxide(·NO)produces a strong oxidation of peroxynitrite(ONOO^-),which can oxidize and Damage to important biomolecules such as proteins,lipids,nucleic acids,and transition metalloenzyme centers.Studies have shown that many diseases such as neurological diseases,cardiovascular diseases,inflammation and cancer are associated with abnormal levels of ONOO^-.Therefore,it is important to carry out the detection of organisms of ONOO^-.In this part,reactive BODIPY fluorescent probe molecules were designed and synthesized and applied to the detection of ONOO^-.In this work,the nucleophilic property of ONOO^-was used to catalyze the hydrolysis of phenol ester to achieve the fluorescence change of BODIPY probe,so as to realize the detection of ONOO^-in water.In this process,water-soluble acetic acid and N-acetyl-L-phenylalanine were introduced into the BODIPY probe,and an Ac-BODIPY probe and an Ac-Phe-BODIPY probe with a phenol ester structure were designed and synthesized.Both probes specifically recognize ONOO^-and exclude interference from other RNS and ROS.We have demonstrated its recognition mechanism by ESI-MS and ¹H NMR.Fluorescence imaging of HeLa cells was achieved by adding exogenous ONOO^-,indicating that the synthesized fluorescent probes have potential application prospects in vivo.