Synthesis And Study Of Interaction Between Luminescent Acceptor Based On Stilbene Derivatives And Protein

Proteins played an important role in the orgin and evolution of life and transferring materials. Therefore, investigating the interaction between different kinds of fluorescence receptors and bovine serum albumin (BSA) have become a hot topic in recently years. Molecular recognition based on fluorescence detection has many merits such as high sensitivity, high selectivity and easy operation. We designed and synthesized two kinds of compounds, studied th interactions between them and BSA. This thesis consists of four chapters.In chapter 1, two-photon probes for cation ions (Mg2+, Ca2+, Zn2+, Pb2+, Hg2+, Ag+, Fe3+, Cr3+, Na+), anion ion probes (F-), pH probes, sulfhydryl group probes, cysteine probes were reported domestic and overseas in recent years.In chapter 2,2,5-bis(bromomethyl)terephthalonitrile was synthesized from 2,5-dimethylterephthalonitrile using N-bromosuccinimide (NBS) as brominating agent, then the product react with P(OEt)3 according to Witting-Horner reaction to make Tetraethyl-(2,5-dicyano-a,a'-p-xylenediphosphonate). The new compounds [(2,5-di-[2-(4-hydroxy-phenyl)ethylene]-terephthalonitrile (DHPEPN) and 2,5-di-[2-bis(4-2-pyridylmethyl)amino phenyl)ethylene]-terephthalonitrile (DPMPEPN)] were synthesized from Tetraethyl-(2,5-dicyano-α,α'-p-xylenediphosphonate) and benzaldehyde derivatives. DHPEPN was characterised by 1H NMR spectrum, the result was assigned as follows:'H NMR (600 MHz, DMSO-d6),5 (ppm):9.98(s,2H), 8.46(s,2H),7.63(d, J= 16.2Hz,2H),7.49(d, J= 8.40Hz,4H),7.09(d, J= 16.2Hz,2H), 6.85(d, J= 8.40Hz,4H). DPMPEPN was characterised by 1H NMR spectrum, the result was assigned as follows:1H NMR (600 MHz, DMSO-d6),δ(ppm):8.57(d, J= 3.6Hz,2H),8.36(s,1H),7.76(d, J= 1.8Hz,2H),7.51(d, J= 16.2Hz,1H),7.32(d, J= 7.2Hz,2H),7.32-7.27(m,4H),6.92(1H),6.73(d, J= 9.0Hz,2H),4.90(s,4H).In chapter 3, a new compound, DHPEPN, was synthesized and the interaction between BSA and DHPEPN in Tris-HCl buffer solution (pH 7.40) is investigated using fluorescence and UV-vis absorption spectrometry. Upon addition of BSA, the fluorescence intensity of DHPEPN (460 nm) increased, when at the excitation of 360 nm. The results indicated that the quenching mechanism was mainly belonged to static quench, meanwhile the dynamic of quenching could not be ingored. The values of Kb were estimated as 11.5,0.46 and 0.068,×105 L mol-1 respectively; and n were 1.14,0.87, and 0.71 respectively at different temperatures (298,303, and 308 K). The values of Kb decreased with increasing the temperature. The distance between BSA and DHPEPN was estimated as 3.59 nm based on the Forster resonance energy transfer (FRET) theory. The spectral changes of synchronous fluorescence and three-dimensional fluorescence displayed that both of the microenvironment of DHPEPN and the conformation of BSA were changed while the binding action between DHPEPN and BSA occurs.In chapter 4, the compound, DPMPEPN was synthesized and the interaction between bovine serum albumin (BSA) and DPMPEPN in Tris-HCl buffer solution (pH 7.40) is investigated using fluorescence and UV-vis absorption spectrometry. The mechanism of BSA's fluorescence quenched by DPMPEPN was dynamic quenching according to the Stern-Volmer equation. DPMPEPN's excitation and emission wavelengths were 460 and 650 nm respectively, which showed that it was a good probe for biological system. The distance between BSA and DPMPEPN was estimated as 2.96 nm based on the Forster resonance energy transfer (FRET) theory. The spectral changes of synchronous fluorescence and three-dimensional fluorescence displayed that both of the microenvironment of DPMPEPN and the conformation of BSA are changed while the binding action between DPMPEPN and BSA occurs.