Design, Synthesis And Analytical Application Of Highly Selective Reactive ~-OCl Fluorescent Probes

The active oxygen(ROS) in the body is the main factor that leads to various diseases. Hypochlorite, as one of the active oxygen, is a derivative in the macrophages of the body. In general, the application concentration of hypochlorite varies from 10-5to 10-2 M. However, high concentration of hypochlorite will produce adverse effect to human and animals. Excessive production of hypochlorite could lead to infection,lung damage, for example, rheumatoid arthritis, kidney disease, etc. In addition,hypochlorite has remedial effect to neural degenerative disease, Parkinson's disease and cerebral hemorrhage. Hypochlorite can promote the mitochondria, lysosomes capture. Hypochlorite, which reacts with a series of biological molecules, can control the pathogen's invading and a variety of disorder disease. Because hypochlorite plays an important role in various physiological and pathological processes, realizing the identification and detection of hypochlorite has become a challenging frontiers in chemical subject development.However, the detection of hypochlorite has many difficulties because hypochlorite has low concentrations and short life in the human body and is strongly oxidizing. The detection of hypochlorite has low sensitivity, poor selectivity. Small molecule fluorescent probes detecting hypochlorite are mainly b classified as turn-on fluorescence probes and ratio fluorescence probes. It is difficult to remove the fluorescence background and the distribution of turn-on fluorescence probes. It brings great inconvenience to the quantitative determination. Ratio fluorescent probe has emission peak at different wavelengths and avoids the influence of the background fluorescence, and expands the dynamic range of fluorescence measurement.In this thesis, a new response group was used for detecting hypochlorite, which has not been reported in small molecule fluorescence probe. After treating with hypochlorite, the oxime and propargyl at ortho position took place a cyclization reaction to afford the ?-extended derivatives.(1) Based on propargyl and oxime groups, we design and synthesis a probe which has naphthol as fluorophore for specific detecting hypochlorite. Mass spectrometry verified that, after treated by the hypochlorite, propargyl and oxime cancyclize. The selectivity to the hypochlorite is verified by interference tests. On the basis of the mechanism, a coumarin-based fluorescent probe detecting hypochlorite was synthesized. The background fluorescence of the probe is very low, and under the action of hypochlorite, the fluorescence intensity increases about 60 times. It has high sensitivity, good selectivity with the detection limit of 38 nM. In the range of 0-100?M hypochlorite, the action of fluorescence intensity increases with the concentration and it show good linear. The linear equation is F = 5132.84 + 1643.64 [~-OCl] ?M, R= 0.9938. Moreover the probe has good light stability and is not sensitive to pH changes.(2) On the basis of the above mechanism, a fluorescein-based probe was synthesized to detect hypochlorite. The excitation wavelength and the emission wavelength were at 490 nm and 530 nm respectively. Under the action of 5 equiv hypochlorite the fluorescence intensity increased 10 times. It has high sensitivity,good selectivity. In the range of 0-40 ?M hypochlorite, the fluorescence intensity increases with the concentration and it show good linear. The linear equation is F =1640.49 + 245.13 [~-OCl] ?M, R = 0.9960. The probe has been used for imaging the cells endogenous hypochlorite and exogenous hypochlorite.