Study By Fluorescence Probe Based On The Interaction Between Cucurbit[7]uril And Some Drug Molecules

Cucurbit[7]uril is a low polymer of alms bowl shaped that its ports is ringent.Cucurbit[7]uril is often used as the carrier of supramolecular self assembly and the sensor because of its good water solubility,rigid symmetrical structure and molecular recognition properties.The cucurbit[7]uril's hydrophobic cavity can capsule many guest molecules,such as small drug molecules,organic molecules,nano materials,etc.In this paper,we established a spectrum analysis method for the determination of non-fluorescence drug molecules with the help of two fluorescent probes of cucurbit[7]uril-palmatine and cucurbit[7]uril-berberine,studying on the interaction between cucurbit[7]uril and some drug molecules,observing that these drug molecules can produce fluorescence quenching effect on the fluorescence probe,and it was showed a good linear relationship between the drug concentration and the fluorescence quenching rate.By density functional theory,molecular model calculation and NMR,it was further confirmed that cucurbit[7]uril capsuled drug molecules.We established the fluorescence analysis method for the determination of phenformin,guanethidine and itopride.The research results of this thesis are based on the outstanding achievements of cucurbit[7]uril researchers and the work of our group,and studying the molecular recognition and competitive inclusionmain between cucurbit[7]uril and three kinds of drugs molecules(phenformin,guanethidine,itopride)by fluorescence probe technique.In the reported literature,the three drug guest molecules haved been determinated by high performance liquid chromatography(HPLC),capillary electrophoresis(CE),chemiluminescence(CL)and gas chromatography(GC)method,however it have not been researched by fluorescent probe method.In this paper,in view of the good water-solubility of cucurbit[7]uril and strong association ability with three kinds of guest molecules,studying the clathration between CB[7] and three kinds of drug moleculars by fluorescence probe method,NMR,UV-Vis,molecular model,theoretical calculation analysis method.Based on the mechanism of interaction between host and guest,a fluorescent probe method was developed for the quantitative determination of drug guest molecules by fluorescence quenching.The research contents of this paper are as follows:Chapter 1 : The article describes the related contents of supramolecular chemistry,supramolecular interactions,host guest chemistry and molecular recognition;Citing an example,and mapping the application of cucurbit[7]uril in these areas;Summarizing the contents of this paper.Chapter 2 : In aqueous solution,we determined the phenformin hydrochloride(PFH)with the help of CB[7]-PAL fluorescent probe.The CB[7]-PAL fluorescent probe has strong fluorescence signal.PFH can extrude PAL out of the CB[7] cavity because of the strong binding capacity of PFH,causing the fluorescence quenching of probe.In aqueous solution,it shows the good linear relationship between the concentration of phenformin(C)and the value of fluorescence quenching((35)F)in the range of 0.005 ?g m L-1 to 1.9 ?g m L-1 with the limit of detection of 0.003 ?g m L-1.Based on the work,fluorescence analysis method was established for the determination of trace amounts of phenformin hydrochloride.Meanwhile,the mechanism between guest molecular and probe was discussed by theoretical calculation of molecular model and NMR.Chapter 3 : The clathration between guanethidine and fluorescent probe was studied by fluorescence spectrum.GTD can extrude PAL out of the CB[7] cavity,causing the fluorescence quenching of probe.The reason is that CB[7]-GTD was more stable than CB[7]-PAL.In aqueous solution,it shows the good linear relationship between the concentration of phenformin(C)and the value of fluorescence quenching((35)F)in the range of 0.022 ?g m L-1 to 4.947 ?g m L-1.Therefore,the method can be applied to the determination of trace amounts of guanethidine.At the same time,the spectral signature was studied by UV-vis.Chapter 4 : The fluorescence signal was determined between itopride and cucurbit[7]uril-berberine(CB[7]-BER)by fluorescence spectrum.Under the optimized experimental conditions,itopride may reduce the fluorescence intensity of the probe system.