Studies On The Interaction Of Cucurbituril With Some Drug Molecules

III Cucurbituril is a kind of new supramolecular macro ring compound,because of thespecial structure of cucurbituril,researchers pay amount attention on it.Cucurbituril has a wide range of applications including molecular recognition,self-assembly,drug delivery and sensors.In this paper,the interaction between cucurbit[7]uril and drugs was confirmed via the fluorescence spectroscopy,fourier-transformation-infrared spectroscopy,differential scanning calorimetry,x-ray diffraction,and1 H NMR spectrum.It is elaborated formation mechanism of inclusion complexes by means of experimental and theoretical methods that provide a theoretical basis for the application of drugs to improve bioavailability,enhance the solubility,and reduced toxicity.The content of this paper is as follows:1.The history of the development of supramolecular chemistry was described briefly.This thesis described the origin,synthesis and characteristics of cucurbituril in detail.An introduction of the development of cucurbituril on molecular recognition and pharmaceutical analysis.Our design was also put through according to the previous experiences.2.The supramolecular interaction between cucurbit[7]uril(CB[7])and camptothecin(CPT)was studied by fluorescence spectroscopy,differential scanning calorimetry,X-ray diffraction(XRD)and fourier transformation-infrared spectroscopy(FI-IR),1H NMR was further employed to study the formation mechanism of the complexes.The formation of 1:2complex with CB[7] in aqueous solution was confirmed by fluorescence spectroscopy and the apparent stability constant was 3.95 × 1012 L2 mol–2.The formation mechanism of the complex was studied using spectrofluorimetry,1H NMR and molecular modeling calculations.In aqueous solution,the relative fluorescence intensity of CPT with CB[7] was then measured at 521 nm with excitation at 404 nm,a linear relationship was obtained in the range from0.007 to 0.31 μg mL-1 with a detection limit of 2 ng mL–1.The correlation coefficient was0.9994.While in human plasma,no obvious interaction between CB[7] and CPT was observed,which may be due to the fact that CPT preferentially binds human serum albuminthan CB[7].Here,we report a camptothecin delivery carrier based on cucurbit[7]uril supramolecular inclusion,which can uniformly disperse camptothecin into water and and increase the aqueous solubility greatly.3.The supramolecular interaction between cucurbit[7]uril(CB[7])and methotrexate(MTX)was studied by UV-visible absorption spectra,1H NMR,2D NOESY,and theoretical calculations.Our experimental results confirm the formation of 1:2 inclusion complexes with CB[7],and proposed a simple and sensitive competitive method for fluorescence detection of MTX.It was found that the fluorescence intensity of CB[7]-palmatine,CB[7]-berberine and CB[7]-coptisine quenched linearly upon the addition of MTX.Linear ranges obtained in the detection of MTX were 0.1–15 μg mL–1,0.2–15 μg mL–1,and 0.4–15 μg mL–1with detection limits of 0.03 μg mL–1,0.06 μg mL–1,and 0.13 μg mL–1,respectively.This method can be used for the determination of methotrexate in biological fluids.These results suggest that cucurbit[7]uril are promising drug carriers for targeted methotrexate delivery and monitoring,with improved antitumor efficacy and reduced toxicity in normal tissues.4.The preparation methods of magnetic perhydroxy-cucurbit[6]uril were studied,and the specific conditions of perhydroxy-cucurbit[6]uril were explored,at the same time,the adsorption capacity of perhydroxy-cucurbit[6]uril was explored.