| At the present time, one of the disquisitive emphases in life science is theinteraction between biomolecule and pharmic molecule and the determinationsof biomolecules. The content of some biomolecule is useful in the diagnosis ofrelated diseases. Therefore the analyses of the familiar clinic guide line arewidely regarded. However, the reagents of some existing diagnostic method inclinic are costly, the experimental conditions are strict and the procedures arecomplicated. It is significant to develop a simple and easy-operate method todetermine biomolecule.Lecithin is the most common natural phospholipids and is widespread inpropagation world. It is the main component of biological membrane and themain source of choline and aliphatic acid. It plays an important role in leavingcaducity and curing heart-vein diseases. The content of lecithin is referenced inclinic diagnosis. Establishing an easy, sensitive and effective method todetermine lecithin has significant meaning in clinic.Bile acids are the major components of bile. Bile acid serve manyimportant physiological functions, including cholesterol homeostasis, lipidabsorption, and gall-stone formation. Any pathologic process causing thedamnification of hepatic cell, such as hepatitis, hepatocirrhosis and fatty liver,may induce the decline of biological function and the raise of the concentrationof bile acid. Therefore bile acid analysis may be useful in the evaluation of liveror intestinal functions and in the diagnosis of related diseases.Lysozyme is formed by 129 tactic amino residue. Its favorable cooperativeand synergistic actions with antibiotics have a very important practically valuein medicine area. So, studies on the interactions between drugs and lysozyme indifferent aspects have a very important meaning on realizing the transport andmetabolism process of the drugs, the relation of structure and function oflysozyme, and the chemical essence of the interaction betweenbiomacromolecule and small molecule.Bilirubin is a product of heme degradation and the main component ofcreatural gall-stone. It plays an important role in creatural metabolism. It is aninner antioxidant and has active function in the regeneration of liver cell. Manydiseases may induce the raise of the concentration of bilirubin. Therefore, thedetermination of the concentration of blirubin is one of the important problemsin clinic.In this paper, using molecule spectroscopy (fluorescence and UVspectroscopy) as research instrument and tetracycline analogues-europium ionbinary complex as fluorescence probe, we study the interaction betweendrug-metal ion complex and biomolecule and its application. The relatedantibiotic drugs are tetracycline, oxytetracycline, doxycycline and methacycline.We investigated the interactions between lysome and the mentioned antibioticdrugs. Using tetracycline analogues-europium ion as fluorescence probe, wedetermined lecithin, bile acid and bilirubin, respectively and provided afluorescence analysis method to determine these biomolecule. There are fivechapters.In the first section, we summarized my thesis and introduced theinvestigation actuality of fremdness and homeland.In the second section, we provided a method to determine lecithin usingtetracycline analogues-europium ion as fluorescence probes. Tetracyclineanalogues contain the β-diketonate configuration and it is the ideal ligand foreuropium ion. The tetracycline analogues-europium ion binary complex emitsthe characteristic peak of europium ion at 612 nm. In a certain acidity condition,lecithin can remarkably enhance the fluorescence intensity of the tetracyclineanalogues-europium ion complex at λ=612nm and the enhanced fluorescenceintensity of europium ion is in proportion to the concentration of lecithin.Optimum conditions for the determination of lecithin were also investigated. Itcan be successfully applied to the determination of lecithin in serum samples.Moreover, the enhancement mechanism of the fluorescence intensity in thetetracycline analogues-europium ion system and the tetracyclineanalogues-europium ion -lecithin system is also discussed.In the third section, we studied the interaction between bile acid andtetracycline analogues-europium ion and the determination of bile acid. In acertain acidity condition, bile acid can remarkably reduce the fluorescenceintensity of the tetracycline analogues-europium ion complex at λ=612nm andthe reduced fluorescence intensity of europium ion is in proportion to theconcentration of bile acid. This method can be successfully applied to assessbile acid in serum samples.In the fourth section, the interactions between tetracycline analogues andlysozyme were studied by using UV-visible absorption and spectrofluorimetricmethod. Tetracycline analogues can make lysozyme's fluorescence quenching.The quenching mechanism is static quenching. The binding constants oftetracycline analogues with lysozyme were obtained at various temperatures.According to the F?rster nonradiative energy transfer theory, we can get thedistances of donators and acceptors. We also determined the main acting forcebetween them is electrostatic graritation according to the thermodynamicparameter.In the fifth section, using oxytetracycline -europium ion as fluorescenceprobe, a fluorescence method to determine bilirubin was provided. Thefluorescence emission spectra showed that bilirubin can remarkably reduce thefluorescence intensity of the oxytetracycline -europium ion binary complex atλ=612nm;the reduced fluorescence intensity of europium ion is proportional tothe concentration of bilirubin. We also discussed binding ability and reactionmechanism between oxytetracycline -europium ion and bilirubin. The standardcurve method was used to determine bilirubin in serum samples. Every serumsamples was determined by both a stranded method (the J-G method, which isthe most widely used clinical technique) and the developed method. Thecontents were basically accordant and the results were satisfactory.
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