Research Of Molecular Assembly And Biological Applications Of Cyclodextrin Derivatives

Supramolecular chemistry examines the weak and reversible noncovalent interactions between molecules, and is a topic of general interest in the field of food, medicine, energy, agriculture, materials, enviromental protection and so on. Cyclodextrin, as an important macrocycle host molecule in supramolecular chemistry, was widely studied and used in the field of medicine due to its unique structure, biological compatibility, low-toxicity and ease of preparation. The derivatization of cyclodextrin can change and improve its solubility, stability and the ability to form inclusion complexes. Based on that, a series of cyclodextrin derivatives have been designed and synthesized. Their recognition ability and assembly behaviors with some organic compounds and polymers have been studied. Beyond this, the biologic applications of these cyclodextrin derivatives based supramolecular complexes have been explored. The major contents of this thesis are as follows:1. The general aspect of the research histroy and current developing situation of supramolecular chemistry were described in brief. The sturcture, properties, new progress and important achievements on derivation, molecular recongnition, moleculrar assembly and applications of cylodextrin were reviewed.2. Two cyclodextrin derivates per-6-deoxy-6-(1-methylimidazol-3-ium-3-yl)-β-cyclodextrin and mono-6-deoxy-6-(1-methylimidazol-3-ium-3-yl)-β-cyclodextrin were designed and synthesized. Their induced aggregation behaviors towards two anionic surfactants were fully investigated. The results indicated that the hepta-imidazoliumyl-β-cyclodextrin can induced aggregation of anionic surfactants at concentration far lower than their original critical aggregation concentrations. The morphology and thermal stability of the induced supramolaculer aggregates were characterized by means of UV-vis spectroscopy, dynamic light scattering, and transmission electron microscopy.3. A non-toxic supramolecular nanoparticle is composed of β-cyclodextrins modifed gold nanoparticle and anthryl-modified adamantanes was designed and constructed. The stracture and morphology of this supramolecular nanoparticle were fully investigated by means of Uv-vis spectroscopy, fluorescence spectroscopy, NMR, thermal gravimetric analysis, transmission electron microscopy and atomic force microscopy. In consideration of that anthryl grafts can intercalate in DNA duplex, this supramolecular nanoparticle showed efficiently condensation abilities to plasmid pBR322DNA and calf thymus DNA. Interesitngly, the DNA condensation efficiency of this supramolecular nanoparticle could be conveniently tuned by changing the stoichiometry ratio between host and guest.4. A polysaccharide porphyrin supramolecular conjugates were consturcted form Zinc porphyrin modifed β-cyclodextrin and hyaluronate modifed adamantane. The composition of the supramolecular conjugates were characterized by NMR, infrared spectroscopy, mass spectroscopy and elemental analysis. Due to their porous structures, the supramolecular conjugates can efficiently capture fullerenes with in the hydrophobic holes formed by triphenyl zinc porphyrins. The C60capture behaviour of porphyrin modifiedβ-cyclodextrin and supramolecular conjugates were characterized by spectroscopy and microscopy. The cyclodextrin/hyaluronate/C6o conjugate displays a satisfactory DNA-cleavage ability under the visible-light irradiation.