Characterization Of Vitamin-Cyclodextrin Supramolecule And Analytical Application

Chapter 1: Supramolecure of cyclodextrin is introduced briefly and the property and function of vitamin were summarized. At the same time, the application of cyclodextrin on vitamins and the actual state of study on interaction between cyclodextrin and vitamins were reviewed.Chapter 2: Fluorescence property of VK4 in different pH media was determined by steady-state fluorescence technology, the result suggested that VK4 hydrolyze hi alkaline condition. The fluorescence intensity of maximal emission wavelength 282nm decreased with pH growing, while fluorescence intensity of emission wavelength 473nm increased gradually. The latter peak is of the product (2-methyl-l,4-dinaphthol anion [(CH3C10H5O2)2-]) of VK4 hydrolyzing. By comparing fluorescence spectrum of the product of VK4 with that of VK4 itself in the presence of cyclodextrin, the catalytic effect of cyclodextrin on hydrolysis of VK4 was found. Based on the phenomena the mechanism of reaction between VK4 and cyclodextrin was proposed. A new method of determining VK4 was established in virtue of the hydrolytic properties of VK4. The linear range was 2.0 ×10-6-5.0×10-5 molL-1, with the detection limit of 5.0×10-7 molL-1 and RSD of 1.9%. The method was first used for the determination of VK4 in tablets. The recoveries were in the range of 99.9%-107.7%. In addition, VK4 includes with cyclodextrin in acid and neutral media.Chapter 3: The inclusion complexes of vitamin P (rutin)-β-cyclodextrin were synthesized by coprecipitation in methol/H2O. The inclusion interaction and pattern of bonding were studied by some methods including steady-state fluorescence etc.. The formation constant of complex was obtained by using unproved Benesi-Hildebrand equation and the result suggested the complex preferred 1:1 (rutin:CD) stoichiometry. Furthermore, the spatial configuration of the complex has been proposed based on NMR and molecular modeling. The phenyl of rutin locates in the cavity of β-CD, and the rest of rutin molecule resided out of the primary edge.Chapter 4: The inclusion interaction of VB2 with P-CD and its derivatives were compared by steady-state fluorescence technology. The effect of concentration of cyclodextrins on fluorescence spectra of VB2 was studied. The formation constant of complex was obtained by using double reciprocal curves and the resultsuggested the complex preferred 1:1 (VB2:CDs) stoichiometry. And the formation constants of complex (with β-CD, HP-β-CD, SBE-β-CD and CM-β-CD) is 215, 43, 270 and 208 lmol-1 respectively.Chapter 5: Inclusion of vitamin PP (including nicotinic acid and nicotinamide) and cyclodextrin was studied. Phenolphthalein was selected as competitive probe. Formation constant of phenolphthalein-cyclodextrin inclusion complex was determined by UV-vis spectra of phenolphthalein first, then vitamin PP was added into the system of phenolphthalein and cyclodextrin, and the formation constants of nicotinamide-cyclodextrins (β-cyclodextrin, HP-β-cyclodextrin and SBE-β-cyclodextrin) complexes were obtained by measuring absorption of phenolphthalein. In addtion, crystals of inclusion complexes between β-cyclodextrin and nicotinic acid (or nicotinamide) were synthesized, and were charactered by X-ray diffraction and NMR. The result showed that nicotinic acid located in the cavity of p-cyclodextrin by pattern of "shallow inclusion", and pyridine moiety of nicotinamide is located nearly at the center of the cativiry. The parametesr of crystal were obtained by X-ray diffraction and consist with the result in reference. Hydrogen bonds are the dominating force in the formation of nicotinic-β-cyclodextrin complex. In nicotinamide-β-cyclodextrin, the pyridine moiety is located nearly at the center of the cavity, while the amide group protrudes outside from the O (6) side of the cavity. The amide group forms three hydrogen bonds with symmetry-related adjacent P-cyclodextrin and water molecules. Nicotinamide molecule bonded in the host cavity by van der Waals force and hydrogen bonds. Six water molecules are distr...