Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 132-151).

Thesis (M.S.)--Montana State University--Bozeman, 2004. / Typescript. Chairperson, Graduate Committee: Mary J. Cloninger. Includes bibliographical references (leaves 133-138).

Thesis (M.S.)--Brock University, 2005. / Includes bibliographical references (leaves 68-85). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

O presente trabalho descreve o uso de carboidratos como materiais de partida para a preparação de catalisadores quirais e também de substratos quirais. Primeiramente estudos envolvendo a aplicação de amino álcoois derivados de carboidratos na arilação assimétrica de aldeídos, usando ácidos arilborônicos como fontes de grupos arila transferíveis, revelaram que um ligante preparado a partir da D-xilose mostrou-se bastante eficiente e conduziu aos produtos em excelentes rendimentos e altos excessos enantioméricos. Posteriormente a arilação de aldeídos derivados de carboidratos é descrita. Em alguns casos diastereosseletividades maiores que 20:1 foram observadas e a metodologia foi aplicada a síntese total da 7-epi-goniofufurona e análogos. / The work described herein is centered on the use of carbohydrates as starting materials for the synthesis of chiral ligands and chiral sugar-derivatives. Initially, chiral amino alcohols were studied as ligands for the asymmetric arylation of aldehydes using aryl boronic acids as the source of transferable aryl groups. We found that a chiral ligand derived from D-xylose was very efficient and the desired products were obtained in excellent yields and enantiomeric excesses. In addition, the arylation of sugar-based aldehydes was also studied. In many cases, excellent diastereoselectivities of >20:1 were achieved and the methodology was employed in the total synthesis of 7-epi-goniofufurone and analogues.

D.Sc. (Chemistry) / The aim of this study was to develop new methodology for the transformation of unsaturated carbohydrates utilising organometallic compounds. The first half of the study was directed toward developing a general synthesis of complex allyltins and in determining their application to carbon-carbon bond formation. It was decided to utilise carbohydrate substrates in this regard to develop a novel method of producing glycosides...

D.Sc. (Chemistry) / The aim of this study was directed towards the stereo- and regiospecific introduction of carbon nucleophiles onto the 1- and 4-positions of glycopyranosides, since these chiral molecules contain the tetrahidropyran skeleton of a wide range of biologically active compounds (example the carpenter bee pheromone or the civit cat pheromone) or substructures of more complex natural products, such as the ionophore antibiotics indanomycin and zincophorin. Two appraoches for the introduction of carbon substituents onto the 1- and/or 4-positions of unsaturated glycopyranosides were investigated ...

Diabetes is a chronic, complex illness with a risk for acute and long-term complications. The aim of this quality improvement project on prevention of type 2 diabetes was to increase self-management behaviors in patients at high risk of type 2 diabetes, decrease the financial burden of type 2 diabetes, and decrease the incidence of complications that can occur from type 2 diabetes. The primary outcome of this project was each participant reporting at least one lifestyle modification that would be helpful in preventing type 2 diabetes after attending two group education sessions. A pretest posttest design was used for this project. Three completed the initial questionnaires, and two attended the educational sessions and completed the posttest questionnaires. Of the total number of participants, one reported a decrease in hot/cold cereal, regular soda, sugar or honey in coffee/tea, other potatoes, tomato sauces, chocolate, doughnuts, and cookies, cake, pies, brownies. Two participants reported a decrease in fruit juice, fried potatoes, and pizza. One participant had an increase in physical activity while the other participant had no change in physical activity. The landmark Diabetes Prevention Program (DPP) Trial demonstrated that counseling on a healthy diet and moderate physical activity reduced the incidence of type 2 diabetes. The two participants in this project reported they made some helpful changes in diet after two education sessions. It is vital to the success of a prevention program to convey the significance of preventing a chronic disease such as type 2 diabetes

Sugar complexes with anions and cations are reviewed. Evidence is presented for the formation of a complex of stoichiometry 1:1 in aqueous solution between methyl-α-Dglucopyranoside and magnesium perchlorate. The complex may be detected by the method of continuous variations. Measurements of changes in the proton chemical shifts of the glucoside in dauterium oxide, indicate that the complex is probably formed between the vicinal hydroxyl groups at C-2 and C-3 of the pyranoside ring and the hydrated cation. At elevation temperatures there is evidence for the presence of a complex of stoichiometry 2:1. Experiments conducted on cellulose indicate the possible formation of cellulose - magnesium-ion complexes . These complexes provide an explanation for the "protective action" of mEgnesium compounds on the cellulose portion of pulp during alkali-oxygen bleaching.

A major problem associated with cellular cryopreservation is the recovery of cellular viability upon thawing. Current cryopreservation techniques use additives such as DMSO, sucrose and fetal bovine serum. However, each have their own respective cytotoxic issues. A significant factor in cryotoxicity is the formation of large ice crystals which can damage cellular components and cause dehydration. This has significant impacts for applications such as food preservation, scientific research, and tissue preservation. To this end, our laboratory is interested in synthesizing biologically-relevant compounds that can act as cryoprotectants by preventing the formation of large ice crystals in sub-zero temperatures. Our lab has previously synthesized structural analogues of native antifreeze glycoproteins (AFGPs, found in the blood of Antarctic cod), that possess the unique ability to inhibit ice-recrystallization. However, the mechanism by which they inhibit ice recrystallization is unclear. This thesis focuses on efforts made to understand this mechanism, and synthesize molecules that are more potent in ice recrystallization inhibition (IRI) activity compared to previously synthesized analogues. By assessing the IRI activity of various mono- and disaccharides, we have shown that the density of water molecules that surround a carbohydrate (Hydration Index) is directly proportional to the ability of sugars to inhibit ice crystal growth. In an effort to design functional AFGP analogues, various C-linked analogues were synthesized that contained different spacer lengths between the carbohydrate and the peptide backbone. Analyses of the solution conformations of these analogues showed that IRI-active AFGP analogues contain a distinct conformation in which the carbohydrate is oriented to form a hydrophobic pocket with the side chain. We hypothesize that this change in glycoconjugate hydration is responsible for disturbing its surrounding waters, thereby preventing water from adding to the ice lattice required for ice growth. Finally, SAR studies showed that threonine-containing AFGP and antifreeze proteins are more potent in antifreeze activity than serine-containing analogues. As the most potent AFGP analogue previously synthesized by our lab contains a C-linked-α-galactosyl -serine residue, we hypothesized that the analogous glycopeptide containing a C-α-galactosyl-threonine residue will be more potent in antifreeze activity. The final section describes efforts to synthesize a C-linked α-galactosyl-threonine glycoconjugate.

The ¹H and ¹⁹F nuclear magnetic resonance (n.m.r.) spectra of a series of hexopyranosyl and pentopyranosyl fluorides were examined in some detail. The ¹H n.m.r. analyses (first order) enabled the gross molecular conformations to be determined and at the same time provided an opportunity to check the anomeric assignments previously made through application of other techniques. The¹⁹F n.m.r. parameters were then considered and several steric dependencies were observed. The ¹⁹F chemical shifts are controlled, in part, by the spatial orientation of the fluorine, but also, by the orientation of remote acetate groups or other substituents. Rules were subsequently developed for predicting the ¹⁹F chemical shifts for axial fluorines attached to C₁ of a pyranose carbohydrate. These rules were used to predict the ¹⁹F chemical shifts of the remaining "rare" giycopyranosyl fluorides. It was also noted that the ¹⁹F-¹H couplings resemble the ¹H-¹H couplings in that J(trans) > J(gauche). Moreover these ¹⁹F-¹H couplings are several times larger than the corresponding ¹H-¹H couplings and are also more sensitive to their precise steric environment. This study led to the observation that the β-D-anomers of the pentopyranosyl fluorides exist in the alternate chair form (¹C₄), which allows the fluorine atom to adopt an axial orientation. Subsequent to these initial n.m.r. investigations, a new reaction sequence was developed for the addition of "XF" to alkenes, Whereas this reaction sequence (AgF and X₂) results only in trans addition to cyclohexene (courtesy of D.L. Jones); it results in both cis and trans additions to cyclic vinyl ethers, although the trans adduct(s) always predominate: a possible reaction mechanism is discussed. This reaction sequence (X = I, Br,CI) was first applied successfully to D-glucal triacetate and then extended to other α,β-unsaturated cyclic ethers. The reaction products to D-glucal triacetate were for the most part crystalline. These 2-deoxy-2-halo-D-hexo-pyranosyl fluorides proved to be excellent models for extending previously observed electronegative dependencies. Moreover, when related to the 2-deoxy-D-glycopyranosyl fluorides, these compounds revealed that the orientation of remote substituents must play an important role in - determining ¹⁹F chemical shifts. Finally, a brief introduction is given to the utilization of both the "selective irradiation" and the "spin-tickling" methods for determining the relative signs of proton-proton coupling constants of carbohydrate derivatives. For most saturated carbohydrates the vicinal ¹H-¹H couplings have been found to be positive and the geminal couplings are negative in sign. For unsaturated derivatives both vicinal and geminal couplings are positive. The signs of the couplings of an episulphide derivative are the same as those of the saturated carbohydrates, whereas, the signs for an epoxide resemble those of unsaturated carbohydrates. These findings arc in accord with previous experimental and theoretical results. It has been demonstrated that the signs of long-range ( ⁴J) couplings of saturated derivatives exhibit a regular stereospecificity: those between two equatorially oriented protons (⁴ J, ₑ,ₑ) being positive and those between an axial and an equatorial proton (⁴Jₑ,ₐ ) being negative in sign. These findings are contrasted with the previous theoretical predictions and their potential as an adjunct to stereochemical studies is discussed. For unsaturated carbohydrate derivatives the long-range couplings are all negative in sign. The "selective irradiation" and "spin-tickling" homonuclear magnetic double resonance (n.m.d.r.) techniques have been used to determine the relative signs of the vicinal and geminal ¹⁹F- ¹H couplings of a series of glycopyranosyl fluorides. In all cases these two couplings have the same relative signs. Heteronuclear decoupling experiments on 2-bromo-2-deoxy-α-D-mannopyranosyl fluoride triacetate showed that for this derivative the vicinal coupling between H₁ and H₂ and the geminal coupling between H₁ and F₁ have the same relative signs. On this basis an absolute positive sign was assigned to both vicinal and geminal ¹⁹F- ¹H couplings. / Science, Faculty of / Chemistry, Department of / Graduate