Thesis(Ph.D.)--Case Western Reserve University, 2009 / Title from PDF (viewed on 2009-12-30) Department of Chemistry Includes abstract Includes bibliographical references and appendices Available online via the OhioLINK ETD Center

Reproduction de : Thèse de doctorat : Biologie et Biochimie Appliquée : Reims : 2004. / Titre provenant de l'écran titre. Bibliogr. f. 141-172.

published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

published_or_final_version / Biochemistry / Doctoral / Doctor of Philosophy

The thesis of this study describes a synthesis way to produce an alkyne equipped clickable precursor of 2-deoxy-2-fluoro-D-glucose (FDG) with a beta-configuration. This FDG-derivate is produced with a clickable link in purpose to be used in PET in vivo imaging. The product was synthesized by acetylation protection and further epoxidation on the glucose analog D-Glucal. Glycosylation occurred by electrophilic reaction of propargyl alcohol and configuration of the product was ensured during Lattrell-Dax inversion.

published_or_final_version / Zoology / Master / Master of Philosophy

No description available.

Prolactin (PRL) is a highly versatile hormone in terms of its biological functions. In Galliformes, high levels of PRL are associated with incubation behaviour and hatching. It has been shown that these high levels of PRL were associated with an increased ratio of glycosylated PRL (G-PRL) versus non-glycosylated PRL (NG-PRL) in turkey (Bedecarrats et al., 1999a). This suggests that glycosylation of PRL is related to its proper function during those stages of life. However, the mechanism(s) controlling post-translational modification of PRL are unknown. In order to investigate genes associated with the glycosylation of PRL, an in vitro study was undertaken. The pituitary glands of day 24 turkey embryos (n=60) were collected and pooled into two groups which were incubated in medium 199 for 4 hours in the absence or presence of 10-7 M vasoactive intestinal peptide (VIP). Western blot analysis of PRL was used to assess the response of the pituitary glands to the VIP stimulation. As expected, the absolute level of PRL as well as the percentage of glycosylated PRL isoform increased following stimulation with VIP. The mRNA of both stimulated and non-stimulated samples were extracted and reverse transcribed into cDNA. Using suppression subtractive hybridization (SSH), a cDNA subtractive library which only contained differentially expressed cDNAs between VIP stimulated and non-VIP stimulated turkey pituitary glands was constructed. Seventeen percent of the genes from the library are related to cell proliferation and apoptosis. Ten genes were selected for real-time PCR analysis. The functions of these genes and their potential roles in response to the stimulation by VIP and glycosylation of PRL are discussed.

The realization that oligosaccharides play a central role in many biological processes has led to increasing interest in the preparation of synthetic targets for use in medical or biochemical research and drug discovery. The preparation of oligosaccharides from simple carbohydrate derivatives requires efficient methods for the construction of O-glycosidic bonds. Much effort has been made towards the development of selective methods for the preparation of oligosaccharide targets. The most common method to overcome the challenge of regioselectivity is the use of protecting group manipulations to suppress glycosylation at undesired positions. This is highly inefficient in terms of atom and step economy. Organoboron catalysis is a recent strategy that imparts regioselective activation of the equatorial hydroxy group of cis-vicinal diols towards functionalization. Following the initial findings that diarylborinic acid catalyzes the regioselective acylation of carbohydrate derivatives, an analogous method for regioselective glycosylation under Koenigs-Knorr conditions has been developed.

The realization that oligosaccharides play a central role in many biological processes has led to increasing interest in the preparation of synthetic targets for use in medical or biochemical research and drug discovery. The preparation of oligosaccharides from simple carbohydrate derivatives requires efficient methods for the construction of O-glycosidic bonds. Much effort has been made towards the development of selective methods for the preparation of oligosaccharide targets. The most common method to overcome the challenge of regioselectivity is the use of protecting group manipulations to suppress glycosylation at undesired positions. This is highly inefficient in terms of atom and step economy. Organoboron catalysis is a recent strategy that imparts regioselective activation of the equatorial hydroxy group of cis-vicinal diols towards functionalization. Following the initial findings that diarylborinic acid catalyzes the regioselective acylation of carbohydrate derivatives, an analogous method for regioselective glycosylation under Koenigs-Knorr conditions has been developed.