| This dissertation describes the breadth of work that I have accomplished from the year 1998 until present. It encompasses a plethora of organic and enzymatic reactions directed at the understanding of carbohydrates and their interaction with proteins.; Chapter 1 examines how modified carbohydrates can interact with both a transferase enzyme, namely α-galactosyltransferase, and an antibody, namely anti αGal antibody. It was discovered that αGal analogues, depending on the position of modification, would not vary significantly in the protein's ability to recognize them. The results presented show promise for further studies that can be directed at antibody/epitope binding of carbohydrates.; Chapter 2 examines the feasibility of synthesizing β-D-1- O-hydroxylamino carbohydrate polymers mediated by galactose oxidase. The polymerization of monomeric carbohydrate units presents difficult challenges largely as a result of chemo-selectivity problems. Our approach takes maximum advantage of the high regio-selectivity and environmentally benign nature of enzymatically catalyzed reactions. Galactose oxidase selectively oxidized the C6-CH2OH unit of hydroxylamino galactose derivatives to the corresponding aldehyde, producing a difunctional aldehyde-hydroxylamine unit while undergoing simultaneous condensation polymerization in situ.; Chapter 3 describes how monosaccharides, when derivatized with appropriate appendages, can be used as starting materials to synthesize potent inhibitors. Galactose oxidase converted the C6-primary hydroxyl moiety of D-galactopyranosides to hydrated aldehydes. Dehydratative coupling with hydroxylamines produced oximes, which, under the conditions of hydrogenolysis, gave rise to polyhydroxyazepanes.; Chapter 4 describes the simple yet elegant synthesis of chiral 2,6-dideoxysugars from achiral molecules. An efficient synthesis of β,γ-unsaturated δ-lactones was achieved through the process of RCM. The lactones were asymmetrically dihydroxylated, and then subjected to borohydride reduction to produce some rare 2,6-dideoxysugars. The most significant monomers synthesized were the L-sugars, found very infrequent in nature.; Chapter 5 describes the attempts at forming a nine-membered tethered intramolecular macrocycle. The purpose for the synthesis extends into bioassays, whereby the idea of increased binding affinity will be explored. |
