Thesis (PH. D.)--Columbia University, 1923. / Vita. Description based on print version record.

Thesis (Ph. D.)--Columbia University, 1925. / Cover title. Vita. Description based on print version record.

Within the past few decades, interest in the field of aminosugar chemistry has been stimulated to a remarkable degree and the discovery and syntheses of a wide range of new aminosugars of differing types, for example of two monoamino-tetroses (12,19), nineteen monoamino-pentoses, two diamino-pentoses, thirty-three monoamino-hexoses, and eighteen diamino-hexoses (20) have been accomplished. It is well undterstood that the aminosugars, significant constituents in mnay biologically important materials (11), consist of substances that may be regarded a teh condesation products of an amine and a carbohydrate. Falling into this category are the 2-amino-hexoses which may be derived conceptually as the condensation of ammonia with carbon atom number 2 or a hexose. (4). Thus, D-glucose is the conceptual parent of D-glucosamine (i.e., 2-amino-2-deoxy-D-Glucose). D-allosamine is one of the rarer aminosugars about which very little is know concerning chemical properties and derivatives. A few studies have recently been made on the beta series of benzyl D-allosaminides after it was shown by Gross et al. (5) that the use of benzyl N-benzoyl-4, 6-0-benzylidene-β-D-glucosaminide as an intermediate in the synthesis of D-allosamine derivative proved fruitful for large-scale preparation of the β-D-allosaminide derivatives. This basic work has established conditions which have made it possible and desireable to conduct also an investigatin into the chemistry of the alpha series of D-allosaminides. Thus it appeared that a procedure involving the benzyl N-benzoyl-α-D-glucosaminide might well afford the alpha anomeric D-allosaminides. Although several benzyl N-benzoyl-hexosaminides are known (1,5,20), no information is yet available in the literature about benzyl N-benzoyl-α-D-glucosaminide from the standpoint of chemical properties and derivatives. To explore processes from making derivatives of D-allosamine particularly in the series of alpha-anomers, it is necessary to investigate the chemistry of benzyl N-benzoyl-α-D-glucosaminide and its derivatives, preparatory to an attempt to enter the alphaseries of D-allosaminides. Therefore, the principal interest of this investigation was to prepare and to investigate properties of benzyl N-benzoyl-α-D-glucosaminide and its derivatives, and to explore its utility as a possible precursor for the preparation of benzyl 3-0-benzoyl-α-D-allosaminide hydrochloride by the method analogous to the synthesis of the corresponding beta-anomer.

No description available.

Kinetic isotope effect (KIE) study of enzymatic mechanisms has the potential for aiding the design of tight binding inhibitors, but is hampered by the need for isotopically labeled substrates. Recently, however, methods for measuring ¹³C and ²H KIEs at natural abundance by NMR spectroscopy have been developed, allowing KIEs to be measured at every NMR resolvable nucleus without isotopic substitution. Until this study, this technique had yet to be applied to an enzymatic system. KIEs provide information about transition states (TS) and since enzymes tightly bind structures resembling the TS, TS analogs can be used as powerful inhibitors and potential drugs. Glycosidases are enzymes that hydrolyze the acetals of carbohydrates. Inhibition of glycosidases has a large potential for therapeutic value. Methyl glucoside hydrolysis was used as a model substrate in the measurement of natural abundance KIEs. ¹³C KIEs were successfully measured on the acid and glucosidase catalyzed hydrolysis of methyl glucosides. The values of the primary ¹³C KIEs show that hydrolysis of β-methyl glucoside by β-glucosidase a more concerted ANON reaction. KIEs on the corresponding α-anomer suggest the opposite result, a ON*AN reaction. The experimental KIEs also matched well with calculated equilibrium isotope effects, lending support for the accuracy of the measurements. / Thesis / Master of Science (MSc)

Thèse (M.Ress.Renouv.) -- Université du Québec à Chicoutimi, 2004. / Bibliogr.: f. [124]-136. Document électronique également accessible en format PDF. CaQCU

There were two main purposes to this study. The first was to determine the vitamin B-6 and pyridoxine β-glucoside content of selected foods commonly consumed in Malawi. The second was to examine the effect of preparation procedures of foods in Malawi on the content of vitamin B-6 and pyridoxine β- glucoside in foods. Seventeen plant foods commonly eaten in Malawi were determined for vitamin B-6 and pyridoxine β-glucoside using a microbiological assay. In addition, two commercial weaning foods, roasted maize-soy bean blend and extruded maize-soy bean blend, were also determined for vitamin B-6 and pyridoxine β-glucoside contents. Among all the foods analyzed, whole maize flour contained the highest amount of vitamin B-6 (0.66 mg/100 g), therefore, an excellent source of vitamin B-6 content in foods. Cooking decreased vitamin B-6 in pinto beans, kidney beans, sugar beans and cow peas by 34%, 45%, 14% and 48%, respectively. Roasting decreased vitamin B-6 in chick peas and soy beans by 59% and 38%, respectively. Soaking and fermentation reduced vitamin B-6 in soaked maize flour and cassava flour by 86% and 89 %, respectively. Therefore, these data suggest that some of the preparation procedures practiced in Malawi have a negative impact on the vitamin B-6 content of the processed foods. Cooked and roasted foods contained lower total amount of pyridoxine-glucoside than that of the raw food. The high pyridoxine β-glucoside content have adverse impact on the bioavailability of vitamin B-6 content. Based on typical diets for the urban and rural populations in Malawi, the rural diet contained less vitamin B-6 compared to that of urban diet. Therefore, the rural population may be at risk of inadequate vitamin B-6 intake compared to the urban population. / Graduation date: 2002

No description available.

No description available.

The purpose of this work was the preparation of specifically blocked D-glucose derivatives with a free hydroxyl group on the anomeric carbon (C-1).