Spironucleosides are a type of conformationally restricted nucleoside analogs in which the anomeric carbon belongs simultaneously to the sugar moiety and to the base unit. This locks the nucleic base in a specific orientation around the N-glycosidic bond, imposing restrictions on the flexibility of the sugar moiety. Anomeric spiro-functionalized nucleosides have gained considerable importance w...

The crystal structure of the title compound, C(30)H(38)N(2)O(5)Si, has been investigated to establish the relative stereochemistry at the spiro ring junction and the two anomeric centres. Each of the O atoms in the tetra-hydro-pyran rings adopts an axial position on the neighbouring ring. This bis--diaxial conformation is adopted, thus gaining maximum stablization from the anomeric effect. The ...

Conflicting data have been reported concerning the anomeric specificity of glucokinase. In the present study, liver hexokinase (Km for D-glucose 0.4 mM) displayed a higher affinity for but lower Vmax. with alpha- than with beta-D-glucose. The velocity of the reaction catalysed by liver glucokinase was higher with with beta- than with alpha-D-glucose, whatever the glucose concentration. The appa...

Glycosylation is an immensely important biological process and one that is highly controlled and very efficient in nature. However, in a chemical laboratory the process is much more challenging and usually requires the extensive use of protecting groups to squelch reactivity at undesired reactive moieties. Nonetheless, by taking advantage of the differential reactivity of the anomeric center, a...

Accurate ab initio calculations including basis set limit (BSL) extrapolations, removal of intramolecular basis set superposition error (BSSE), solvent effect corrections, and thermal effects have been carried out to compare the structure and the anomeric and exo-anomeric effect in 2-methoxytetrahydropyran and 2-methoxythiane. The effect of intramolecular BSSE on the energetics was outlined for...

Yeast phosphoglucose isomerase is shown to use and produce both the u and the fi anomeric forms of fructofuranose 6-phosphate. Rapid quench techniques show a Z&fold preference in the utilization of the a! anomer over the /3 anomeric form. The previous report that the (Y anomer of glucopyranose-6-P is the preferred substrate form is confirmed. However the /3 anomer is also shown to react at a sl...

One of the questions not yet elucidated in electrocatalytic oxidation glucose is whether first step dehydrogenating proton-coupled electron transfer (PCET) concerns hydrogen directly bound to an anomeric carbon (β-anomer) or that oxygen (α-anomer). The knowledge necessary for renewable-energy-powered electrosynthesis chemicals/fuels. To decipher that, we have used α-d-, β-d-, and d-glucose mode...

The vanadium-based catalyst, acts as a homogeneous catalyst for the selective oxidation of various kinds of sulfides with 30% aqueous H2O2. Vanadium-based catalyst was successfully used as the oxygen source for the oxidation of sulfides to sulfoxides for the first time. The sulfoxides were obtained in a good way to high yields without any detectable over-oxidation to sulfones under normal condi...