Use of D-Fructose

D-Fructose is the sweetest natural sugar. Its use as a natural sweetener is, therefore, increasing rapidly. It is absorbed slowly from the intestine, and thus does not cause abrupt changes in the serum levels of carbohydrates. It has little, if any, effect on insulin secretion. Thus, it exerts beneficial effects as a component of diets for mild and well-balanced diabetes, but should be taken within caloric restriction,445 as obesity impairs D-glucose tolerance and increases the insulin resistance of peripheral tissue.446 Use of D-fructose in the direct treatment of diabetic ketoacidosis does not offer advantages over routine, fluid therapy, and may even be dangerous on the basis that rapid infusion of large amounts of D-fructose may cause lactate acidosis. 

Although D-fructose stimulates ethanol metabolism in tissues and perfused liver, the use of D-fructose in the treatment of ethanol intoxication in intact animals still remains controversial.234-239 

Department of Chemistry, Brookhaven National Laboratory, Upton, Long Island, New York 11973 Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706 

The form of this bibliography is similar to that of previous years.1-3 As for that for 1974, projection diagrams of the carbohydrate, nucleoside, or nucleotide molecules or ions have been provided, where possible. The diagrams were produced directly from the unit-cell and atomic positional parameters given in the papers. In a few cases, corrections were necessary. 

For the carbohydrate structures, the CRYSNET facility was used.4 The carbon and hydrogen atoms are shown as small, solid circles, and other atoms by the appropriate symbol. Where positions of hydrogen atoms were not reported, or could not be deduced, the atom is indicated by H. 

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Use of D-fructose by muscle cells is still a matter of debate. The results of in vitro experiments indicate rapid, muscular uptake of D-fructose, with both incorporation into glycogen and oxidation to carbon dioxide. However, when D-glucose is added in increasing amounts to muscle-tissue slices, D-fructose utilization decreases. It follows that metabolism of D-fructose in muscle under normal circumstances is limited, owing to competitive inhibition by D-glucose.73... 

Another name for glucitol obtained by reduction of d glucose is sorbitol it is used as a sweetener especially in special diets required to be low in sugar Reduction of D fructose yields a mixture of glucitol and mannitol corresponding to the two possi ble configurations at the newly generated chirality center at C 2... 

Asymmetric epoxidation of disubstituted E-alkanes using a d-fructose... 

ASYMMETRIC EPOXIDATION OF DISUBSTITUTED E-ALKENES USING A d-FRUCTOSE BASED CATALYST121... 

In a previous work, using D-fructose pyran- and furan- forms as inhibitors of D-fructose transport in CHO (Chinese Hamsters Ovary)-GLUT5 cells, Rollin, Holman and co-workers established that both ring forms were tolerated. The approach used was to block each hydroxyl function with allylic ether it was concluded that two sites, 0-2 (pyranose and furanose) and 0-6 (furanose) could be modified and addressed a visualization of vital interactions with the protein. These interactions were considered to occur because the D-fructofuranose form is relatively symmetrical for that reason, the binding site can arise either in anomeric center side or on the other side of the molecule. Hence D-fructopyranose appears to present to GLUT5 transporter by hydroxyl 3, 4, 5 recognition (Fig. 3). 

With the aim to explore this model of interaction, Rollin and co-workers have developed a method using the OZTs moieties to block the D-fructose structure and analogues. The OZT structures can be regarded as analogues of D-fructose... 

Recently Cavaleiro et al. described an easy synthetic approach to glycoporphyrins from zinc(n) protoporphyrin-IX dimethyl ester 4 and O-allyl carbohydrate acetonides 5A-E (D-ribose (A), D-galactose (B), D-glucose (C), and two isomeric derivatives (D) and (E) of D-fructose) by cross-metathesis (Scheme 2).12 Two equivalents of each carbohydrate and the Grubbs catalyst were used, giving the carbohydrate derivatives 6 in a range of 74% to 93% yields. 

The above-mentioned procedure for the synthesis of C-fructosides has been used to synthesize the bisphosphono analog of / -D-fructose 2,6-bisphos-phate [ 16], which is, as reported in Sect. 2.3, an important activator of glycolysis and inhibitor of gluconeogenesis. To prepare the target molecule we first attempted the conversion of the firee hy iroxyl group of 21 into an iodide which in turn can be easily converted into a phosphonate. However, this conversion... 

Based on the stereospecific transketolase-catalyzed ketol transfer from hydroxy-pyruvate (20) to D-glyceraldehyde 3-phosphate (18), we have thus developed a practical and efficient one-pot procedure for the preparation of the valuable keto-sugar 19 on a gram scale in 82% overall yield [29]. Retro-aldolization of D-fructose 1,6-bisphosphate (2) in the presence of FruA with enzymatic equilibration of the C3 fragments is used as a convenient in-situ source of the triose phosphate 18 (Scheme 2.2.5.8). Spontaneous release of CO2 from the ketol donor 20 renders the overall synthetic reaction irreversible [29]. 

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