A-D-Glucopyranose 1-phosphate

In this connection it may be mentioned that many ordinary yeasts ferment, generally very slowly, isomaltose and trisaccharides (limit dextrins) with one maltose and one isomaltose linkage. - Dried yeasts ferment starch and limit dextrins mth a fairly high velocity. This fermentation is probably not due to a hydrolysis of the saccharides to D-glucose or maltose, but to a phosphorolysis to the Cori ester (a-D-glucopyranose 1-phosphate). 

It appears that phosphorus is related to the formation of starch in the plant. Thus Hanes has synthesized a linear polysaccharide from a-D-glucopyranose 1-phosphate (Cori ester) through the action of potato phosphorylase. Dunlap and Beckmann and likewise Cori have found that the B-fraction activates this enzymic synthesis, while the A-frac-tion is inactive. It has not been established whether this effect is due to the branched character of the B-fraction or to the presence of phosphate in its structure. 

The boranodiphosphate analogue 212 of ADP-glucose has been synthesized, in a procedure in which a 5 -phosphoramidite of adenosine was treated with a borane-amine complex, and the product then deprotected and coupled with a-D-glucopyranose-1 -phosphate. ... 

Scheme 5 shows the synthesis of 6-sulphono-a-D-glucopyranose 1-phosphate from the appropriately protected a-D-glucose 1-phosphate (13) via the disulphide (14). The product was isolated as the tris-cyclohexylammonium salt (15). A convenient route to 6-thio derivatives of D-glucal from D-glucose is referred to in Chapter 13. 

Procedures for the preparation of a-D-glucopyranose 1-phosphate from potato starch and for the synthesis of 4,6-dideoxy-a- and - -L,-lyxo-hexo pyranose 1-phosphates and 2,6-dideoxy-cx-L-flra6/ o-hexopyranose 1-phosphate have been described. The orthoesters (73) and (74) were stereospecifically... 

It had been known from at least the time of Pasteur that the presence of sodium or potassium phosphate aided the progress of a yeast fermentation. Later intensive study showed that a complex group of enzymes (phosphatases and phosphorylases) was responsible for the phosphorylation, dephosphorylation and interconversion of D-glucose 6-phosphate, D-fructose 6-phosphate, D-fructose 1,6-diphosphate and similar substances in various types of cells and muscle tissue. Detailed reviews of the field are available. - A further advance was made in 1936, when Cori and Cori noted that in certain circumstances well-washed frog muscle immersed in a sodium phosphate buffer utilized the inorganic phosphate to produce a new hexose phosphate (the Cori ester). This compound was later shown to be a-D-glucopyranose-l-phosphate and yielded crystalline dipotassium and brucine salts. The Cori ester arose because... 

Several 1 -phosphates of deoxyfluoro sugars were prepared, and their acid-catalyzed hydrolysis was studied. 2-Deoxy-2-fluoro- (580), 3-deoxy-3-fluoro- (582), 4-deoxy-4-fluoro- (583), and 6-deoxy-6-fluoro-a-D-gluco-pyranosyl phosphates (584) were prepared by treatment of the corresponding per-( -acetylated )9-D-glucopyranoses with phosphoric acid [the p anomer (581) of 580 was prepared by a different method]. The first and second ionization constants (pA a, and pA a2) of these compounds were determined potentiometrically, as well as by the F-n.m.r. chemical shifts at a series of pH values, and then the rate constants of hydrolysis for neutral (B) and monoanion (C) were decided. The first-order rate-constants (k) for 580-584 and a-D-glucopyranosyl phosphate (in Af HCIO4,25 °) were 0.068, 0.175, 0.480, 0.270, 1.12, and 4.10 (all as x lOVs), respectively. The rate... 

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