Fructose 6-phosphate, preparation

D-ifereo-Pentulose (u-xylulose, tentatively identified as the osazone) was found chromatographically to be among the products of the action of a pea enzyme on glycolaldehyde and triose phosphate (prepared from D-fructose 1,6-diphosphate)similarly, 6-deoxy-D-fructose and 6-deoxy-L-sorbosc resulted from DL-lactaldehyde, sedoheptulose from n-erythrose, " 5-deoxy-D-triose phosphate, and D-fdo-heptulosan from n-xylose. ... 

An efficient asymmetric total synthesis of L-fructose combines the Sharpless asymmetric dihydroxylation with an enzyme-catalyzed aldol reaction. L-Glyceraldehyde, prepared from acrolein, is condensed to DHAP in a buffered water suspension of lysed cells of KI2 Escherichia coli containing an excess of L-rhamnulose-1-phosphate (Rha) aldolase E. coli raised on L-rhamnose as sole carbon source). The L-fructose phosphate obtained is hydrolyzed to L-fructose with acid phosphatase. Similarly, the RAMA-catalyzed condensation of D-glyceraldehyde with DHAP,... 

We have developed preparative enzymatic syntheses of several unusual hexoketoses using fructose-1,6-diphosphate aldolase (FDP-aldolase, E.C.4.1.2.13) as catalyst and dihydroxyacetone phosphate (DHAP) and an aldehyde as substrates (15). The enzyme appears to be very specific for DHAP but will accept a variety of aldehydes as acceptors. The ketose-1-phosphates prepared are converted to the phosphate free ketoses after removal of the phosphate group by acid- or phosphatase-catalyzed hydrolysis. The ketoses can be isomerized stereospecifically to aldoses catalyzed by glucose isomerase (E.C.5.3.1.5.) from Flavobacteriuum arborescens. The equilibrium mixtures of aldoses and ketoses are then separated by chromatography on Dowex 50 (Ba ) or Dowex 1 (HSO "). Figure 1 illustrates the preparation of a mixture of 6-deoxy-6-fluoro-D-fructose... 

Sucrose + inorganic phosphate = a-n-glucose 1-phosphate -f- n-fructose Using a-D-glucose 1-phosphate and D-fructose, they prepared sucrose, which was isolated in crystalline form. (See Enzymic synthesis of oligosaccharides, p. 520). 

In continuation of earlier work with over-expressed enzymes from E. coli (see Vol.25, Chapter 7, ref.44), D-tagatose 1,6-diphosphate has been synthesized from dihydroxyacetone by use of a combination of several enzymes including a newly isolated tagatose 1,6-bisphosphate aldolase. An efficient synthesis of D-fructose 1,6-diphosphate by use of four enzymes in a one pot operation has been described. D-[1- C] Fructose 6-phosphate has been prepared from C-enriched formaldehyde and D-ribose 5-phosphate by a formaldehyde fixing enzyme system from Methylomonas aminofaciens, and various C-substituted D-fructose phosphates have been obtained by enzymic methods from C-substituted pyruvate or L-alanine. ... 

The most convenient method is the formation of two equivalents of (25) by retro-aldol cleavage from commercially available (26) by the combined action of FruA and triose phosphate isomerase (Figure 10.18 inset) [84]. This scheme has been extended into a highly integrated, artificial metabolism for the efficacious in situ preparation of (25) from inexpensive feedstock such as glucose and fructose (two equivalents of... 

Figure 10.18 Enzymatic in situ generation of dihydroxyacetone phosphate from fructose 1,6-bisphosphate (b), with extension to an in vitro artificial metabolism for its preparation from inexpensive sugars alongthe glycolysis cascade (a), and utilization for subsequent stereoselective carbon-carbon bond formation using an aldolase with distinct stereoselectivity (c).

Castillo, J.A., Calveras, J., Casas, J. et al. (2006) Fructose-6-phosphate aldolase in organic synthesis preparation of D-fagomine, /V-alkylated derivatives, and preliminary biological assays. Organic Letters, 8, 6067-6070. 

It has recently been reported21 that a mixed osazone of 3,4-di-O-methyl-D-glucose can be converted, by treatment with p-nitrobenzaldehyde, into an osone which reacts with phenylhydrazine to give 3,4-di-O-methyl-D-glucose phenylosazone. Von Lebedev29 claimed to have obtained D-glu-cosone 6-phosphate, isolated as an amorphous lead salt, by the action of hydrochloric acid on the phenylosazone prepared from D-fructose 6-phosphate. 

In this article, the name aldolase is applied to any enzyme preparation that is thought to catalyze an aldol reaction, although it may well be that aldolases differ from one source to another and that many preparations may contain more than one type of aldolase. Thus, the aldolase which splits D-fructose 1-phosphate possibly differs from that which splits D-fructose l,6-diphosphate1M (see Reference 77). 

With zymohexase, fructose 1,6-diphosphate, and acetaldehyde, a 5-de-oxypentulose 1-phosphate resulted,66 and, with a pea-aldolase preparation, the product was identified as 5-deoxy-D-ilireo-pentulose (LXI). Using... 

The direct syntheses of D-glucosyl-L-sorboside from sucrose and L-sorbose and of sucrose from D-glucosyl-D-xyloketoside and D-fructose can be obtained in phosphate-free enzyme preparations.40 The reactions are ... 

Rare or unnatural monosaccharides have many useful applications as nonnutritive sweeteners, glycosidase inhibitors and so on. For example, L-glucose and L-fructose are known to be low-calorie sweeteners. In addition, rare or unnatural monosaccharides are potentially useful as chiral building blocks for the synthesis of biologically active compounds. Therefore, these compounds have been important targets for the development of enzymatic synthesis based in the use of DHAP-dependent aldolases alone or in combination with isomerases. Fessner et al. showed that rare ketose-1-phosphates could be reached not only by aldol addition catalyzed by DHAP-dependent aldolases, but by enzymatic isomerization/ phosphorylation of aldoses [35]. Thus, for example, L-fructose can be prepared... 

Inhibitors of lactic dehydrogenase have been reported in commercial preparations of NAD+ and NADH (B4, M6, S28). The concentration of inhibitory substances varied from lot to lot. In a serum lactic dehydrogenase study with NAD+ from 8 sources, activities were found to vary from 145 to 75 units (B4). Inhibitors of lactic dehydrogenase activity have also been observed in dialyzates in uremic patients (W8) and in human urine (G8). The purity of available substrate can also effect enzyme activity. Schwartz and Bodansky observed that, in 6 batches of fructose 6-phosphate, all weighed to a 0.5 mM concentration, the actual concentration varied from 0.13 mAf to 0.55 mM (S14). 

Schwartz, M. K., and Bodansky, 0., Use of commercially available preparations of fructose-6-phosphate in the determination of phosphohexose isomerase activity. Anal. Biochem. 11, 48-53 (1965). 

The original preparation of 6-C-perfluoroalkyl-D-fructose has been reported. The first step of this synthesis is the perfluoroalkylation of acrolein acetal. The key step of the synthesis is an aldol condensation between D-3-fluoroalkylglyceraldehyde and dihydroxyacetone phosphate, with RAMA as biocatalyst (RAMA is an aldolase found in rabbit muscles) (Figure 6.43). ... 

---