Glycolaldehyde phosphate

As already shown in Sect. 4.4, ribose-2,4-diphosphate is obtained in a base-catalysed condensation of glycolaldehyde phosphate in the presence of formaldehyde (Muller et al., 1990). The phosphate group in the 4 position of the sugar prevents the formation of a 5-membered furanose ring, but a 6-membered pyranose structure can be formed. 

FIGURE 5.2 Synthesis of ribose-2,4-diphosphate from glycolaldehyde phosphate, as proposed by Eschenmoser. 

Aldomerisierung von glycolaldehyd-phosphat zu racemischen hexose-2,4,6-triphosphaten und (in Gegenwart von Formaldehyd) racemischen pentose-2,4-diphosphaten rac-allose-2,4,6-triphos- 82. 

SCHEME 13.2 Selective condensations of glycolaldehyde phosphate alone (a) or in the presence of formaldehyde (b). 

Muller, D, Pitsch, S, Kittaka, A, Wagner, E, Wintner, C E, Eschenmoser, A, Chemie von a-Aminonitrilen. Aldomerisierung von Glycolaldehyd-phosphat zu racemischen Hexose-2,4,6-triphosphaten und (in Gegenwart von Eormaldehyd) racemischen Pentose-2,4-diphosphaten rac-Allose-2,4,6-triphosphat und rac-Ribose-2,4-diphosphat sind die Reaktionhauptprodukte, Helv. Chim. Acta, 73, 1410-1468, 1990. 

Eschenmoser and co-workers [35] studied the aldomerization of glycoaldehyde phosphate which led to mixtures containing mostly racemates of the two diastereomeric tetrose 2,4-di-phosphate and eight hexose 2,4,6-triphosphates (O Scheme 2, route A). At 20 °C in the absence of air, a 0.08-molar solution of glycolaldehyde phosphate 2 in 2-M NaOH gave 80% yield of a 1 10 mixture of tetrose 3 and hexose 4 derivatives with DL-allose 2,4,6-triphosphate comprising up to 50% of the mixture of sugar phosphate [36]. 

A) Selective condensation of glycolaldehyde phosphate alon (B) in the presence of fomialdehyde... 

Reaction catalysed by 2-C-methyl-D-erythritol-4-phosphate synthetase. The reaction is drawn with a metal-templated reverse aldol-aldol mechanism, rather than the alkyl shift mechanism. The prop-2-en-2,3-diolate is below the plane of the glycolaldehyde phosphate. 

Eschenmoser et al. have also postulated that the Btlrgi-Dunitz trajectory must be taken into account in discussions of the kinetic preference for formation of allose 2,4,6-triphosphate in the hexose series and of ribose 2,4-diphosphate in the pentose series, by aldomerization of glycolaldehyde phosphate in aqueous NaOH solution [37]. In this analysis, however, an additional interaction between the donor and acceptor substituents (b <-> f in Figure 6.40) is supposed to increase when the approach is non-perpendicular. 

Fig. 6.40. Eschenmoser s interpretation of glycolaldehyde phosphate aldomerisation reactions [37] It is generally appreciated... that the BUrgi-Dunitz trajectory... for nucleophilic addition to C = 0 groups must be taken into account as steric interactions between reaction center substituents are evaluated. The drawings in (this figure) remind the reader why. While it can be difficult to weigh the contributions of the four relevant interactions for an aldehyde/ketone-enolate pair, the problem for the case of an aldehyde/aldehyde-enolate pair turns out to have a unique solution the one indicated in (this figure), where none of the interacting substituents is juxtaposed with a non-H-atom partner ...

E. Wagner, Y. Xiang, K. Baumann, J. Guck, A. Eschenmoser, Chemistry of alpha-aminonitriles — aziridine-2-carbonitrile, a source for racemic 03-phosphoserinenetrile and glycolaldehyde phosphate, Helv. Chim. Acta 73 (1990) 1391-1409. 

S. Pitsch, E. Pombovillar, A. Eschenmoser, Chemistry of alpha-aminonitriles. 13. Pormation of 2-oxoethyl phosphates (glycolaldehyde phosphates) from rac-oxiranecarbonitrile and on (formal) constitutional relationships between 2-oxoethyl phosphates and oligo(hexopyranosyl and pentopyranosyl) nucleotide backbones, Helv. Chim. Acta 77 (1994) 2251-2285. 

V. Klybas, M. Schramm, and E. Racker, Oxidative pentose phosphate cycle. IV. Synthesis of sedoheptulose 1,7-diphosphate, sedoheptulose 7-phosphate, glyceraldehyde 3-phosphate, and glycolaldehyde phosphate, Arch. Biochem. Biophys., 80 (1959) 229-235. 

Arrhenius, Eschenmoser, and colleagues have examined the reactions of the material formed by substitution of the glycolaldehyde phosphate dianion into Mg2A-l(OH)eiCl, in connection with processes possibly related to the origins of life. Incorporation into the LDH promotes self-addition to form four- and six-carbon sugar di- and triphosphates. Of particular interest is the fact that the LDH alters the stereospecificity of the reaction, and that reaction in the presence of formaldehyde leads to pentose-(including ribose)-2,4-disphosphates (279-281). 

A more complex example, triosephosphate dehydrogenase, is strongly inhibited by a tetrose bisphosphate that contaminates preparations of glycolaldehyde phosphate, of which it is a condensation product. The... 

Glycine, 94, 104 Glycolaldehyde phosphate, 20 Glycolic acid, 4 Glyconolactones, 21 Glycosidases, 22 Glyoxal, 64... 

A comprehensive paper has been published on the self condensation of glycolaldehyde phosphate and the condensation of glycolaldehyde phosphate - formaldehyde mixtures in aqueous NaOH. The major products (ca. 50% of the total) were DL-allose 2,4,6-triphosphate and DL-ribose 2,4 phosphate, respectively, indicating that erythro-aldolisation predominates. ... 

The mono- and diphosphates of ribulose have been reported to be present among early products of photosynthetic CO2 fixation in algae, e.g., Scenedeamus. A pathway for the origin of this diphosphate has not yet been suggested, although Marmur and Schlenk have described the aldolase-catalyzed combination of dihydroxyacetone phosphate and glycolaldehyde phosphate to form what must have been a ketopentose diphosphate. ... 

The p3nranose or furanose structure of the esters appears to influence the rate of hydrolysis. Thus glucose 6-phosphate which can form a pyranose ring is more stable than fructose 6-phosphate which can only form a furanose ring. The acid lability of some compounds such as glycolaldehyde phosphate , erythrose 4-phosphate and erythrulose phosphate may be partly due to the fact that they cannot form ring structures. Furthermore ribose 5-phosphate is more stable than ribulose 5-phosphate and in this case the difference is presumably due to the fact that the former can form a furanose ring while the latter can only exist in the linear form. 

Glycolaldehyde phosphate has been prepared by periodate oxidation of some phosphate esters such as a-glycerophosphate ° or ribose 5-phosphate and also by oxidation of the latter by lead tetraacetate . No enzymes acting on glycolaldehyde have been described. 

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