Glycol aldehyde phosphate

The synthesis of pentose-2,4-diphosphate referred to above gave the best yields of a ribose derivative. Thus, the search for an effective synthesis leading to necessary starting materials such as glycol aldehyde phosphate (GAP) was important Krishnamurthy et al. (1999, 2000) reported new synthetic routes to GAP glycol aldehyde is allowed to react with amidotriphosphate (AmTP) in dilute aqueous solution. The triphosphate derivative is formed from trimetaphosphate and NH4OH. 

What importance could vinylphosphonic acid have for the synthesis of important biomolecules Its photolysis gives many oxidized products, including phosphoac-etaldehyde. This analogue of glycol aldehyde phosphate seems to be of interest its formation involves the recombination of hydroxyl radicals with vinylphosphonic acid radicals. 

Transfer of glycolic aldehyde from xylulose 5-phosphate onto ribose 5-phosphate or the first transketolase reaction. The next reaction, which is catalyzed by transketolase, involves the pentose phosphates produced by the foregoing reaction (the transferable moiety is shown in the box) ... 

Transfer of glycolic aldehyde from xylulose 5-phosphate onto erythrose 4-phosphate or the second transketloase reaction. This reaction is related to the first transketolase reaction and is catalyzed by the same enzyme. The only distinction is that erythrose 4-phosphate acts as an acceptor for glycolic aldehyde ... 

Transketolase is one of several enzymes that catalyze reactions of intermediates with a negative charge on what was initially a carbonyl carbon atom. All such enzymes require thiamine pyrophosphate (TPP) as a cofactor (chapter 10). The transketolase reaction is initiated by addition of the thiamine pyrophosphate anion to the carbonyl of a ketose phosphate, for example xylulose-5-phosphate (fig. 12.33). The adduct next undergoes an aldol-like cleavage. Carbons 1 and 2 are retained on the enzyme in the form of the glycol-aldehyde derivative of TPP. This intermediate condenses with the carbonyl of another aldolase. If the reactants are xylulose-5-phosphate and ribose-5-phosphate, the products are glyceraldehyde-3-phosphate and the seven-carbon ketose, sedoheptulose-7-phosphate (see fig. 12.33). 

Butlerov found out that in alkaline medium (calcium hydroxide), formaldehyde HCHO polymerizes to form about 20 different sugars as racemic mixtures, Butlerov 1861. The reaction requires a divalent metal ion. Breslow found a detailed mechanism of reaction that explains the reaction products, (Breslow 1959). He found that glycol-aldehyde is the first product that is subsequently converted into glyceral-dehyde (a triose), di-hydroxy-acetone, and then into various other sugars, tetrose, pentose, and hexose. The formose reaction advances in an autocatalytic way in which the reaction product is itself the catalyst for that reaction with a long induction period. The intermediary steps proceed via aldol and retro-aldol condensations and, in addition, keto-enol tautomerizations. It remains unexplained how the phosphorylation of 3-glyceraldehyde leads to glycral-3-phosphate (Fig. 3.6). Future work should study whether or not ribozymes exist that can carry out this reaction in a stereo-specific way. 

Fig. 15.4 Reaction of transketolase. (a) Typical transketolase reaction. TPP is thiamine pyrophosphate bound in the enzyme. C-2 unit from fructose 6-phosphate (C6) is transferred to aldose phosphate (ribose 5-phosphate in the figure, C5) via TPP to produce shorto ketose (erythulose 4-phosphate, C4) and longer chain length ketose product (sedoheptulose 7-phosphate, C7). (b) Proposed reaction with 5KGA. C2 unit of 5KGA might be transferred to TPP in the enzyme as described in a. The remaining part of 5KGA is tartaric semialdehyde, which is oxidized by a certain enzyme in acetic acid bacteria to become L-tartaric acid. C2 unit attached on TPP might be transferred to aldose phosphate as in a, or released to form glycol aldehyde, which is oxidized to become glycolic acid...

The hydroxyl groups on glycols undergo the usual alcohol chemistry giving a wide variety of possible derivatives. Hydroxyls can be converted to aldehydes, alkyl hahdes, amides, amines, a2ides, carboxyUc acids, ethers, mercaptans, nitrate esters, nitriles, nitrite esters, organic esters, peroxides, phosphate esters, and sulfate esters (6,7). 

Di-poly Aldehydes (and ketones) FFAP QF-I, Porapak-Q, Porapak-QS Apiezon L, M carbowax 400, 750, 1000, 1500, 1540 di-n-butyl phthalate diethylene glycol succinate ethylene glycol succinate Hallcomid M18 squalene tricresyl phosphate 1,2,3-tris (2-cyanoethoxy) propane Ucon series... 

Many systems of this type exist, examples of which are Cr+ or Fe3+--thiourea (tested in polymerizations of acrylonitrile, methyl acrylate and acrylamide [44] Ce3+ with alcohols, aldehydes, amines, phosphates and carboxylic acids [45] V5+ with glycols, Mn3+ with dicarboxylic acid and their derivatives [46] Fe3+ with benzoin [47] etc. 

Other aldehydes and related compounds have been reacted either alone or catalyzed with sulfuric acid, zinc chloride, magnesium chloride, ammonium chloride, or diammonium phosphate (94). Compounds such as l,3-bis(hydroxymethyl)-2-imidazolidone, glycol acetate, acrolein, chloroacetaldehyde, heptaldehyde, o- and p-chloro-benzaldehydes, furfural, p-hydroxybenzaldehyde, and m-nitrobenz-aldehyde all achieve the ASE by a bulking mechanism and not by low-level cross-linking. At weight gains of 15-25%, the highest ASE reported is 40%. 

Intermediate IIA was prepared by the same method as intermediate II except that 0.1 mM octanal was present. Because aldehyde binding to luciferase is reversible and the two would presumably be separated in the column, octanal (50 pM) was also added to the column buffer (50% ethylene glycol phosphate). The activity was eluted in its characteristic position, but in smaller yield than intermediate II in the absence of aldehyde. This was partly due to the presence of a considerable amount of free luciferase. In the fractions eluted at the end, the ratio of flavin to protein increased, indicating that flavin initially bound to luciferase was released during chromatography and retarded somewhat on the column. This suggested that intermediate IIA was broken down on the column as the amount of FMN contaminating luciferase was considerable. It was therefore impossible to isolate pure intermediate IIA by this procedure. 

S)-[l-2H,3H]ethylene glycol, respectively, to racemic acetaldehyde. Racemic acetaldehyde is also formed in the cleavage of 2-deoxyribose 5-phosphate by a specific aldolase (90), and the incubation of stereospecifically labeled dihy-droxyacetone phosphate with methylglyoxal synthetase gives racemic methyl-glyoxal (pyruvic aldehyde) (91). 

TRISODIUM PHOSPHATE (7601-54-9, anhydrous 10101-89-0, dodecahydrate 10361-89-4 7758-29-4 7785-84-4) Na3P04 12H20 Reacts with moisture in air, forming sodium carbonate. Aqueous solution is a strong caustic. Violent reaction with acids. Incompatible with organic anhydrides, acrylates, alcohols, aldehydes, alkylene oxides, substituted allyls, cresols, caprolactam solution, epichlorohydrin, ethylene dichloride, glycols, isocyanates, ketones, maleic anhydride, nitrates, nitromethane, phenols, vinyl acetate. Attacks aluminum, copper, zinc, and related alloys in the presence of moisture. 

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