Heptuloses Sedoheptulose

D-afe-o-Heptulose (sedoheptulose) (XXXVII) has been synthesized from D-erythrose (XXXVIII) plus triose phosphate, using an aldolase preparation from peas.169 Aldolases from yeast and from rat liver also form heptu-lose phosphate from these substrates.7S(o) 170(a) Crystalline muscle aldolase causes the formation of L-jrZwco-heptulose (XXXVIIa) from a mixture of L-erythrose (XXXVTIIa) and hexose diphosphate.170(b)... 

On the other hand, if the a-pyranose form has substantial unfavorable interactions, the / -pyranose being essentially unstable, the furanoses will become the major components of the equilibrium mixture (see Table V). Thus, over 75% of all molecules of D-alfro-heptulose (sedoheptulose) andD-ido-2-heptulose in solution are in a furanose form at equilibrium at 22° even more is present at higher temperatures. 

Until recent years, the only reducing sugars of the 7-carbon series to have been found in Nature were two ketoheptoses these were o-manno-heptulose and D-aifro-heptulose (sedoheptulose), both of which were isolated from plants, Heptulose phosphates have now been recorded from several sources, for example, from yeast, from early products of photo-... 

Richtmyer, N. K. D-a/fro-Heptulose (Sedoheptulose). Methods in Carbohydrate Chemistry I, 167. New York and London Academic Press. 

LaForge and Hudson194 prepared an osone from the phenylosazone obtained from sedoheptulose (D-aZ(ro-heptulose). The osone reduced Fehling solution strongly, formed the original osazone with phenylhydrazine, and gave a crystalline derivative with o-phenylenediamine. 

Sedoheptulose. See Heptulose, o-altro-. Serine, L-, 266 Shikimic acid, 236-238, 259 biosynthesis of, from o-glucose, 239, 243... 

Heptuloses were believed to be concerned in the biosynthesis of shikimic acid, an intermediate in the biosynthesis of aromatic com-poundsd However, despite the excellent utilization of sedoheptulose... 

The natural occurrence of a heptulose together with a related heptitol would appear to be a general feature, since sedoheptulose is accompanied by (a) volemitol in the root stock of Primula elatior (L) Hill, and (b) j3 -sedoheptitol (D-glycero-jj-gluco-heptitol) in the leaves and stems of... 

T. Okuda and K. Mori, Distribution of mamto-heptulose and sedoheptulose in plants, Phytochemistry, 13 (1974) 961-964. 

D-Sedoheptulose, D-altro-2-heptulose a monosaccharide from Sedum (stonecrop), Af, 210.19, m.p. (monohydrate) 102 °C. The 7-phosphate is an intermediate of carbohydrate metabolism (see, e.g. Pentose phosphate cycle) aldolase reactions of sedoheptu-lose 7-phosphate give rise to D-erythrose 4-phosphate, which is a precursor in Aromatic biosynthesis (see). 

Synonyms. D-aZ ro-Heptulose. Volemulose ( 7 ), obtained by the oxidation of natural volemitol >-glycero-i)4alo-he i to ) with Acetobacter xylinum, has been identified as sedoheptulose (118), possibly contaminated with D-ma/iwo-heptulose (119). Volemose, obtained by hypobromite oxidation of volemitol, is a complex mixture containing mainly the predictable aldoheptoses the name should be abandoned (120). 

The action of an enzyme, transketolase, from rat liver or from spinach, on pentose 5-phosphate results in the formation of a triose phosphate and an ester of sedoheptulose, which is presumably sedoheptulose 7-phosphate. The heptulose has been identified by the preparation of sedoheptulosan tetrabenzoate (227). 

XVI) obtained by reduction of natural sedoheptulose (D-aZoptically inactive hence, incorrect configurations were assigned to it and to the 2-epimer, a-sedoheptitol, the natural volemitol (XV). More recently it has been shown that (XVI) possesses a slight optical activity in water and a somewhat greater activity in borax (7d). 

Methods for degrading ribulose (n-er / Aro-pentulose) and sedoheptulose (n-aZ ro-heptulose) have been devised by Bassham and associates 46). Biological methods of degradation depending on the action of bacteria to produce small fragments such as ethanol, acetic acid, formic acid, lactic acid, etc., are of rather wide use in the sugar field. 

Sedoheptulose (o-a/tro-heptulose) is a natural ketose that plays an important role in metabolism. Its content in natural sources, however, rarely exceeds 1 % [59] so that its synthesis rather than its isolation is preferred. Until now, biochemical and biotechnological methods have been exploited to perform the synthesis [60]. 

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