Arabinose chromatography

Arabinose Chromatography Chlorofomi/acetone, pyridine. Araban acetate, charcoal 1107... 

Galactosamine with Ninhydrin to Arabinose and Lyxose and their Identification with Paper Chromatography. Acta chem. scand. 4, 970 (1950). 

Some workers have performed hydrolyses in an autoclave, but it has been shown that 0.5 M sulfuric acid at 120° degrades 33% of L-arabinose and 22% of D-galactose in two hours.75 Such methods are, therefore, only suitable for qualitative analyses, unless accurate corrections are made. Similarly, 90% formic acid has been found76 to decompose 48% of D-xylose and 36% of D-galactose in 20 hours at 100°. Gas-liquid chromatography has been used to examine the products formed by the acid degradation of sugars.77... 

With the aid of column chromatography, Mowery4 studied the rate of formation of furanosides and pyranosides from n-arabinose. The rate of furanoside formation was extrapolated back to zero time, and an initial rate was obtained (see Table III). The less stable anomer, the /3-furanoside, was initially formed to the greater extent in the final equilibrium mixture, the more stable a-n anomer was preponderant. 

The third enzyme in the pathway, KD0-8-phosphate phosphatase, has been purified to homogeneity (26). Because of its abosolute specificity, it should be a focal point for chemotherapeutic studies. jThe apparent for KD0-8-phosp te was+ etermined to be 5.8 x 10 M in the presence of 1.0 mM Co or Mg. This specific KD0-8-phosphate phosphatase was separated from enzymes, present in crude extracts, having phosphatase activity on other phosphorylated compounds by column chromatography on DGAE-Sephadex (26). Three distinct peaks of activity were detected. Fractions from each peak were pooled and the rates for the hydrolysis of five compounds were measured. Peak A possessed phosphatase activity for D-glucose-6-phosphate, D-arabinose-5-phosphate, D-ribose-5-phosphate and j-nitrophenylphosphate Peak B dephosphorylated D-arabinose-5-phosphate, D-ribose-5-phosphate and D-glucose-6-phos-phate. Peak C, which was well separated from the other two peaks, could only utilize KD0-8-phosphate as a substrate. KD0-8-phos-phate was not hydrolyzed by the phosphatases present in peaks A and B. 

A more-direct method of preparation is oxidation of aldoses, and optimal yields are afforded by the action of cupric acetate in methanol or ethanol.417 This method is suitable for large-scale preparation of intermediates however, a pure product is obtained only by chromatographic separation from the unreacted sugar byproducts. The synthesis of D-eryt/wo-pentos-2-ulose and its D-threo isomer by oxidation of D-arabinose and D-xylose, respectively, with cupric acetate followed by anion-exchange chromatography has been reported.418 The only product obtained by oxidation of D-glucose with sodium 2-anthraquinonesulfonate in alkaline... 

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