Xylose paper chromatography

The enzyme catalyzing the transfer of D-apiose from UDP-apiose to 4, 5-dihydroxyflavon-7-yl /3-D-glucopyranoside is commonly called apiin synthetase.7 Activity is measured by the formation of [14C]apiin from UDP-[U-14C]apiose. Apiin synthetase can be measured by the rapid separation and isolation, by poly(ethylenimine)-paper chromatography, of a product of the reaction, namely, [14C] apiin, from UDP-D-[U-14C]xylose and degradation products of UDP-[U-14C]apiose.31 There are reports of the isolation and purification of apiin synthetase from parsley leaves,31 from cell-suspension cultures of parsley,121 and from foxglove (Digitalis purpurea).31 Apiin synthetase isolated from parsley does not require metal ions, NAD+, or other cofactors, and is soluble. It is inhibited by several heavy metals, but not by tetra-N-... 

A fraction of the sirupy diketal was obtained in crystalline form (m. p. 55-56°). This material consumed one mole of periodate (or lead tetraacetate), with the liberation of 0.86 mole of formaldehyde, which fact eliminated all but the 1,2,3,4- and 3,4,5,6-isomers.144 Hydrolysis of the diisopropylidene-ofde/ij/do-pentose formed during the oxidation yielded D-arabinose and so the diisopropylidene-D-sorbitol must have been one of the three members of the latter group. That it was in fact the 3,4 5,6-compound was demonstrated by its partial hydrolysis to 3,4-isopropyli-dene-D-sorbitol.144 Consequently the triketal from which both had been derived must have been l,2 3,4 5,6-triisopropylidene-D-sorbitol. This being so, the sirupy diketal mentioned above should have contained some of the 1,2 3,4- compound, a hypothesis which found support in the observation that periodate oxidation of the sirup and subsequent hydrolysis of the products afforded a mixture of D-arabinose and L-xylose (identified by filter paper chromatography).144... 

The use of quantitative, paper chromatography is discussed in this Section, since one of the most important factors in its application to wood-cellulose analysis is that it permits a satisfactory determination of mannan. Reasonably reliable methods for the determination of xylan have been available for some time, but mannan determinations, for the reasons discussed above, have been less satisfactory. The fact that (on chromatograms) xylose, as well as other carbohydrates, can be determined simultaneously with mannose is an added attraction in the use of this technique. 

Only trace amounts of monosaccharides have so far been detected in soils. The reducing sugars in cold-water extracts of Norwegian soils amounted to less than 1% of the total soil organic matter (2% for peats). Glucose, galactose, xylose, and rhamnose have been identified by paper chromatography in sodium hydroxide extracts of various Scottish soils. 

Puerarin n-xyloside forms an octaacetate, C26H2oOi3(OCCH3)g, m. p. 162-170 , and gives puerarin and n-xylose (identified by paper chromatography) on hydrolysis with methanolic sulfuric acid. 

Glucose Is the major monomer in the 72% H.SO. soluble polysaccharide and comprises about 80 to 85% or the total monomers accounted for (Table VI). Only a trace of arablnose was detected in some peel samples but xylose was found to be In measurable quantities. Several peaks on the chromatograms were found in the various components. They were not Identified positively. Peaks with retention time similar to some anomers of mannose not masked by glucose were found. Mannose has been previously noted by paper chromatography from citrus peel ( ). 

After proteolytic digestion of the xylose-labeled trichloracetic acid precipitate, a labeled compound was isolated which comigrated with autlientie 0- 8-D-xyIosyl-L-serine in electrophoresis and in paper chromatography in several solvent systems. Furthermore, the labeled substance... 

The most promising of currently available methods for the rapid, routine determination of xylose is quantitative, partition chromatography on filter paper, which permits simultaneous determination of mannose and other sugars (see p. 292). 

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