Interference of Pentose in the Estimation of Hexose Sugars with Anthrone

Johanson, R.

doi:10.1038/171176a0

Cited by 37 publications

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“…It seems probable that the large unfermentable residue detected by the anthrone reagent represents stable glucosides such as flavone pigments which are not removed by yeast. This residue gave the characteristic hexose colour with anthrone, and there was no evidence that pentoses interfered with the analyses(Johanson, 1953)-Although this unfermentable carbohydrate constitutes a substantial part of the total soluble carbohydrate of the tissues, it is a fairly constant fraction, as shown inTable i. In other, similar, experiments no evidence of appreciable diurnal changes of stable glucosides has been found.…”

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confidence: 52%

STOMATAL MOVEMENTS AND CHANGES OF CARBOHYDRATE IN LEAVES OF CHRYSANTHEMUM MAXIMUM

Yemm

Willis

1954

New Phytologist

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confidence: 52%

STOMATAL MOVEMENTS AND CHANGES OF CARBOHYDRATE IN LEAVES OF CHRYSANTHEMUM MAXIMUM

Yemm

Willis

1954

New Phytologist

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“…H 2 SO 4 to give bluishgreen condensation products with absorption maxima at 520-625 nm [2]. The CM was used to develop several quantitative methods for determining monosaccharides [3,4]. A drawback of these is the magnitude of the relative uncertainty and technical difficulties in working with concentrated mineral acids.…”

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confidence: 99%

Absorption spectra of carbohydrates and related compounds in H2SO4

Оленников

Танхаева

2006

Chem Nat Compd

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582.962+581.192 The possibility of modifying the Dreywood anthrone method for spectrophotometric determination of carbohydrates in order to increase the accuracy and reproducibility of the results was examined. The classical method and a developed modification were compared. The relative uncertainty in a determination by the modified method was less than 4%.Sulfuric acid is widely used to analyze organic compounds. It gives colored products with carbohydrates in the presence of several phenols, in particular, a solution of anthrone in H 2 SO 4 gives stable colored compounds [1]. In the classical method (CM), hydroxymethylfurfurol formed upon dehydration of monosaccharides reacts with anthrone in conc. H 2 SO 4 to give bluishgreen condensation products with absorption maxima at 520-625 nm [2]. The CM was used to develop several quantitative methods for determining monosaccharides [3,4]. A drawback of these is the magnitude of the relative uncertainty and technical difficulties in working with concentrated mineral acids. Table 1 gives results from a metrological analysis of the CM using certain monosaccharides as examples. The large uncertainty is probably due to the viscosity of conc. H 2 SO 4 , which causes the colored products to be unevenly distributed in the sample volume.We examined the possibility of thinning the samples with less viscous and more available solvents such as ethanol and water for phytochemical analysis in order to eliminate these drawbacks. Use of the latter is excluded because of the poor solubility of anthrone in aqueous H 2 SO 4 solutions at concentrations less than 70%. Therefore, we used ethanol. The sample was diluted with 95% ethanol after the colored complex was formed.The studied compounds were representatives of the pentose and hexose series, oligosaccharides, and polymeric compounds. The viscosities of the resulting solutions were satisfactory and facilitated even mixing of the reaction mixture. However, yellow solutions formed instead of the expected bluish-green ones. A check of the effect of temperature on the color of the formed complex showed that it affected only the intensity of the color of the final solution. Carrying out the reaction at 20-100°C gave identical results. After dilution with ethanol, yellow solutions were obtained.Absorption spectra of the reaction products exhibited a characteristic band at 405-411 nm. Unreacted anthrone in the mixtures caused absorptions in the range 320-400 nm. This could be avoided by using an anthrone solution as a control. This improved the shape of the spectra and shifted the maxima to 428-431 nm (Fig. 1). The characteristic absorption spectrum was the same for all studied compounds except for galacturonic acid, the principal peak of which was located at 424 nm. The optica l density was linear for 0.2-0.7 relative units for solutions with concentrations 5-35 µg/mL (Fig. 2). The exception was arabinose, for which the range was 25-120 µg/mL.The time required to form the colored complex at 100°C was 10 min. Adding a cooling step afte...

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“…Nucleic acids were estimated directly in intine preparations by the spectrophotometric method of Warburg and Christian (25). The total carbohydrate was measured with anthrone reagent (7) after hydrolysis of insoluble materials in 4 N HCI for 4 hr at 95 C; glucose was used as a standard.…”

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confidence: 99%

Chemical Composition of Azotobacter vinelandii Cysts

Lin

Sadoff

1969

J Bacteriol

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Cysts of Azotobacter vinelandii ATCC 12837 were germinated by exposure to 3.0 mM ethylenediaminetetraacetic acid (EDTA)-tris(hydroxymethyl)aminomethane buffer at pH 7.8, and their outer coats (exines) were purified by differential and isopycnic centrifugation. Electron micrographs of exine showed it to consist of multilayers of a three-membered sheet structure whose thickness was 7.0 to 7.5 nm. The inner, less electron-dense layer (intine) was also prepared from cysts by EDTA treatment, centrifugation, concentration, and dialysis. The exine consisted of 32% carbohydrate, 28% protein, 30% lipid, and 3.2% ash, with the ash comprised of 1.62% calcium, 0.02% magnesium, and 0.34% phosphorus. The amino acid composition of exine was similar to that of gram-negative bacterial cell walls. The intine consisted of 44% carbohydrate, 9.1% protein, 37% lipid, and 4.1% ash, with the ash comprised of 2.45% calcium, 0.02% magnesium, and 0.38% phosphorus. The carbohydrates of both exine and intine contained glucose, mannose, xylose, and rhamnose. Glucosamine and galactosamine were found only in the exines. The fatty acids consisted of normal, iso, and anteiso saturated fatty acids with 10 to 18 carbon atoms and mono-unsaturated C1l, C1,s, and C18 fatty acids. The exines contained mostly bound lipid, but intines contained primarily free lipid.Cells of Azotobacter vinelandii undergo a morphogenetic process which leads to the pro-486

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Interference of Pentose in the Estimation of Hexose Sugars with Anthrone

Cited by 37 publications

References 2 publications

STOMATAL MOVEMENTS AND CHANGES OF CARBOHYDRATE IN LEAVES OF CHRYSANTHEMUM MAXIMUM

STOMATAL MOVEMENTS AND CHANGES OF CARBOHYDRATE IN LEAVES OF CHRYSANTHEMUM MAXIMUM

Absorption spectra of carbohydrates and related compounds in H2SO4

Chemical Composition of Azotobacter vinelandii Cysts

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