Colorimetric Determination of Glucosamine and Glucose Based on the Formation of Blue Molybdosilicate Anion and Its Application to the Assay of Saccharifying Enzyme

Katano, Hajime; Taira, Shu; Uematsu, Kohei; Kimoto, Hisashi

doi:10.2116/analsci.29.1021

Cited by 8 publications

(8 citation statements)

References 20 publications

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“…In the present microtiter plate assay, the color reaction during the mixing operation and the spectrophotometric measurement was negligible, because of much slow reaction rate at room temperature. 7) Also, the Si(IV)-Mo(VI) solution is well buffered with 0.95 M HCl. These may be reasons of the high reproducibility.…”

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confidence: 99%

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Colorimetric determination of fructose for the high-throughput microtiter plate assay of glucose isomerase

Katano

Takakuwa

Itoh

et al. 2015

Bioscience, Biotechnology, and Biochemistry

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A colorimetric method for the reducing monosaccharide determination is optimized for the assay of glucose isomerase, which converts glucose (Glc) to fructose (Fru). Test solution was mixed with 20-fold volume of the 50 mM Na2SiO3, 600 mM Na2MoO4, and 0.95 M HCl aqueous solution (pH 4.5), in which a yellow molybdosilicate species was formed. The mixture was kept at 70 °C for 30 min. Test solution containing 10 mM level Fru gave a remarkable blue reaction mixture, in which the Mo(VI) species was reduced by Fru to form a blue molybdosilicate species. The blueness increased with the Fru concentration. Glc cannot render the reaction mixture blue as strong as Fru. Thus, the colorimetric method can be used advantageously for the determination of 10 mM level Fru in the Glc isomerase reaction mixture, even in the presence of 100 mM level Glc, and has been applied successfully to the microtiter plate assay of the enzyme.

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confidence: 99%

“…In a previous study, 7) we have presented a colorimetric method for the determination of reducing monosaccharide. The method is based on the reduction of Mo(VI) species directly by the saccharide to form blue molybdosilicate species in a Si(IV)-Mo(VI) organic watermixed solution, which was initially yellowish due to the formation of yellow molybdosilicate.…”

mentioning

confidence: 99%

Colorimetric determination of fructose for the high-throughput microtiter plate assay of glucose isomerase

Katano

Takakuwa

Itoh

et al. 2015

Bioscience, Biotechnology, and Biochemistry

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“…In a previous study, 1 we developed a method for reducing monosaccharide assay based on the color reaction in a Si(VI)-Mo(VI) system. The Si(IV)-Mo(VI) solution is initially yellowish due to the formation of yellow molybdosilicate anionic species, 2 and the monosaccharide reduces directly the Mo(VI) species to form a mixed-valence molybdosilicate anion, which renders the solution blue.…”

Section: Introductionmentioning

confidence: 99%

“…8 Since di-, oligo-, and polysaccharides would not interfere with a determination of the monosaccharide at the same concentration level, the method was successfully applied to a microtiter plate assay of saccharifying enzymes. 1,9 The sensitivity of the colorimetric assay differs among monosaccharides. 1,7,9 Especially, glucosamine (GlcN) can be detected with very high sensitivity.…”

Section: Introductionmentioning

confidence: 99%

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Determination of Chitin Based on the Colorimetric Assay of Glucosamine in Acidic Hydrolysate

et al. 2016

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A colorimetric method for the glucosamine (GlcN) assay was applied for the determination of chitin, which can be hydrolyzed to produce GlcN. A 10-mg sample was mixed with 10 mL of a 5 mol/L HCl aqueous solution, and the mixture was kept at 100 C for 12 h. Under these conditions, chitin was completely depolymerized and deacetylated to produce GlcN, even when the sample was a crab shell. A 20-μL aliquot of the hydrolysate was mixed with 20 μL of a 5 mol/L NaOH aqueous solution and 200 μL of a 50 mmol/L Na2SiO3, 600 mmol/L Na2MoO4, 1.5 mol/L CH3COOH and 30% (v/v) dimethyl sulfoxide solution. The mixture was kept at 70 C for 30 min. In the mixture, GlcN reduced the Mo(VI) species to form a blue molybdosilicate anion, which gave an absorbance maximum at around 750 nm. Since N-acetylglucosamine and chitin oligosaccharides could not render the reaction mixture blue, GlcN in the hydrolysate could be assayed colorimetrically with high selectivity. When a standard chitin sample was examined, the GlcN concentration in the hydrolysate was determined to be 0.97 ± 0.02 g/L (as hydrochloride salt), indicating that the sample contained 10.0 ± 0.2 mg chitin (as an N-acetylglucosamine homopolymer). Calcium cation, amino acids, and proteins did not interfere with the GlcN assay. Thus, the proposed method was successfully applied to determine chitin in a crab shell sample.

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Chitin quantitation (as glucosamine) in food raw materials by spectrophotometry

Šulc

2024

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Colorimetric Determination of Glucosamine and Glucose Based on the Formation of Blue Molybdosilicate Anion and Its Application to the Assay of Saccharifying Enzyme

Cited by 8 publications

References 20 publications

Colorimetric determination of fructose for the high-throughput microtiter plate assay of glucose isomerase

Colorimetric determination of fructose for the high-throughput microtiter plate assay of glucose isomerase

Determination of Chitin Based on the Colorimetric Assay of Glucosamine in Acidic Hydrolysate

Chitin quantitation (as glucosamine) in food raw materials by spectrophotometry

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