Reduction Mechanism of Tetrazolium Salt XTT by a Glucosamine Derivative

Shimamura, Takeshi; Takamori, Atsuko; Ukeda, Hiroyuki; Sawamura, Masayoshi

doi:10.1271/bbb.67.295

Cited by 8 publications

(3 citation statements)

References 13 publications

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“…Supporting this phenomenon is the observed decrease in intensity of m/z 323.1451 during incubation from 0.5 to 3 days with a concomitant increase intensity of m/z at 321.1286 (Figure 5). Shimamura et al 49 also reported the reducing capacity of dihydrofructosazine.…”

Section: ■ Results and Discussionmentioning

confidence: 96%

Studies on the Formation of Maillard and Caramelization Products from Glucosamine Incubated at 37 °C

Hrynets

Ndagijimana

Betti

2015

J. Agric. Food Chem.

102

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This experiment compared the in vitro degradation of glucosamine (GlcN), N-acetylglucosamine, and glucose in the presence of NH3 incubated at 37 °C in phosphate buffer from 0.5 to 12 days. The reactions were monitored with UV-vis absorption and fluorescence emission spectroscopies, and the main products of degradation, quinoxaline derivatives of α-dicarbonyl compounds and condensation products, were determined using UHPLC-UV and Orbitrap mass spectrometry. GlcN produced two major dicarbonyl compounds, glucosone and 3-deoxyglucosone, ranging from 709 to 3245 mg/kg GlcN and from 272 to 4535 mg/kg GlcN, respectively. 3,4-Dideoxyglucosone-3-ene, glyoxal, hydroxypyruvaldehyde, methylglyoxal, and diacetyl were also detected in lower amounts compared to glucosone and 3-deoxyglucosone. Several pyrazine condensation products resulting from the reaction between dicarbonyls and GlcN were also identified. This study determined that GlcN is a significantly unstable molecule producing a high level of degradation products at 37 °C.

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Section: ■ Results and Discussionmentioning

confidence: 96%

Studies on the Formation of Maillard and Caramelization Products from Glucosamine Incubated at 37 °C

Hrynets

Ndagijimana

Betti

2015

J. Agric. Food Chem.

102

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“…The reversed-phase separation was performed on an Ascentis Express ES-C18 column at a flow rate of 0.9 mL/min with an injection volume of 10 μL. Gradient elution was performed according to the modified method of Shimamura et al 23 with a binary system consisting of (A) 0.1% aqueous formic acid and (B) 100% methanol. The gradient program was as follow: 0−5% B (5−15 min), 5−50% B (15−25 min), 50−5% B (25−35 min), and re-equilibration for 10 min.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

Iron (Fe²⁺)-Catalyzed Glucosamine Browning at 50 °C: Identification and Quantification of Major Flavor Compounds for Antibacterial Activity

Hrynets

Bhattacherjee

Ndagijimana

et al. 2016

J. Agric. Food Chem.

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Glucosamine browning at 50 °C with (GlcN/Fe(2+)) or without iron (GlcN) was studied over time from 0 to 48 h. Generation of reactive oxygen species (ROS), H2O2, and (1)O2, along with α-dicarbonyls, fructosazine, and deoxyfructosazine, was evaluated. Singlet oxygen generation increased over time and was greater in GlcN/Fe(2+) caramel solution. The presence of iron significantly increased the concentration of α-dicarbonyls at an early incubation time (3 h). Fructosazine and deoxyfructosazine were the major degradation products at 48 h comprising together up to 37 and 49% in GlcN and GlcN/Fe(2+), respectively. GlcN/Fe(2+) (48 h) exhibited a MIC50 against highly heat-resistant Escherichia coli AW 1.7 at pH 5, but not at pH 7. Despite several antimicrobial compounds being produced during browning, GlcN/Fe(2+) created a synergistic environment for the fructosazine-organic acids to confer their antimicrobial activity. GlcN caramel solutions have the potential to serve as both flavoring compounds and antimicrobial agents in formulated food systems.

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“…Some AGEs, like for instance argpyrimidine, have been recognized to act as reducing agent inducing formation of oxyMb in fructated Mb [ 47 ]. In addition, dihydroxyfructosazines deriving from GlcN cyclocondensation were also reported to carry a reducing power [ 48 ].…”

Section: Resultsmentioning

confidence: 99%

Rapid Myoglobin Aggregation through Glucosamine-Induced α-Dicarbonyl Formation

2015

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The extent of glycation and conformational changes of horse myoglobin (Mb) upon glycation with N-acetyl-glucosamine (GlcNAc), glucose (Glc) and glucosamine (GlcN) were investigated. Among tested sugars, the rate of glycation with GlcN was the most rapid as shown by MALDI and ESI mass spectrometries. Protein oxidation, as evaluated by the amount of carbonyl groups present on Mb, was found to increase exponentially in Mb-Glc conjugates over time, whereas in Mb-GlcN mixtures the carbonyl groups decreased significantly after maximum at 3 days of the reaction. The reaction between GlcN and Mb resulted in a significantly higher amount of α-dicarbonyl compounds, mostly glucosone and 3-deoxyglucosone, ranging from and 27 to 332 mg/L and from 14 to 304 mg/L, respectively. Already at 0.5 days, tertiary structural changes of Mb-GlcN conjugate were observed by altered tryptophan fluorescence. A reduction of metmyoglobin to deoxy-and oxymyoglobin forms was observed on the first day of reaction, coinciding with the greatest amount of glucosone produced. In contrast to native α-helical myoglobin, 41% of the glycated protein sequence was transformed into a β-sheet conformation, as determined by circular dichroism spectropolarimetry. Transmission electron microscopy demonstrated that Mb glycation with GlcN causes the formation of amorphous or fibrous aggregates, started already at 3 reaction days. These aggregates bind to an amyloid-specific dye thioflavin T. With the aid of α-dicarbonyl compounds and advanced products of reaction, this study suggests that the Mb glycation with GlcN induces the unfolding of an initially globular protein structure into amyloid fibrils comprised of a β-sheet structure.

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Reduction Mechanism of Tetrazolium Salt XTT by a Glucosamine Derivative

Cited by 8 publications

References 13 publications

Studies on the Formation of Maillard and Caramelization Products from Glucosamine Incubated at 37 °C

Studies on the Formation of Maillard and Caramelization Products from Glucosamine Incubated at 37 °C

Iron (Fe²⁺)-Catalyzed Glucosamine Browning at 50 °C: Identification and Quantification of Major Flavor Compounds for Antibacterial Activity

Rapid Myoglobin Aggregation through Glucosamine-Induced α-Dicarbonyl Formation

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Reduction Mechanism of Tetrazolium Salt XTT by a Glucosamine Derivative

Cited by 8 publications

References 13 publications

Studies on the Formation of Maillard and Caramelization Products from Glucosamine Incubated at 37 °C

Studies on the Formation of Maillard and Caramelization Products from Glucosamine Incubated at 37 °C

Iron (Fe2+)-Catalyzed Glucosamine Browning at 50 °C: Identification and Quantification of Major Flavor Compounds for Antibacterial Activity

Rapid Myoglobin Aggregation through Glucosamine-Induced α-Dicarbonyl Formation

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Iron (Fe²⁺)-Catalyzed Glucosamine Browning at 50 °C: Identification and Quantification of Major Flavor Compounds for Antibacterial Activity