- DNA strand-breaking activity and mutagenicity of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP), a Maillard reaction product of glucose and glycine
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Aqueous solution of glucose and glycine was heated under reflux for 4 h and extracted with ethyl acetate. Reversed phase HPLC of the extract revealed a new DNA strand-breaking substance, which was purified by repeated HPLC and identified as 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP). DDMP induced DNA strand breaking in a dose- and time-dependent manner. It was active to break DNA strands at pH 7.4 and 9.4. Its pyranone skeleton was destroyed at the pH values. DNA strand breaking by DDMP was inhibited by superoxide dismutase, catalase, scavengers for hydroxyl radical, spin trapping agents and metal chelators, and the breaking was enhanced by Fe(III) ion. A mixture of DDMP and a spin trap DMPO gave electron spin resonance signals of a spin adduct DMPO-OH, indicating generation of hydroxyl radical. DDMP was found to be mutagenic to Salmonella typhimurium TA100 without metabolic activation. These results show DDMP generated active oxygen species to cause DNA strand breaking and mutagenesis.
- Hiramoto, Kazuyuki,Nasuhara, Akiko,Michikoshi, Kae,Kato, Tetsuta,Kikugawa, Kiyomi
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- Analysis of furanone, pyranone, and new heterocyclic colored compounds from sugar-glycine model maillard systems
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Aqueous sugar (xylose or glucose)-glycine model systems were refluxed for 2 h with the pH maintained at 5. Reverse-phase HPLC of the total reaction products gave two resolved peaks (one of which was colored) for the xylose system and five resolved peaks (two of which were colored) for the glucose system. The components responsible for these peaks were isolated from the ethyl acetate extracts by semipreparative HPLC. Using mainly NMR, the colored compound from the xylose system was identified as the new 2-acetyl-6- (hydroxymethyl)-5,6-dihydro-4H-pyridinone. The colored compounds from the glucose system were most likely to be two novel cis/trans ring isomers of the related new compound 2-acetyl-6-hydroxy-7-(hydroxymethyl)-1,5,6,7-tetrahydro- 4H-azepinone. These compounds are the first one-ring structures isolated from sugar-amino acid model systems that are reported to be colored. Two of the colorless components of the glucose system were identified, mainly by NMR experiments, as the related compounds 4-hydroxy-2-(hydroxymethyl)-5-methyl- 3(2H)-furanone and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyranone. The remaining compound from the glucose system and the colorless compound from the xylose system were identified as 5-(hydroxymethyl)furfural and 4-hydroxy- 5-methyl-3(2H)-furanone, respectively.
- Ames, Jennifer M.,Bailey, Richard G.,Mann, John
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- Oxygen-dependent fragmentation reactions during the degradation of 1-deoxy-d-erythro-hexo-2,3-diulose
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With this work, we report on further insights into the chemistry of 1-deoxy-d-erythro-hexo-2,3-diulose (1-deoxyglucosone, 1-DG). This α-dicarbonyl plays an important role as a highly reactive intermediate in the Maillard chemistry of hexoses. Degradation of 1-DG in the presence of the amino acid l-alanine led to the formation of several products. Lactic acid and glyceric acid were found to be major degradation products. Their formation was dependent on the presence of oxygen. Therefore, a mechanism is postulated based on oxidation leading to a tricarbonyl intermediate. Carbonyl cleavage of this structure should then give rise to carboxylic acids. This mechanism was supported by the isotope distribution observed during degradation of different 13C-labeled d-glucose isotopomers. Furthermore, we identified 3,5-dihydroxy-6-methyl-2,3-dihydro-4H-pyran-4-one (γ-pyranone) to be capable of rehydration forming 1-DG to a minor extent and therefore leading to the same degradation products. The formation of carboxylic acids from γ-pyranone was also dependent on the presence of oxygen in agreement with the postulated oxidative fragmentation. Finally, we investigated the formation of aldehydes expected as retro-aldol products formed within the degradation of 1-DG. Results seemed to rule out this reaction as an important degradation pathway under the conditions investigated herein.
- Voigt, Michael,Smuda, Mareen,Pfahler, Christoph,Glomb, Marcus A.
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experimental part
p. 5685 - 5691
(2011/08/05)
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- Reactivity of 1-deoxy-D-erythro-hexo-2,3-diulose; A key intermediate in the maillard chemistry of hexoses
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Degradation of 1-deoxyhexo-2,3-diulose, a key intermediate in Maillard chemistry, in the presence of L-alanine under moderate conditions (37 and 50 °C) was investigated. Different analytical strategies were accomplished to cover the broad range of product
- Voigt, Michael,Glomb, Marcus A.
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experimental part
p. 4765 - 4770
(2010/06/14)
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- SYNTHESIS OF A DERIVATIVE OF 1-DEOXY-D-erythro-2,3-HEXODIULOSE AND ITS CONVERSION INTO NONENZYMIC BROWNING PRODUCTS
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A new synthesis of 1-deoxy-4,5-O-isopropylidene-D-erythro-2,3-hexodiulose (5), a stable derivative of the elusive 1-deoxy-D-erythro-2,3-hexodiulose (6), starting from 3,6-anhydro-4,5-O-isopropylidene-D-mannitol (1) is described.Acid hydrolysis of 5 produced 6, which without isolation was treated with piperidine acetate to yield piperidino-hexose-reductone (7) and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (8).A third component in the reaction mixture has been tentatively assigned from mass-spectroscopic data the structure 4-hydroxy-2-hydroxymethyl-5-methyl-3(2H)-furanone (9).
- Fisher, Benjamin E.,Sinclair, Henry B.,Goodwin, James C.
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p. 209 - 216
(2007/10/02)
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