A Method for the Determination of α-Dicarbonyl Compounds

Bednarski, W.; Jedrychowski, L.; Hammond, Earl G.; Nikolov, Z̆ivko L.

doi:10.3168/jds.s0022-0302(89)79387-5

Cited by 41 publications

(40 citation statements)

References 15 publications

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“…It is noteworthy that such high amounts of MGO as present in Manuka honey (Table 1) have not yet been found for any other food item. Low amounts of enzymatically formed GO and MGO were reported for fermented foods such as milk products as well as beer and wine, with concentrations ranging from 3 to 11 mg/kg [27,28]. Furthermore, MGO is known to form during coffee roasting in amounts of 23 -47 mg/mg [29].…”

Section: Discussionmentioning

confidence: 97%

Identification and quantification of methylglyoxal as the dominant antibacterial constituent of Manuka (Leptospermum scoparium) honeys from New Zealand

Mavric

Wittmann

Barth

et al. 2008

Molecular Nutrition Food Res

574

527

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The 1,2-dicarbonyl compounds 3-deoxyglucosulose (3-DG), glyoxal (GO), and methylglyoxal (MGO) were measured as the corresponding quinoxalines after derivatization with orthophenylendiamine using RP-HPLC and UV-detection in commercially available honey samples. Whereas for most of the samples values for 3-DG, MGO, and GO were comparable to previously published data, for six samples of New Zealand Manuka (Leptospermum scoparium) honey very high amounts of MGO were found, ranging from 38 to 761 mg/kg, which is up to 100-fold higher compared to conventional honeys. MGO was unambigously identified as the corresponding quinoxaline via photodiodearry detection as well as by means of mass spectroscopy. Antibacterial activity of honey and solutions of 1,2-dicarbonyl towards Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were analyzed using an agar well diffusion assay. Minimum concentrations needed for inhibition of bacterial growth (minimum inhibitory concentration, MIC) of MGO were 1.1 mM for both types of bacteria. MIC for GO was 6.9 mM (E. coli) or 4.3 mM (S. aureus), respectively. 3-DG showed no inhibition in concentrations up to 60 mM. Whereas most of the honey samples investigated showed no inhibition in dilutions of 80% (v/v with water) or below, the samples of Manuka honey exhibited antibacterial activity when diluted to 15-30%, which corresponded to MGO concentrations of 1.1-1.8 mM. This clearly demonstrates that the pronounced antibacterial activity of New Zealand Manuka honey directly originates from MGO.

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Section: Discussionmentioning

confidence: 97%

Identification and quantification of methylglyoxal as the dominant antibacterial constituent of Manuka (Leptospermum scoparium) honeys from New Zealand

Mavric

Wittmann

Barth

et al. 2008

Molecular Nutrition Food Res

574

527

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“…It is derived from previous studies using diaminobenzene for the determination of diacetyl and related products. 17,18 MATERIALS AND METHODS Reagents Dicarbonyl compounds were purchased from Aldrich Chemicals and used without further puri®cation: glyoxal (12,, methylglyoxal (17,, phenylglyoxal (14,243-3) diacetyl (B8,530-7), pentane-2,3-dione (24,196-2) and hexane-2,3-dione (14,. 1,2-Diaminobenzene (Sigma, o-phenylenediamine P-9029) was used directly in powder form or as an aqueous solution.…”

Section: Introductionmentioning

confidence: 98%

The detection of ?-dicarbonyl compounds in wine by formation of quinoxaline derivatives

Revel

Pripis-Nicolau

Barbe

et al. 2000

J. Sci. Food Agric.

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“…(L. casei and L. delbrueckii, subsp. bulgaricus) [56,57]. In bacteria, most of the evidence favor the production of MG from DAP via the enzyme MG synthase, encoded in Escherichia coli by the mgsA gene [67].…”

Section: Generalmentioning

confidence: 99%

“…The methods, validated for specific samples, were used for determination of MG in different wines [37,53,54], beer [54], lipids [42,55], dairy products [56,57], honey [58], and many others.…”

Section: Quantification Of Methylglyoxal In Food Samples and Cigarettmentioning

confidence: 99%

Methylglyoxal in food and living organisms

Nemet

Varga-Defterdarović

Turk³

2006

Molecular Nutrition Food Res

145

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Methylglyoxal (MG) is a highly reactive alpha-oxoaldehyde formed endogenously in numerous enzymatic and nonenzymatic reactions. It modifies arginine and lysine residues in proteins forming advanced glycation end-products such as N(delta)-(5-methyl-4-imidazolon-2-yl)-L-ornithine (MG-H1), 2-amino-5-(2-amino-5-hydro-5-methyl-4-imidazolon-1-yl)pentanoic acid (MG-H2), 2-amino-5-(2-amino-4-hydro-4-methyl-5-imidazolon-1-yl)pentanoic acid (MG-H3), argpyrimidine, N(delta)-(4-carboxy-4,6-dimethyl-5,6-dihydroxy-1,4,5,6-tetrahydropyrimidine-2-yl)-L-ornithine (THP), N(epsilon)-(1-carboxyethyl)lysine (CEL), MG-derived lysine dimer (MOLD), and 2-ammonio-6-({2-[4-ammonio-5-oxido-5-oxopently)amino]-4-methyl-4,5-dihydro-1H-imidazol-5-ylidene}amino)hexanoate (MODIC), which have been identified in vivo and are associated with complications of diabetes and some neurodegenerative diseases. In foodstuffs and beverages, MG is formed during processing, cooking, and prolonged storage. Fasting and metabolic disorders and/or defects in MG detoxification processes cause accumulation of this reactive dicarbonyl in vivo. In addition, the intake of low doses of MG over a prolonged period of time can cause degenerative changes in different tissues, and can also exert anticancer activity. MG in biological samples can be quantified by HPLC or GC methods with preliminary derivatization into more stable chromophores and/or fluorophores, or derivatives suitable for determination by MS by use of diamino derivatives of benzene and naphthalene, 6-hydroxy-2,4,5-triaminopyrimidine, cysteamine, and o-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine. The methods include three basic steps: deproteinization, incubation with derivatization agent, and chromatographic analysis with or without preliminary extraction of the formed products.

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A Method for the Determination of α-Dicarbonyl Compounds

Cited by 41 publications

References 15 publications

Identification and quantification of methylglyoxal as the dominant antibacterial constituent of Manuka (Leptospermum scoparium) honeys from New Zealand

Identification and quantification of methylglyoxal as the dominant antibacterial constituent of Manuka (Leptospermum scoparium) honeys from New Zealand

The detection of ?-dicarbonyl compounds in wine by formation of quinoxaline derivatives

Methylglyoxal in food and living organisms

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