Arginine glyoxals

Table 4.16. Concentrations of pentosidine in foods guanidino group of arginine. The recently identified compound Bisarg (Formula 4.100) is a condensation product of 2 molecules each of arginine, glyoxal and furfural. Apart from the protein cross-linking properties, the intensive brown-orange color of Bisarg should be mentioned.

Figure 12.10 The imidazole reaction between glyoxal and arginine creates cyclic addition compounds lacking positive charge.

Cotham WE, Metz TO, Ferguson PL, et al. Proteomic analysis of arginine adducts on glyoxal-modified ribonuclease. Mol. Cell. Proteomics 2004 3 1145-1153. 

The reaction of dicarbonyl compounds, such as glyoxal or phenylglyoxal, with a guanidinyl group, such as that of an arginine residue, proceeds to yield a more stable linkage due to the formation of a cyclic derivative (Reaction 46). 

The ability to direct conjugation or modification specifically through arginine residues using this chemistry has been exploited in the availability of the only photoreactive glyoxal derivative, APG. 

APG, p-azidophcnyl glyoxal, is a heterobifunctional crosslinker containing an arginine-specific diketone group on one end and a photosensitive phenyl azide group on the other end (Thermo... 

Much attention has recently been paid to arginine as a melanoidin precursor. In a model system, lV -acetylarginine was first allowed to react with glyoxal in aqueous solution at pH 7, followed by furfural. Repeated chromatography of the aqueous residue after ethyl acetate extraction led to a 1% yield of the deep red 29.180 Such a compound provides an example of a potentially coloured crosslink in proteins derived by the Maillard reaction (see Chapter 8). 

M. A. Glomb and G. Lang, Isolation and characterization of glyoxal-arginine modifications, J. Agric. Food Chem., 2001, 49, 1493-1501. 

T. Hofmann, 4-Alkylidene-2-imino-5-[4-alkylidene-5-oxo-l,3-imidazol-2-inyl]aza-methylidine-l,3-imidazolidine —A novel colored substructure in melanoidins formed by Maillard reactions of bound arginine with glyoxal and furan-2-carboxaldehyde, J. Agric. Food Chem., 1998, 46, 3896-3901. 

U. Schwarzenbolz, T. Henle, and H. Klostermeyer, Studies on the reaction of glyoxal with protein-bound arginine, in F, 1998, 443. 

M. O. Lederer and R. G. Klaiber, Cross-linking of proteins by Maillard processes Characterization and detection of lysine-arginine cross-links derived from glyoxal and methylglyoxal, Bioorg. Med. Chem., 1999, 7, 2499-2507. 

Imidazolone adducts formed by reaction of 3-deoxyglucosone or methylglyoxal with arginine and the imidazolium cross-links formed by the reaction of glyoxal and methylglyoxal with lysine residues in protein are also considered as biomarkers of protein oxidative damage (08). 

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