title: Pyridinium-carbaldehyde: active Maillard reaction product from the reaction of hexoses with lysine residues.
abstract: Besides the formation of the aminotriazine N6-[4-(3-amino-1,2,4-triazin-5-yl)-2,3-dihydroxybutyl]-L-lysine, the reaction of [1-13C]D-glucose with lysine and aminoguanidine leads to the generation of 6-[2-([[amino(imino)methyl]hydrazono]methyl)pyridinium-1-yl]-L-norleucine (14-13C1). The dideoxyosone N6-(2,3-dihydroxy-5,6-dioxohexyl)-L-lysine was shown to be a precursor in the formation of 14-13C1, which proceeds via the reactive carbonyl intermediate 6-(2-formylpyridinium-1-yl)-L-norleucine (13-13C1). In order to study the reactivity of 13-13C1, the model compound 1-butyl-2-formylpyridinium (18) was prepared in a two-step procedure starting from 2-pyridinemethanol. The reaction of the pyridinium-carbaldehyde 18 with L-lysine yielded the Strecker analogous degradation product 2-(aminomethyl)-1-butylpyridinium and another compound, which was shown to be as 1-butyl-2-[(2-oxopiperidin-3-ylidene)methyl]pyridinium. Reaction of 18 with the C-H acidic 4-hydroxy-5-methylfuran-3(2H)-one leads to the formation of the condensation product 1-butyl-2-[hydroxy-(4-hydroxy-5-methyl-3-oxofuran-2(3H)-ylidene)methyl]-pyridinium.
authors.affiliation: Institute of Food Chemistry (170), University of Hohenheim, Garbenstr 28, D-70593 Stuttgart, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Reihl
authors.forename: Klaus M
authors.initials: KM
authors.lastname: Biemel
authors.forename: Markus O
authors.initials: MO
authors.lastname: Lederer
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schwack
mesh_terms: D000447:Aldehydes / Q000138:chemical synthesis* / Q000737:chemistry; D002247:Carbon Isotopes; D006601:Hexoses / Q000737:chemistry*; D007553:Isotope Labeling; D008239:Lysine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015416:Maillard Reaction; D015394:Molecular Structure; D011726:Pyridinium Compounds / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000447:Aldehydes; D002247:Carbon Isotopes; D006601:Hexoses; D011726:Pyridinium Compounds; D008239:Lysine