Transformations of bioactive peptides in the presence of sugars—Characterization and stability studies of the adducts generated via the Maillard reaction

Metal-Binding Ability of Leu-Enkephalin, Related Glycoconjugates and Peptidomimetics

“…3) was obtained as described by Roščić and Horvat (2006). [34] (5) was obtained as described by Horvat et al (2007).…”

“…[34] (5) was obtained as described by Horvat et al (2007). [33] All compounds were desalted using an octadecylsilica solid-phase extraction (SPE) cartridge (500 mg, 2.8 mL).…”

Formation of the peptide-specific imidazolidin-4-one moiety in alanine containing Maillard reaction mixtures

“…Various Maillard reaction generated heterocyclic compounds have been identified in foods and model systems, however, the formation of imidazolidin-4-one moiety during Maillard reaction is only reported in peptide based model systems containing hexose sugars (Horvat, Varga-Defterdarovic, & Horvat, 1998;Roščić & Horvat, 2006;Roščić , Versluis, Kleinnijenhuis, Horvat, & Heck, 2001). The Schiff bases formed at the N-terminal amino acids in these systems were shown (Roščić & Horvat, 2006) to undergo, in addition to Amadori rearrangement, a nucleophilic attack by the amide-nitrogen atom of the neighbouring amino acid to form the imidazolidin-4-one moiety (see Fig.…”

“…The Schiff bases formed at the N-terminal amino acids in these systems were shown (Roščić & Horvat, 2006) to undergo, in addition to Amadori rearrangement, a nucleophilic attack by the amide-nitrogen atom of the neighbouring amino acid to form the imidazolidin-4-one moiety (see Fig. 1).…”

Glycosylation of lysine-containing pentapeptides by glucuronic acid: new insights into the Maillard reaction

“…1,2 Most interest has been directed towards glycosylation of proteins by glucose and its potential role in diabetes and aging, 3 but an increasing number of studies have been conducted with other reducing sugars, providing evidence that they may also react with peptides or proteins through the glycosylation pathway. [4][5][6] In spite of its relatively low concentration compared to glucose in vivo, D-glucuronic acid (GlcA) is a reducing sugar of biological importance due to its participation in the metabolism of many drugs and endogenous compounds. 7 A major metabolic pathway for the biotransformation of exogenous and endogenous carboxylic acid substrates is conjugation with endogenous GlcA to yield acyl glucuronide metabolites implicated in a wide range of adverse drug effects.…”