The 1,2-dicarbonyl compounds have received extensive attention due to their high reactivity and toxicity in vitro and in vivo. Availability of scavenging compounds may facilitate development of efficient strategies for their control. The concept of in situ generation of carbonyl trapping agents is an intriguing proposition and has been demonstrated with amino acid tryptophan. Ability of indole to undergo electrophilic aromatic substitution reaction was studied in the past with methylglyoxal. To confirm the generality of this reaction, model systems containing indole and several 1,2-dicarbonyl compounds were prepared and reacted at room temperature (RT) and at 150 °C and analyzed by ESI-qTOF-MS/MS and isotopic labeling technique. Indole showed ability to capture all the tested 1,2-dicarbonyls. Longer chain 1,2-dicarbonyls showed higher temperature dependency than shorter chain in their reactivity towards indole. Furthermore, the ability of indole to scavenge Strecker aldehydes was also demonstrated in alanine/glucose and in a bread model systems using [13C-2]indole.
Keywords: 2,3-butanedione; 2,3-pentanedione; 3,4-hexanedione; Glycolaldehyde; Glyoxal; Methylglyoxal; Scavenging activity; Tryptophan; [(13)C-2]indole; isotopic labeling technique and qTOF-MS/MS analysis.
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