Varoujan A. Yaylayan
McGill University
Analytical chemistryAmadori rearrangementNuclear chemistryGlycationMedicinal chemistryFourier transform infrared spectroscopyMass spectrometryOrganic chemistryChemistrySchiff baseGlycolaldehydeGlycineAlanineDecarboxylationMaillard reactionChromatographyExtraction (chemistry)Amino acidBiochemistryReaction mechanismStereochemistryHydrolysis
166Publications
38H-index
4,050Citations
Publications 165
Newest
#1Haoran Xing (McGill University)H-Index: 3
#2Varoujan A. Yaylayan (McGill University)H-Index: 38
With the emergence of mechanochemistry as a fast and efficient synthetic methodology, we reported earlier that ball milling of glucose with histidine leads to the formation of reaction mixtures rich in Schiff bases. Upon subsequent thermal treatments, these mixtures exhibited enhanced reactivity generating more browning and pyrazine-rich volatiles, compared to non-milled samples. To rationalize these observations, we further investigated the mechanochemistry of the Maillard reaction using glycol...
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#1Eun Sil Kim (McGill University)H-Index: 1
#2Varoujan A. Yaylayan (McGill University)H-Index: 38
Abstract Due to their high reactivities and short half-lives, the detection of Maillard reaction intermediates is relatively difficult to achieve in a single analytical run. In this study, the formation of Maillard reaction intermediates from heated alanine/glucose mixtures (110 °C for 2 h) was investigated through their complexation with divalent iron using electrospray ionization/quadrupole time-of-flight mass spectrometry and isotope labeling techniques. Analysis of the mixtures indicated tha...
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Abstract The ability of histidine to scavenge sugar-derived 1,2-dicarbonyl compounds was investigated using aqueous methanolic model systems containing histidine or histamine in the presence of glucose, methylglyoxal, or glyoxal. The samples were prepared either at room temperature (RT) or at 150 °C and analyzed using ESI-qTOF-MS/MS and isotope labeling technique. Replacing glucose with [U-13C6]glucose allowed the identification of glucose carbon atoms incorporated in the products. Various sugar...
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#1Wut Hmone Phue (McGill University)H-Index: 3
#2Divya Srinivasan (McGill University)H-Index: 2
Last. Saji George (McGill University)H-Index: 32
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#1Yi Yao Li (McGill University)
#2Varoujan A. Yaylayan (McGill University)H-Index: 38
Last. Claude Gariépy (AAFC: Agriculture and Agri-Food Canada)H-Index: 23
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Muscle carnosine represents an important health advantage of meat. Ground pork samples with intrinsic or added carnosine; fat content; and cooked under low or high intensity as a 2 × 2 × 2 factorial were digested in-vitro. Changes in free carnosine and in markers of lipid (hexanal, 4-hydroxynonenal (4-HNE), malondialdehyde (MDA) and protein (protein-carbonyls, thiols) oxidation, and of advanced glycation end-products (AGEs) Ne -(carboxymethyl)lysine (CML) were determined in the saliva, gastric, ...
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#1Haoran Xing (McGill University)H-Index: 3
#2Varoujan A. Yaylayan (McGill University)H-Index: 38
Mechanochemistry is gaining increasing interest as an efficient tool for solvent-free organic transformations. Recently, it was applied to perform the Maillard reaction of glucose with various amino acids that lead to the selective formation of Schiff bases and their Amadori rearrangement products. In this study, we report the thermal properties of the mechanochemically generated glucose–histidine reaction mixtures. Direct video recordings of their melting behavior show that the browning of the ...
2 CitationsSource
#1Eun Sil Kim (McGill University)H-Index: 1
#2Varoujan A. Yaylayan (McGill University)H-Index: 38
Abstract Sugar degradation products generated through thermal treatment of foods are considered the key precursors for various flavor compounds, toxicants and browning, but their high reactivity makes their detection difficult. In this study, a convenient analytical procedure for profiling of various reactive sugar intermediates having enediol or α -dicarbonyl moieties through complexation with divalent metal ions combined with electrospray ionization/quadrupole time-of-flight mass spectrometry ...
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#1Raheleh Ghassem Zadeh (McGill University)H-Index: 2
#2Varoujan A. Yaylayan (McGill University)H-Index: 38
Abstract The 1,2-dicarbonyl compounds have received extensive attention due to their high reactivity and toxicity in vitro and in vivo. Availability of such 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 meth...
1 CitationsSource
#1Haoran Xing (McGill University)H-Index: 3
#2Varoujan A. Yaylayan (McGill University)H-Index: 38
Abstract The use of tandem mass spectrometry under positive ionization mode was previously developed as a tool for distinguishing isomeric Schiff bases and Amadori products. In this paper, similar diagnostic MS/MS fragmentation patterns were identified under negative ionization mode and was utilized to study the composition of mechanochemically generated Maillard reaction mixtures. The major diagnostic ion of the Schiff base was found to be a diose attached to the amino acid residue, while that ...
3 CitationsSource
#1Haoran Xing (McGill University)H-Index: 3
#2Valeri V. Mossine (MU: University of Missouri)H-Index: 19
Last. Varoujan A. Yaylayan (McGill University)H-Index: 38
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Schiff bases, the Amadori and Heyns rearrangement products are the most important isomeric intermediates involved in the early Maillard reaction; distinguishing between them by analytical mass spectroscopic techniques remains a challenge. Here we demonstrate that MS/MS fragmentation patterns can be used for the discrimination between glucose derived Schiff bases, Amadori, and Heyns compounds with glycine. An ESI-qTOF-MS system operated in the positive mode under both acidic and neutral condition...
4 CitationsSource