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Updated: Aug 4, 2026

Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
Kinetics of interaction of vanillin with amino acids and peptides in model systems
W Chobpattana1, I J Jeon, J S Smith
1Department of Animal Sciences and Industry, Kansas State University, Manhattan, Kansas 66506, USA.
Abstract:
Model systems were used to study the reaction kinetics of vanillin and pentalysine, lysine, glutathione, cysteine, aspartame, or phenylalanine (molar ratio 1:1) in phosphate buffer. The buffer pH was adjusted to the pK(a)(2) of the available alpha-amino group of each amino acid or peptide. Reductions of vanillin followed first-order kinetics at 55, 65, and 75 degrees C in the presence of each of the amino acids or peptides used. The reaction rates were accelerated as the temperature increased. The rate constants were highest for pentalysine followed by lysine, phenylalanine, glutathione/cysteine, and aspartame. The reduction of phenylalanine followed first-order kinetics, whereas the formation of its reaction product followed zero-order kinetics. The activation energy (E(a)) for the reaction ranged from 5.6 to 14.5 kcal/mol.
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