Kinetic investigation of the trapping of Nε-(carboxymethyl)lysine by 4-methylbenzoquinone: A new mechanism to control Nε-(carboxymethyl)lysine levels in foods

Yuting Li; Lin Li; Marianne N Lund; Bing Li; Yi Hu; Xia Zhang

doi:10.1016/j.foodchem.2017.09.144

Kinetic investigation of the trapping of Nε-(carboxymethyl)lysine by 4-methylbenzoquinone: A new mechanism to control Nε-(carboxymethyl)lysine levels in foods

Food Chem. 2018 Apr 1:244:25-28. doi: 10.1016/j.foodchem.2017.09.144. Epub 2017 Sep 29.

Authors

Yuting Li¹, Lin Li², Marianne N Lund³, Bing Li⁴, Yi Hu⁵, Xia Zhang⁶

Affiliations

¹ School of Food Science and Technology, South China University of Technology, Guangzhou 510640, China; School of Chemical Engineering and Energy Technology, Dongguan University of Technology, Dongguan 523808, China.
² School of Food Science and Technology, South China University of Technology, Guangzhou 510640, China; School of Chemical Engineering and Energy Technology, Dongguan University of Technology, Dongguan 523808, China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou 510640, China. Electronic address: felinli@scut.edu.cn.
³ Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark.
⁴ School of Food Science and Technology, South China University of Technology, Guangzhou 510640, China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou 510640, China. Electronic address: bli@scut.edu.cn.
⁵ School of Food Science and Technology, South China University of Technology, Guangzhou 510640, China.
⁶ School of Food Science and Technology, South China University of Technology, Guangzhou 510640, China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou 510640, China.

PMID: 29120778
DOI: 10.1016/j.foodchem.2017.09.144

Abstract

o-Benzoquinones, formed during oxidation of polyphenols, react with amines through a Michael addition. In the present study, the ability of 4-methylbenzoquinone (4MBQ) to trap Nε-(carboxymethyl)lysine (CML) through a Michael addition with the amine groups on CML was investigated at different pH values. Apparent second order rate constants (k₂) for the reaction of 4MBQ with CML were determined by stopped-flow spectrophotometry at 25 °C to be ∼0.0 M^-1 s^-1 at pH 5, 9.5 M^-1 s^-1 at pH 7, and 164.5 M^-1 s^-1 at pH 8 based on the loss of 4MBQ at 401 nm. The reaction between 4MBQ and CML generated coloured CML-quinone compounds via colourless CML-phenol species as identified by LC-ESI-MS/MS. These data provide evidence that CML formed during food production can be trapped by o-benzoquinones, which is a new mechanism by which polyphenols may be used to control CML levels in foods.

Keywords: Amine-quinone adducts; CML; Michael addition; O-Benzoquinone; Rate constants.

MeSH terms

Benzoquinones / chemistry*
Chromatography, Liquid
Food*
Glycation End Products, Advanced / chemistry*
Hydrogen-Ion Concentration
Kinetics
Lysine / analogs & derivatives*
Lysine / chemistry
Oxidation-Reduction
Spectrometry, Mass, Electrospray Ionization
Spectrophotometry, Ultraviolet
Tandem Mass Spectrometry

Substances

4-methylbenzoquinone
Benzoquinones
Glycation End Products, Advanced
N(6)-carboxymethyllysine
Lysine