Derivatization of Methylglyoxal for LC-ESI-MS Analysis-Stability and Relative Sensitivity of Different Derivatives.

Stefan Fritzsche,Claudia Birkemeyer,Andrej Frolov,Robby Rynek,Susan Billig,Olga Leuner,Elena Tarakhovskaya,Ramarao Abburi

doi:10.3390/molecules23112994

Abstract

The great research interest in the quantification of reactive carbonyl compounds (RCCs), such as methylglyoxal (MGO) in biological and environmental samples, is reflected by the fact that several publications have described specific strategies to perform this task. Thus, many reagents have also been reported for the derivatization of RCCs to effectively detect and quantify the resulting compounds using sensitive techniques such as liquid chromatography coupled with mass spectrometry (LC-MS). However, the choice of the derivatization protocol is not always clear, and a comparative evaluation is not feasible because detection limits from separate reports and determined with different instruments are hardly comparable. Consequently, for a systematic comparison, we tested 21 agents in one experimental setup for derivatization of RCCs prior to LC-MS analysis. This consisted of seven commonly employed reagents and 14 similar reagents, three of which were designed and synthesized by us. All reagents were probed for analytical responsiveness of the derivatives and stability of the reaction mixtures. The results showed that derivatives of 4-methoxyphenylenediamine and 3-methoxyphenylhydrazine—reported here for the first time for derivatization of RCCs—provided a particularly high responsiveness with ESI-MS detection. We applied the protocol to investigate MGO contamination of laboratory water and show successful quantification in a lipoxidation experiment. In summary, our results provide valuable information for scientists in establishing accurate analysis of RCCs.

Highlights

The research interest in the role of reactive carbonyl compounds (RCCs) for environmental and biomedical aspects has grown tremendously ever since their relevance for human metabolism was Molecules 2018, 23, 2994; doi:10.3390/molecules23112994 www.mdpi.com/journal/moleculesMolecules 2018, 23, x FOR PEER REVIEW firstOneof ofthe thebiologically biologicallymost most important representatives of this compound group firstdiscovered discovered [1,2,3].[1,2,3]
3a compares the change in response pattern of the protonated molecular example, Figure 3a compares the change in response pattern of the protonated molecularion ionof ofthe the phenylenediamines phenylenediamines(left)
Given the results we obtained with our test candidates, including 3-MPH, we developed synthesis routes leading to the corresponding permanently charged phenylhydrazine

Summary

Introduction

The research interest in the role of reactive carbonyl compounds (RCCs) for environmental and biomedical aspects has grown tremendously ever since their relevance for human metabolism was Molecules 2018, 23, 2994; doi:10.3390/molecules23112994 www.mdpi.com/journal/moleculesMolecules 2018, 23, x FOR PEER REVIEW firstOneof ofthe thebiologically biologicallymost most important representatives of this compound group firstdiscovered discovered [1,2,3].[1,2,3]. One important representatives of this compound group isismethylglyoxal (MGO), which has been suggested to be involved in many lifestyle diseases, such methylglyoxal (MGO), which has been suggested to be involved in many lifestyle diseases, such as as diabetes cancer [6],[6], aging [7,8] [7,8]. Reactive carbonyl compounds are usually formed from carbohydrate depression [10]. Reactive carbonyl compounds are usually formed and fromlipid metabolism [11,12], while in the environment, they may originate from degradation of volatile organic carbohydrate and lipid metabolism [11,12], while in the environment, they may originate from substances in the atmosphere, such as isoprene.

Methods

Results

Conclusion