ABSTRACT
Nonenzymatic modication of proteins has been implicated in the pathogenesis of diabetes, atherosclerosis, neurodegenerative diseases, and normal aging. The modi-cation can arise from direct exposure to reactive oxygen, chloride, or nitrogen species, and from reaction with low-molecular-weight reactive carbonyl species (RCS). The accumulation of various RCS derived from carbohydrates as well as their subsequently induced protein modication is proposed to constitute a state of “carbonyl stress.” These RCS are responsible for the formation of advanced glycation end products (AGEs), and their roles in the development of various age-related diseases have
4.1 Introduction .................................................................................................... 53 4.2 Chemical Mechanism for Formation ..............................................................54 4.3 Factor Affecting the Formation of Reactive Dicarbonyl Compounds and
Advanced Glycation End Products during Maillard Reaction ....................... 56 4.4 Toxic Effects ................................................................................................... 57
4.4.1 Risk of Diabetes .................................................................................. 57 4.5 Analytical Method for RCS ............................................................................ 58
4.5.1 High-Performance Liquid Chromatography....................................... 58 4.5.2 Gas Chromatography (GC) ................................................................. 59
4.6 Methodologies for Quantication of AGEs ....................................................60 4.6.1 Fluorescence .......................................................................................60 4.6.2 HPLC Methods ...................................................................................60 4.6.3 Liquid Chromatography-Tandem Mass Spectrometry Methods ........ 61
4.7 Possible Approaches to Control Levels of AGEs and RCS In Vivo and In Vitro ................................................................................................61 References ................................................................................................................ 63
been increasingly recognized. Carbohydrate-derived RCS include methylglyoxal (MGO), glyoxal (GO), and 3-deoxyglucosone (3-DG). Both RCS and AGEs can be formed endogenously (body) and exogenously (food) (Singh et al., 2001; Wang and Ho, 2012). RCS are reactive intermediates formed from the interaction of a carbonyl group mainly from reducing sugars with an amino group from proteins, peptides, and amino acids known as Maillard reaction. The Maillard reaction plays a very important role in food, and provides avor, aroma, and color to food during heating, processing, and storage (Wu et al., 2011). The carbonyl groups of RCS interact with proteins to form various AGEs or to crosslink proteins. This process induces carbonyl stress and causes proteins to lose their function, damage tissue, and accelerate cell dysfunction (Lesgardset al., 2011; Wu and Juurlink, 2002). More and more research studies show that RCS and AGEs are connected with diabetes and its complication, as well as age-related disorders, such as Alzheimer’s disease and atherosclerosis (Picklo et al., 2002; Ramasamy et al., 2012; Sena et al., 2012). RCS and AGEs can be found in food and biological system, and it is very important to develop standardized and accurate methods to analyze them.
