New Aspects of the Maillard Reaction in Foods and in the Human Body

Abstract

The reactions that occur during the cooking, baking, and preservation of foods of all kinds are of great importance for the production of aroma, taste, and color. However, more recently it has been shown that these reactions may be accompanied by a reduction in nutritive value and the formation of toxic compounds. For these reasons, the very complex reactions between reducing sugars and the free amino groups of amino acids or proteins, known as non-enzymatic browning or the Maillard reaction, have again caught the interest of chemists. The Maillard reaction came to be seen in a new light as it was realized that it actually occurred in the human body. As a general rule, the longer the half-life of a protein, the larger the amount of its Maillard products found, i.e., important factors are the 'age' or persistence of the protein in the body and the glucose concentration, particularly in diabetics. Many of the symptoms developed by diabetics resemble those of premature aging, which leads to the possibility that glucose, because of its reactivity towards proteins, is fundamentally involved in the normally slow progress of aging.

In Vitro Kinetic Studies of Formation of Antigenic Advanced Glycation End Products (AGEs)

“…Despite significant recent progress (71), advances in these directions have been very difficult to achieve in the last decade. Since the completion of our work, 7 however, a report by Ulrich and coworkers (72) has appeared that describes independent studies showing that certain dicarbonyl AGE cross-links may be chemically broken by a compound related to thiamine. These findings raise the intriguing possibility that such mechanisms may be relevant to the post-Amadori inhibition that we have discovered with at least thiamine pyrophosphate and possibly pyridoxamine.…”

“…Nonenzymatic protein glycation (glucosylation or glycosylation) by glucose is a complex cascade of condensations, rearrangements, fragmentations, and oxidative modifications that lead to poorly characterized heterogeneous products often collectively termed Advanced Glycation End Products or AGEs 1 (1)(2)(3)(4)(5)(6)(7). These very slow Maillard reactions are believed to underlie the pathogenesis of diabetes (8 -15) and possibly neurodegenerative amyloidal diseases such as Alzheimer's (16 -21).…”

Formation Pathways for Lysine-Arginine Cross-links Derived from Hexoses and Pentoses by Maillard Processes

“…Chromatographic parameters: injection volume 50 l; flow rate 0.4 ml/min; trifluoroacetic of DOGDIC 12a,b, DOPDIC 13a,b, and pentosinane 10a a a The arrows in the structural formulae indicate the characteristic carbon-proton long-range coupling connectivities from the gs-HMBC spectra. No absolute configuration was determined for the diastereoisomers 12a and b as well as 13a and b. Hydrogen/carbon assignment has been validated by 1 UV Spectroscopy-UV spectra were measured with a Perkin-Elmer (Ü berlingen, Germany) Lambda 2.…”

“…: 49 711 459 4095; Fax: 49 711 459 4096; E-mail: ledererm@uni-hohenheim.de. 1 The abbreviations used are: AGE, advanced glycation end product; AGOE, advanced glycoxidation end product; BSA, bovine serum albumin; COSY, correlation spectroscopy; 3-DOG, 3-deoxyglucosone; 3-DOP, 3-deoxypentosulose; DTPA, diethylenetriaminepentaacetic acid; gs-HMBC, gradient-selected heteronuclear multiple bond correlation; gs-HSQC, gradient-selected heteronuclear single quantum coherence; LC-(ESI)MS, coupled liquid chromatography -electrospray ionization mass spectrometry; LC-NMR, coupled liquid chromatography -nuclear magnetic resonance spectroscopy; MWCO, molecular weight cut-off; SIM, selected ion monitoring; TOCSY, total correlation spectroscopy; PBS, phosphate-buffered saline; DOGDIC 12, Fig. 1).…”

Pharmacological reversal of advanced glycation end-product-mediated protein crosslinking

“…It is well known that glucose reacts non-enzymatically with protein amino groups with eventual formation of covalent protein-protein crosslinks, which are called advanced glycation end-products (AGEs) [1]. Much work has been done to establish a causative association between this process and many of the pathological sequelae observed in diabetes mellitus, including LDL modification and the vascular changes which lead to atherosclerosis [2,3].…”