Conversion of Amadori product of Maillard reaction to N^ϵ‐(carboxymethyl)lysine in alkaline condition

Abstract

N O -(carboxymethyl)lysine (CML) is known to be formed by oxidative cleavage of Amadori products between C-2 and C-3 of the carbohydrate chain. We report here that CML formation from Amadori compounds is highly accelerated under alkaline conditions. Incubation of glycated human serum albumin (HSA) in 0.1 N NaOH led to the formation of CML whereas glycated HSA reduced by NaCNBH Q or non-glycated HSA did not generate CML., a model compound of Amadori product, was converted to CML under alkaline conditions. CML level of human sera (n = 224) preincubated with 0.1 N NaOH correlated well with glycated albumin value (r = 0.912) and hemoglobin A1c (r = 0.797).z 1998 Federation of European Biochemical Societies.

Scavenger Receptor Class B Type I-mediated Reverse Cholesterol Transport Is Inhibited by Advanced Glycation End Products

“…The N ⑀ -(carboxymethyl) lysine content of AGE-BSA was 7.7 mol/mol of BSA (33). Nonglycated BSA was prepared as described previously (44). Briefly, 1.0 g of BSA was incubated with phenyl boronic acid resin (PBA-60, Amicon, Beverly, MA) in 800 ml of 0.5 M glycine/NaOH buffer containing 2% MgCl 2 (pH 8.5) for 2 h at room temperature.…”

Non Enzymatic Glycated Proteins in the Blood and Cardiovascular Disease

“…The AP can gradually undergo progressive dehydration, cyclization, oxidation and rearrangement to form complex AGE [14,16,17]. The reaction is not reversible, and once formed, the AGE slowly accumulated over the lifetime of the protein and do not return to normal when hyperglycemia is corrected [18,19]. In contrast, the AP, which are in equilibrium with glucose concentration, increase when blood glucose is high and return toward normal when the glucose level is normalized by treatment; moreover, they do not accumulate on stable tissue proteins over the years [15].…”

Use of 13C Labeling and NMR Spectroscopy for the Investigation of Degradation Pathways of Amadori Compounds

“…N e -Carboxymethylhippuryl-lysine (CM-HL) was synthesized according to the method reported in the literature. 12) Other reagents were purchased from Wako (Osaka, Japan). TLC was performed on Silica Gel 60 F 254 plate (Merck, Darmstadt, Germany) using detection with UV absorption and color-producing reagents for amino acids (ethanolic 0.2% ninhydrin) and sugars [a mixture of phenol (5 g), concentrated sulphuric acid (5 ml) and ethanol (95 ml)].…”

“…This technique is thus expected to provide information that is inaccessible by other methods and considered to be suitable for the investigation of complicated degradation pathways of Amadori compounds. Thus, in this study, a 13 C-labeled model Amadori compound, [1][2][3][4][5][6][7][8][9][10][11][12][13] C]N e -(1-deoxy-D-fructos-1-yl)hippuryl-lysine, was synthesized and degradation mixtures of the labeled compound under aerobic conditions analyzed using 13 C-NMR spectroscopy to investigate the potential of the 13 C-labeling and NMR approach.…”