Glyoxal formation by Fenton-induced degradation of carbohydrates and related compounds

摘要

In this paper,we provide a systematic analysis of glyoxal(1)formation from a range of monosaccharides and related compounds,to determine their potential role as sources of this alpha-oxoaldehyde in vivo.Substrates were reacted with the Fenton reagent(Fe~(2+)/EDTA/H_2O_2)and the mixtures were analyzed by HPLC using the 6-hydroxy-2,4,5-triaminopyrimidine fluorimetric assay.The rank order of hexoses and their derivatives as glyoxal sources was found to be fructose > glucose = mannose = galac-tose > glucose-6-phosphate > mannitol.Within the pentose group,arabinose and ribose gave the higher yields of 1 followed by deoxyribose and its adenine N-glycosides and ribulose.Among the tested substrates,three-carbon compounds,that is,trioses and glycerol,but not glyceraldehyde-3-phosphate,were by far the most effective sources of 1.The effects of H_2O_2 and Fe~(2+)/EDTA concentrations as well as of other metal ions were also investigated.