title: Spectrophotometric assay of superoxide anion formed in Maillard reaction based on highly water-soluble tetrazolium salt.
abstract: A novel highly water-soluble tetrazolium salt, WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate sodium salt), can be reduced to water-soluble formazan with a superoxide anion. Here, the WST-1 assay was applied to detect the superoxide anion generated during the Maillard reaction. A sample solution containing carbonyl compounds such as glyceraldehyde and glycolaldehyde (5 mM) and Na-acetyl-L-lysine (10 mM) was incubated for 2 days at 37 degrees C. The detection of a superoxide anion generated in the sample was performed by the WST-1 assay, and the result was compared with the cytochrome c assay. The reduction of WST-1 was almost perfectly (86-96%) inhibited by the addition of the superoxide dismutase (SOD). On the contrary, the reduction of cytochrome c was slightly (20-25%) inhibited by the addition of SOD. A similar result was observed for the addition of 4,5-dihydroxy-1,3-benzene disulfonic acid (Tiron). These results mean that the specificity of WST-1 to the superoxide anion was superior to that of cytochrome c. It was also possible to continuously monitor superoxide anion generation during the Maillard reaction by the coexistence of WST-1 in the reaction solution.
authors.affiliation: Department of Bioresources Science, Faculty ofAgriculture, Kochi University, Japan. hukeda@cc.kochi-u.ac.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ukeda
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shimamura
authors.forename: Mina
authors.initials: M
authors.lastname: Tsubouchi
authors.forename: Yumi
authors.initials: Y
authors.lastname: Harada
authors.forename: Yumi
authors.initials: Y
authors.lastname: Nakai
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Sawamura
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives* / Q000737:chemistry; D003574:Cytochrome c Group / Q000378:metabolism; D005985:Glyceraldehyde / Q000737:chemistry; D008239:Lysine / Q000031:analogs & derivatives* / Q000737:chemistry; D015416:Maillard Reaction; D012680:Sensitivity and Specificity; D012995:Solubility; D012996:Solutions / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods*; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000032:analysis* / Q000737:chemistry* / Q000378:metabolism; D013778:Tetrazolium Salts / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: C110656:2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium; D003574:Cytochrome c Group; D012996:Solutions; D013778:Tetrazolium Salts; D014867:Water; D013481:Superoxides; C002315:N(alpha)-acetyllysine; D005985:Glyceraldehyde; D013482:Superoxide Dismutase; D000079:Acetaldehyde; D008239:Lysine; C010972:glycolaldehyde