Fig. 2 Absorbance change by WST-1 assay. Glyceraldehyde (5 mM), N ^a-acetyl-L-lysine (10 mM) and DTPA (50 mM) in 50 mM chelex-treated phosphate buffer (pH 7.0) were incubated for 2 days at 37��. The assay was performed in the absence (��) and presence (��) of SOD.