Table 4. Half-maximal inhibition (IC50) value of copper-catalyzed oxidation of ascorbic acid by the tested compoundsa

CompoundIC50 (μM)
a Ascorbic acid (500 μM) was incubated at 30°C with 500 nM CuCl2 in 50 mM phosphate buffer (pH 7.4) in the presence of several concentrations of the tested compounds. The contents of ascorbic acid in the incubation mixtures were determined by HPLC.
1H-Tetrazole7600
5-Phenyl-1H-tetrazole120
5-(4′-Methylbiphenyl-2-yl)-1H-tetrazol2
Olmesartan5
Temocaprilat110
Nifedipine280
Aminoguanidine4600
Pyridoxamine1100
OPB-91953