Influence of pro- and antioxidants on the formation of mutagenic-carcinogenic heterocyclic amines in a model system

The precursors of the heterocyclic amines (HAs), creatinine, glycine and glucose, were heated with the addition of different iron and copper compounds, hydroquinone, corn oil, β-carotene, tocopherols and synthetic antioxidants. The yield of HAs in the model system was affected by added pro- and antioxidants, while the species formed were not. Most of the antioxidants, as well as different forms of iron, were shown to increase the amount of 2-amino-3,8-dimethylimidazo[4,5-f]-quinoxaline (MeIQx) formed in the model system. Copper had no effect on the formation of MeIQx. Hydroquinone had only a small increasing effect but, in combination with iron sulphate, an extreme increase in MeIQx, 2-amino-3-methylimidazo[4,5-f]quinoxaline (IQx) and 2-amino-3,7,8-trimethylimidazo[4,5-f]-quinoxaline (7,8-DiMeIQx) formation was observed. β-carotene and γ-toco-pherol were shown to inhibit the synergistic effect of hydroquinone and iron sulphate, but had less effect in model mixtures containing none or only one of the pro-oxidants.