N-nitroso-N-(3-keto-1,2-butadiol)-3'-nitrotyramine (NO-NTA) is a product of model browning system in the presence of sodium nitrite. In this study, the chemical structure is confirmed by spectral studies, including UV, mass, nuclear magnetic resonance and infrared. NO-NTA is strongly genotoxic to the rat hepatocyte and is moderately cytotoxic to mouse C3H10T1/2 cells. Results obtained in this study indicate that NO-NTA inflicted DNA damage by the formation of DNA adduct. Additionally, C3H10T1/2 cells are treated with NO-NTA and, following an addition of 12-O-tetradecanoylphorbol-13-acetate (TPA) as promotor, the increase of transformed foci indicates that NO-NTA could possibly be an initiator. The saturation density of the transformed C3H10T1/2 cell represents about 10-fold increase and grew in soft agar, indicating that NO-NTA is tumogenic. These results suggest that the formation of genotoxic agent of nitroso-derivatives nay take place in nitrite-containing food or in vivo by nitrosation following ingestion of tyrosine and glucose.
