Nitrite-Reactive Phenols Present in Smoked Foods and Amino-Sugars Formed by the Maillard Reaction as Precursors of Genotoxic Arenediazonium Ions or Nitroso Compounds
The N-nitrosamides formed in the human stomach by interaction between nitrite and suitable amine precursors have therefore been suspected of playing an important role in gastric carcinogenesis. Several amines which show direct-acting genotoxicity, after nitrosation in vitro, have been identified in foods frequently consumed in high-risk areas for stomach cancer. Three samples of smoked meat products and three samples of Japanese smoked and dried fish products "Katsuo-bushi" also exhibited potent direct-acting genotoxicity. Treatment with nitrite under acidic conditions was required to elicit such genotoxicity and only a few samples exhibited even weak activity without nitrosation. This chapter describes a number of precursor compounds that, after reaction with nitrite, yield DNA-reactive arenediazonium intermediates or N-nitroso compounds. N-Nitrosated glycosyl-p-nitroaniline has been shown by Bognar and Puskas to decompose to arenediazonium cations through nonenzymatic hydrolysis. The chapter examines the genotoxicity of nitrosated amines that are formed during the Maillard reaction.