Mutagenic products are promoted in the nitrosation of tyramine.
Tyramine is a biogenic compound derived from the decarboxylation of the amino acid tyrosine, and is therefore present at important concentrations in a broad range of raw and fermented foods. Owing to its chemical properties, tyramine can react with nitrite, a common food additive, in the acidic medium of stomach to form N- and C-nitroso compounds. Since toxicology studies have shown that the product of C-nitrosation of tyramine is mutagenic, in the present article tyramine nitrosation mechanisms have been characterized in order to discern which of them are favoured under conditions similar to those in the human stomach lumen. To determine the kinetic course of nitrosation reactions, a systematic study of the nitrosation of ethylbenzene, phenethylamine, and tyramine was carried out, using UV-visible absorption spectroscopy. The results show that, under conditions mimicking those of the stomach lumen, the most favoured reaction in tyramine is C-nitrosation, which generates mutagenic products.
Departamento de Química Física, Universidad de Salamanca, Plaza de los Caídos, 1-5, E-37008 Salamanca, Spain.
Mario
M
González-Jiménez
Departamento de Química Física, Universidad de Salamanca, Plaza de los Caídos, 1-5, E-37008 Salamanca, Spain.
Jorge
J
Arenas-Valgañón
Departamento de Química Física, Universidad de Salamanca, Plaza de los Caídos, 1-5, E-37008 Salamanca, Spain.
María Del Pilar
Mdel P
García-Santos
Departamento de Química Física, Universidad de Salamanca, Plaza de los Caídos, 1-5, E-37008 Salamanca, Spain.
Emilio
E
Calle
Departamento de Química Física, Universidad de Salamanca, Plaza de los Caídos, 1-5, E-37008 Salamanca, Spain. Electronic address: jucali@usal.es.
Julio
J
Casado
D001555:Benzene Derivatives / Q000737:chemistry; D006801:Humans; D008962:Models, Theoretical; D009153:Mutagens / Q000737:chemistry*; D009573:Nitrites / Q000737:chemistry; D015538:Nitrosation; D009603:Nitroso Compounds / Q000737:chemistry; D010627:Phenethylamines / Q000737:chemistry; D013270:Stomach / Q000187:drug effects; D014439:Tyramine / Q000737:chemistry*
D001555:Benzene Derivatives; D009153:Mutagens; D009573:Nitrites; D009603:Nitroso Compounds; D010627:Phenethylamines; C029261:phenethylamine; C004912:ethylbenzene; D014439:Tyramine
Monoamines; Nitrosation reactions; Nitroso compounds; Tyramine