title: Mutagenicity studies on N-nitrosated products of the Maillard browning reaction: N-nitroso-fructose-amino acids.
abstract: The N-nitroso derivatives of D-fructose-L-glycine, D-fructose-L-alanine, D-fructose-L-phenylalanine, D-fructose-L-serine, Dfructose-L-aspartic acid and D-fructose-L-tryptophan (a mixture of alpha-N-nitroso-D-fructose-L-tryptophan and 'indolyl-nitrosamine'-D-fructose-L-tryptophan) were tested for mutagenicity in five auxotrophic strains of Salmonella typhimurium with and without metabolic activation (S-9 mix). The alanine, phenylalanine and aspartic acid compounds were not mutagenic. The glycine and serine compounds showed a very low but reproducible increase in the numbers of his+ revertants in strain TA1535 without S-9 mix. The mixture containing both nitrosated D-fructose-L-tryptophan compounds was mutagenic in all five strains, with or without metabolic activation. The alpha-N-nitroso-D-fructose-L-tryptophan component of the mixture, which is nitrosated at the amino group, was isolated and tested without S-9 mix. It was mutagenic in three strains. Unnitrosated D-fructose-L-amino acids, D-fructose, and the individual L-amino acids were non-mutagenic when tested under those conditions for which a positive response had been obtained with the corresponding nitrosated compounds. These results indicate the potential value of developing analytical methods to identify alpha-N-nitroso-D-fructose-L-tryptophan in food or food extracts that are to be screened for mutagenic components.
mesh_terms: D000596:Amino Acids / Q000633:toxicity*; D000606:Amino Sugars / Q000633:toxicity*; D000818:Animals; D001711:Biotransformation; D006358:Hot Temperature; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism; D008297:Male; D009152:Mutagenicity Tests; D009153:Mutagens; D009602:Nitrosamines / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains; D012486:Salmonella typhimurium / Q000235:genetics
chemical_list: D000596:Amino Acids; D000606:Amino Sugars; D009153:Mutagens; D009602:Nitrosamines