title: Mutagen formed from tryptophan reacted with sodium nitrite in acidic solution.
abstract: The reaction products from L-tryptophan treated with nitrite under acidic conditions were investigated for mutagenic activity with the Salmonella typhimurium his reversion assay and for DNA-damaging activity using the rec-assay. The diethyl ether extract of the reaction mixture showed 8 spots on thin-layer chromatography (TLC). One compound from the TLC had high mutagenic activity for TA98 without S9 mix, with little DNA-damaging activity. The mutagen was purified and identified by instrumental analysis as 2-hydroxy-(1-N-nitrosoindole)propionic acid (NIHP). The mutagenic activity of NIHP was determined by the induced mutation frequency method; the induced mutation frequency was about 19.2 X 10(-5) at a dose level of 160 micrograms/plate.
mesh_terms: D000143:Acids; D055598:Chemical Phenomena; D002621:Chemistry; D004249:DNA Damage; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009152:Mutagenicity Tests; D009153:Mutagens / Q000302:isolation & purification; D009573:Nitrites; D012486:Salmonella typhimurium / Q000187:drug effects; D014364:Tryptophan / Q000031:analogs & derivatives*
chemical_list: D000143:Acids; D009153:Mutagens; D009573:Nitrites; D014364:Tryptophan