Identification of a nitrosamino aldehyde and a nitrosamino acid resulting from beta-oxidation of N-nitrosodiethanolamine.
N-nitrosodiethanolamine is converted to N-(2-hydroxyethyl)-N-(formylmethyl)nitrosamine (EFMN) and N-(2-hydroxyethyl)-N-carboxymethyl) nitrosamine (ECMN) by rat S9 liver preparation as a result of beta-oxidation. The beta-oxidized metabolites were isolated and identified by gas chromatography-mass spectrometry (GC-MS) by comparison with authentic standards. An original gas chromatographic method with thermal energy detection was set up to measure both metabolites quantitatively. Under the experimental conditions described, when NAD+ was used as cofactor, about 1% of N-nitrosodiethanolamine (NDELA) was converted to EFMN and about half of the latter product was in turn converted to ECMN. The beta-nitrosamino aldehyde seems to transfer the nitroso moiety to other amino-compounds, even at physiological pH. The significance of the metabolic formation of EFMN in relation to the carcinogenicity of NDELA is discussed.
D000818:Animals; D001711:Biotransformation; D002273:Carcinogens / Q000378:metabolism*; D002849:Chromatography, Gas; D004052:Diethylnitrosamine / Q000031:analogs & derivatives / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D009602:Nitrosamines / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D002273:Carcinogens; D009602:Nitrosamines; C014129:N-nitrosodiethanolamine; D004052:Diethylnitrosamine; C038290:N-(2-hydroxyethyl)-N-carboxymethylnitrosamine; C042445:N-(2-hydroxyethyl)-N-(formylmethyl)nitrosamine