Pyrroles as effective agents for blocking amine nitrosation.
The ability of 10 pyrroles to block the acidic nitrosation of morpholine has been determined by using an assay that measures their effectiveness in the presence of a 10-fold excess of amine. The log (% N-nitrosomorpholine) formed is a linear function of blocking agent concentrations ranging from 0.0 to 1.5 times the equivalents of initial nitrite. The negative slopes of these plots allow a ranking of the effectiveness of the blocking agent. Several of the pyrroles have been found to be much more effective than established blocking agents such as ascorbic acid. The following order of blocking ability has been determined: 2,5-dimethylpyrrole = 1-benzyl-2,5-dimethylpyrrole much greater than 4-methylcatechol greater than ascorbic acid = 1,2-phenylenediamine = pyrrole greater than 1,2,5-tribenzylpyrrole = 1-benzylpyrrole = octamethylporphine much greater than ammonium sulfamate = hydrazine = 2,5-diphenylpyrrole much much greater than beta-nicotyrine greater than 2-pyrrolecarboxylic acid. Pyrroles give complex mixtures devoid of N-nitroso compounds upon nitrosation.
Wilcox
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Department of Chemistry, University of Missouri, Columbia 65211.
Bao
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YT
Loeppky
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D000588:Amines / Q000737:chemistry* / Q000378:metabolism; D009602:Nitrosamines / Q000138:chemical synthesis* / Q000378:metabolism; D015538:Nitrosation / Q000187:drug effects; D010636:Phenols / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry*; D013329:Structure-Activity Relationship
D000588:Amines; D009602:Nitrosamines; D010636:Phenols; D011758:Pyrroles