the heterocyclic n-nitrosamines showed rat-liver microsome-mediated mutagenicity in the following descending order : n-nitrosomorpholine greater than n-nitrosopyrrolidine greater than n-nitrosopiperidine greater than n-nitroso-n'-methylpiperazine .
C0028197
nitrosamines
C0027253
n-nitrosopyrrolidine