2-(N-nitroso-N-methylamino)propiophenone, a direct acting bacterial mutagen found in nitrosated Ephedra altissima tea

A new N-nitroso compound identified in a nitrosated tea extract made from the plant Ephedra altissima and shown to be formed under in vivo conditions was identified as 2-(N-nitroso-N-methylamino)propiophenone (NMAP). N-Nitrosoephedrine (NEP), another N-nitroso compound detected in nitrosated Ephedra altissima tea and NMAP are shown to exert mutagenic activity in the Salmonella/mammalian microsome mutagenicity (Ames) test. Base-pair substitution mutation-detecting strains (TA100 and TA1535) showed both compounds to be weak direct-acting mutagens without the addition of S9-mix. The identification, synthesis and mutagenicity of NMAP are discussed.