LAUSR

Abstract Regular practice in tobacco farming recognizes that copper is one of the essential micronutrients in tobacco ( Nicotiana tabacum ). We report here that copper is present in significant levels in post-harvested, cured tobacco. Transition metals have been shown to catalyze the formation of nitrosamines from amines of which nicotine, the most sought-after component in tobacco, is a tertiary amine. We found, using the nicotine-copper model system, Cu 2+ facilitates nitrosamine formation. A mechanistically plausible route for this metal ion-mediated nitrosamine formation from alkaloids is the nicotine-Cu 2+ complex formation where Cu 2+ preferentially binds to the pyridine nitrogen of nicotine in a pH-dependent fashion. Knowing that tobacco also contains other alkaloids, e.g., anabasine and anatabine, Cu 2+ could also enhance the production of nitrosamines from other tobacco-specific alkaloids.