Nicotine-1’-N-oxide is a derivative of nicotine found in the leaves, stems, and roots of N. tabacum, N. affinis and N. sylvestris. Nicotine-1’-N-oxide has also been identified as a metabolite of nicotine in animals and in man. The metabolism of nicotine in man proceeds by alternative routes of oxidation of nitrogen to form nicotine-1’-N-oxide (both diastereomers) or cotinine.