Characterization of potentially mutagenic products from the nitrosation of piperine

Piperine is the main pungent principle of pepper, a spice consumed by people all over the world. It is the trans-trans isomer of 1-piperoylpiperidine and contains the methylene dioxy moiety. It is known to give unidentified mutagenic products on reaction with nitrite. The nitrosation reaction of piperine is of concern as endogenous nitrosation could take place in the human stomach from ingested precursors, piperine and nitrite. Nitrites can be ingested directly by consuming cured foods or indirectly as nitrates, which could be converted to nitrites under appropriate conditions. We have nitrosated piperine using aqueous nitrous acid and have isolated and identified some N-nitroso and C-nitro compounds. Their isolation, characterization and potential mutagenicity has been discussed.