The Chemical Entities of Biological Interest (ChEBI) ontology is downloaded weekly from EMBL-EBI at http://www.ebi.ac.uk/chebi/. The data is made available under the Creative Commons License (CC BY 3.0, http://creativecommons.org/licenses/by/3.0/). For more information see: Degtyarenko et al. (2008) ChEBI: a database and ontology for chemical entities of biological interest. Nucleic Acids Res. 36, D344–D350.
A nitrosamine that is piperidine in which the hydrogen attached to the nitrogen is replaced by a nitroso group. One of the many carcinogens detected in cigarette smoke, it is found in meat, cheese and spices that have been treated with the preservative sodium nitrite.