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.
Levorphanol in which a hydrogen at position 14 of the morphinan skeleton is substituted by hydroxy and one of the hydrogens of the N-methyl group is substituted by cyclopropyl. A semi-synthetic opioid agonist-antagonist analgesic, it is used as its (S,S)-tartaric acid salt for relief or moderate to severe pain.