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.
An organic heterotricyclic compound resulting from the formal condensation of the oxo group of cytidine to the 2' position with loss of water to give the corresponding cyclic ether. A prodrug, it is metabolised to the antineoplastic agent cytarabine, so is used to maintain a more constant antineoplastic action.