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 nucleobase analogue that is uracil substituted with a (1-deoxy-D-ribityl)methyl group at position 6 and a (1E)-3-oxobut-1-en-1-yl group at position 5; one of 20 modifications to the potent microbial riboflavin-based metabolite antigen 5-(2-oxopropylideneamino)-6-D-ribityl aminouracil (5-OP-RU), an activator of mucosal-associated invariant T (MAIT) cells when presented by the MR1 protein (reported in MED:32123373).