Chemical Entities of Biological Interest (ChEBI) is a freely available dictionary of molecular entities focused on ‘small’ chemical compounds.

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Example: iron*, InChI=1S/CH4O/c1-2/h2H,1H3, caffeine

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User Manual Learn more about the data fields in the ChEBI and data sources for ChEBI. If you are unable to access the online Google document, please use the FTP link to view our manuals.

Train Online Tutorial An online quick tour (0.5 h) and a more detailed tour (1 h) covering much of the material in the User Manual can be found on the EBI Train Online site here.

Statistics Graphs showing the growth of ChEBI, the numbers of curated, submitted and unchecked entries, the numbers of links to other resources and the sources of the information present in ChEBI



SDF files ChEBI provides its chemical structures and additional data in structure-data file (SDF) format.

Ontology files ChEBI ontology is provided in the W3C standard Web Ontology Language (OWL) and OBO formats.

Database files ChEBI is stored in a relational database and we currently provide the ChEBI tables in flat-file tab delimited format, as an Oracle binary dumps and a generic SQL dumps for MySQL and PostgreSQL database.


Entity of the month

2nd January 2019

Azidothymidine (CHEBI:10110, also known as AZT or zidovudine) was developed in 1964 as a potential anti-cancer agent by American scientist Dr Jerome Horwitz (1919 – 2012) at the Michigan Cancer Foundation (now the Barbara Ann Karmanos Cancer Institute) in Detroit [1]. AZT is a member of a group of compounds called dideoxythymidines which were designed to resemble nucleosides, the building blocks of DNA. In theory, these synthetic nucleosides would substitute themselves for natural nucleosides, and act as chain-terminators of DNA synthesis, so preventing the cancer cells from duplicating.

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