What is ChEBI?

ChEBI, EMBL-EBI’s database of Chemical Entities of Biological Interest, is a freely available, manually annotated database of small molecular entities  (molecules not encoded by the genome, Figure 1). These could include any constitutionally or isotopically distinct atom, molecule, ion, ion pair, radical, radical ion, complex, conformer, or anything else that is a separately distinguishable entity.

ChEBI focuses on chemical nomenclature and structures, and provides a wide range of related chemical data such as formulae, links to other databases and an ontology for the chemical space. It aims to bridge the gap between small molecules and the macromolecules with which they interact in living systems.