Different types of data
If a chemical structure can be drawn for an entity, it will be shown in the top left-hand corner of the main ChEBI display page for the entity (see Figure 3 below). Structures of large or complex entities can be enlarged if desired by hovering the cursor over the structure. By default, the structure is shown as a still image; clicking in the ‘Dynamic applet' checkbox will open an applet enabling alternative displays of the structure to be selected.
Immediately underneath the structure, there are direct links to carry out the commands 'Find compounds which contain this structure', 'Find compounds which resemble this structure‘, or to ‘Take the structure to the Advanced Search’, which allows the structure to be used in conjunction with text and ontology searches.
To the right of the structure, the recommended ChEBI Name is shown, along with the ChEBI ID (a unique and stable identifier), an ontological definition, the 'star' status of the entry, and secondary IDs (i.e. identifiers of records that have been merged with the record; searching for any secondary ID will automatically find it and display the merged record).
If a Wikipedia article is available for the entity, the introductory paragraph of the article is shown in a 'Wikipedia' section underneath the structure, along with a link to the full article. Under this section, the molecular formula, charge, and molecular weight are shown, together with standard InChI, InChIKey, and SMILES line entry versions of the structure.
In addition to the recommended ChEBI name (to the right of the structure), various other names for an entity are listed in the lower half of the main display page, together with the resource in which they were found. The synonyms are divided into the following categories:
- IUPAC recommended name
- International Non-proprietary Names (INNs) - as designated by the World Health Organisation.
- Other synonyms
- Brand names (generally restricted to drug entries)
Where a non-English INN or other synonym is given, the language is indicated by the appropriate flag to the right of the name (Spanish, French and Latin in Figure 4 below).
Links to other databases and registry numbers
The 'Database Links' section of the main display page (beneath the 'Synonyms' section) provides links to other resources (Figure 5). The links have been selected by ChEBI curators as being particularly relevant to the ChEBI entity.
Some resources (e.g. ChemIDplus, NIST Chemistry WebBook) use Chemical Abstracts Service (CAS) registry numbers as their identifiers. In these cases, the links to the resources are provided in the 'Registry Numbers' section. In addition to CAS registry numbers, this section lists Beilstein, Reaxys and Gmelin registry numbers, as appropriate, together with the sources of this information.
At the bottom of the 'Database Links' section on the main display page for an entity is a link marked 'View more database links'. Clicking on this opens a separate display page (also accessible by clicking on the 'Automatic Xrefs' tab at the top of the page), where a series of automatically-generated cross-links are provided.
To return to the main display page, simply click on the 'Main' tab at the top of the page.
The 'Citations' section is found immediately below the 'Registry Numbers' section at the bottom of the main display page for an entity (Figure 6). Here, a list of selected references is provided, together with links for accessing the abstracts or full papers if desired.
Natural products data
ChEBI currently contains data for over 5 000 natural products. In addition to the chemical structure, nomenclature data, database links, registry numbers and citation information, the vast majority of these entries include detailed information on the source of the compound (species, strain, tissue type, etc, Figure 7). This information, which is fully searchable, is displayed on the main data page, along with links to appropriate taxonomies and ontologies, and is directly linked to references in the primary literature.