Released in 2004, this resource provides information on the biological activities of small molecules. It includes substance information, compound structures, and BioActivity data in three primary databases:
- PubChem Substance - contains chemical structures, synonyms, registration IDs, description, related urls, database cross-reference links to PubMed, protein 3D structures, and biological screening results. If the contents of a chemical sample are known, the description includes links to PubChem Compound.
- PubChem Compound - contains validated chemical depiction information provided to describe substances in PubChem Substance. Structures stored within PubChem Compounds are pre-clustered and cross-referenced by identity and similarity groups. Additionally, calculated properties and descriptors are available for searching and filtering of chemical structures.
- PubChem BioAssay - contains bioactivity screens of chemical substances described in PubChem Substance. It provides searchable descriptions of each bioassay, including descriptions of the conditions and readouts specific to that screening procedure.
Results are displayed in three category pages: substance, compound, and BioAssay pages. They provide rich cross links to each PubChem database, other NCBI databases, and depositor’s databases. PubChem also provides a fast chemical structure similarity search tool.