PubChem provides information on the biological activities of small molecules. It is a component of NIH's Molecular Library (free registration). PubChem includes substance information, compound structures, and BioActivity data in three primary databases: Pcsubstance, Pccompound, and PCBioAssay.
The Substance/Compound database, where possible, provides links to bioassay descriptions, literature, references, and assay data points. The BioAssay database also includes links back to the Substance/Compound database. PubChem is integrated with Entrez , NCBI's primary search engine, and also provides compound neighboring, sub/superstructure, similarity structure, bioactivity data, and other searching features.
PubChem contains substance and bioassay information from a multitude of depositors. -more-