External databases

ChEMBL - an open data database containing binding, functional and ADMET information for a large number of drug-like bioactive compounds

ChemSpider - a free chemical structure database providing fast text and structure search access to over 32 million structures from hundreds of data sources

DACS - a database of available chemical substances

PubChem - a database providing information on the biological activities of small molecules

ZINC - a free database of commercially-available compounds for virtual screening