Chemical Entities of Biological Interest (ChEBI) - Freely available dictionary of 'small molecular entities' (atoms, molecules, ions, ...), that are either products of nature or synthetic products used to intervene in the processes of living organisms.
Chemical Information Services, Inc. - Delivers information to the chemical and pharmaceutical industries for more than 30 years. Includes information on producers of all types of chemicals, users of bulk pharmaceuticals and chemical intermediates and holders of DMFs/VMFs and Certificates of Suitability.
Directory of Chemical Producers - Provides comprehensive information about basic chemical manufacturers and their products in over 60 countries.
ECOTOX Database System - Source for locating single chemical toxicity data for aquatic life, terrestrial plants and wildlife. Integrates three toxicology effects databases: AQUIRE, PHYTOTOX , and TERRETOX. Created by Environmental Protection Agency (EPA), USA.
Heterocycles Database - Free database of natural products with heterocyclic ring system (>29000) provided by The Japan Institute of Heterocyclic Chemistry, publisher of the journal Heterocycles.
Human Metabolome Database - Freely available database containing detailed information about small molecule metabolites found in the human body.
Infotherm - Thermophysical properties of mixtures (25000) and pure chemical compounds (6700). Many data free of charge.
IS-DB the International Spectroscopic Data Bank - Interactive free database collecting all types of spectroscopic data, from all spectroscopic techniques and from all disciplines (chemical, life, physical sciences).
NIST Scientific and Technical Databases - Chemistry - NIST has long been developing and compiling benchmark data for the properties of important substances, classes of substances and systems. It's data collections, data prediction methods and models meet high priority industrial and national needs.
SPRESIweb - Integrated scientific database developed by InfoChem. Combines a large chemical database (4.5 million molecules) with links to additional information sources. The search can be carried out for molecules, reactions and references.