ChemSpider

Chemspider is a chemical database. The system was first launched in March 2007 in a beta release form.

Database
The database contains 16.5 million unique molecules from the following sources
 * A-L: EPA DSSTox, FDA, Human Metabolome Database, Journal of Heterocyclic Chemistry, KEGG, KUMGM, LeadScope, LipidMAPS
 * M-N: Marinlit, MDPI, MICAD, MLSMR, MMDB, MOLI, MTDP, Nanogen, Nature Chemical Biology, NCGC, NIAID, NIH/NLM, NINDS Approved Drug Screening Program, NIST, NIST Chemistry WebBook, NMMLSC, NMRShiftDB
 * P-S: PANACHE, PCMD, PDSP, Peptides, Prous Science Drugs of the Future, QSAR, R&D Chemicals, San Diego Center for Chemical Genomics, SGCOxCompounds, SGCStoCompounds, SMID, Specs, Structural Genomics Consortium, SureChem, Synthon-Lab
 * T-Z: Thomson Pharma, Total TOSLab Building-Blocks, UM-BBD, UPCMLD, UsefulChem, Web of Science, xPharm, ZINC

The database can be updated with user contributions including chemical structure deposition, spectra deposition and user curation.

Searching
A number of available search modules are provided
 * The standard search allows querying for systematic names, trade names and synonyms and registry numbers
 * The advanced search allows interactive searching by chemical structure, chemical substructure, using also molecular formula and molecular weight range, CAS numbers, suppliers, etc. The search can be used to widen or restrict already found results.

Services
A number of services are made available online. These include the conversion of chemical names to chemical structures, the generation of SMILES and InChI strings as well as the prediction of many physicochemical parameters.