LIPID Metabolites And Pathways Strategy (LIPID MAPSĀ®) is a multi-institutional supported website and database that provides access to a large number of globally used lipidomics resources. (from LipidMaps website)
GNPS is a web-based mass spectrometry ecosystem that aims to be an open-access knowledge base for community-wide organization and sharing of raw, processed, or annotated fragmentation mass spectrometry data (MS/MS). (from the GNPS website)
BRENDA (The Comprehensive Enzyme Information System) is an information system representing one of the most comprehensive enzyme repositories. It is an electronic resource that comprises molecular and biochemical information on enzymes that have been classified by the IUBMB. (from the BRENDA Wikipedia page)
The METLIN Metabolite and Chemical Entity Database is the largest repository of experimental tandem mass spectrometry and neutral loss data acquired from standards. (from the METLIN Wikipedia page)
Reactome is a free online database of biological pathways. There are several Reactomes that concentrate on specific organisms, the largest of which is focused on human biology.
Chemical Entities of Biological Interest, also known as ChEBI is a chemical database and ontology of molecular entities focused on 'small' chemical compounds, that is part of the Open Biomedical Ontologies (OBO) effort at the European Bioinformatics Institute (EBI). (from the ChEBI Wikipedia page)
MetaboLights is a data repository founded in 2012 for cross-species and cross-platform metabolomic studies that provides primary research data and meta data for metabolomic studies as well as a knowledge base for properties of individual metabolites. (from the Metabolights Wikipedia page)
The Human Metabolome Database (HMDB) is a freely available electronic database containing detailed information about small molecule metabolites found in the human body. (from HMDB's website)
Initiated in 1995, KEGG (Kyoto Encyclopedia of Genes and Genomes) is a collection of databases dealing with genomes, biological pathways, diseases, drugs, and chemical substances. (from the KEGG Wikipedia page)