KEGG icon


Molecular building blocks of life in the chemical space

Enter C/G/R/RP/RC numbers      (Example) C00389 C05903 C06562 C08650 C09727 C09762

Chemical Substances and Reactions

KEGG LIGAND contains our knowledge on the universe of chemical substances and reactions that are relevant to life. It is a composite database consisting of COMPOUND, GLYCAN, REACTION, RPAIR, RCLASS, and ENZYME databases, whose entries are identified by C, G, R, RP, RC, and EC numbers, respectively. ENZYME is derived from the IUBMB/IUPAC Enzyme Nomenclature, but the others are internally developed and maintained.
Database Identifier Content Specialized
entry point
LIGAND COMPOUND C number Chemical compound structures KEGG COMPOUND
GLYCAN G number Glycan structures KEGG GLYCAN
REACTION R number Biochemical reactions KEGG REACTION
RPAIR RP number Reactant pair alignments
RCLASS RC number Reaction class
ENZYME EC number Enzyme nomenclature

blue Search for
bfind mode bget mode

LIGAND Relational Database

The primary database of KEGG LIGAND is a relational database with the KegDraw interface, which is used to generated the secondary (flat file) database for DBGET. A read-only copy of the LIGAND relational database is made publicly accessible.

blue Search COMPOUND
blue Search GLYCAN
blue Search REACTION
blue Search RPAIR

Chemical Structure Search

blue Search similar compound structures
SIMCOMP:maximal common subgraph search -- a portion of the query compound is optimally matched to a portion of the database compound [references]
SUBCOMP:isomorphic subgraph search -- the query compound is fully matched to a portion of the database compound (substructure match) or a portion of the query compound is fully matched to the database compound (superstructure match)
blue Search similar glycan structures
KCaM: local or global search for matching tree structures [reference]
blue Download chemical structure drawing tool
KegDraw:Java application for drawing chemical compound structures and glycan structures with the capabilities to search against the KEGG databases

Reaction Search and Prediction

blue Assign EC number from chemical structures
E-zyme:automatic assignment of EC numbers (at the sub-subclass level) for a given set of substrate-product pairs [references]
blue Predict and search reaction pathways
PathPred:prediction of biodegradation and biosynthetic pathways by matching against known subsets of RDM patterns [reference]
PathComp:search for possible reaction paths between two compounds based on the information of reactions, enzymes, or enzyme genes
PathSearch:search for similar reaction subpathways for a given set of R numbers, RP numbers, or RC numbers

Last updated: February 1, 2012
KEGG GenomeNet Kanehisa Laboratories