Chemical Name

Searches for structures containing a particular small molecule (e.g. biotin), using the small molecule names found in the Chemical Component Dictionary (formerly the HET Group Dictionary).

The chemical name search can be used to find a piece of text in the name or synonym of a chemical component as:

  • Contains: the text is contained in one of the names or the synonyms
  • Equals: the text matches exactly one of the names or synonyms
  • Sounds like: the text is a close match (and sounds similar) to one of the names or synonyms in full (will not match words contained in them)

The polymeric type option can be used to specify the context where the chemical component is used:

  • Free: in entries where it is not part of a polymeric chain of a protein or nucleic acid
  • Polymeric: in entries where it is part of a chain. Standard amino acids and nucleotides are excluded and can only be searched as free ligands
  • Any: in any of the cases listed above


  1. Equals: biotin, PolymericType:free (finds an exact match for the word biotin in names or synonyms of free ligands)
  2. Contains: monophosphate (finds chemical names that contain the string monophosphate either in free ligands or modified polymeric residues)