In OEChem TK, the term canonical SMILES is used for a unique SMILES string that encodes the connection table of a molecule, but no chiral or isotopic information. Consequently, two stereoisomers always share the same canonical SMILES, since their stereo information ignored during the canonicalization process. For generating a canonical SMILES, use the OECreateCanSmiString function.
OEChem TK‘s canonical SMILES terminology corresponds to Daylight‘s ‘unique‘ SMILES definition.
In OEChem TK, the name canonical isomeric SMILES is used for a unique SMILES string that also encodes isotopic and stereo information. Due to the unambiguity of canonical isomeric SMILES, they can be used as a universal identifier for a specific chemical structure. For generating a canonical isomeric SMILES, use the OECreateIsoSmiString function.
OEChem TK‘s canonical isomeric SMILES terminology corresponds to Daylight‘s ‘absolute‘ SMILES definition.
LINGO is a very fast text-based molecular similarity search method. It is based on fragmentation of canonical isomeric SMILES strings into overlapping substrings.
MACCS is a 166 bit-long structural key descriptor in which each bit is associated with a specific structural pattern.