The last step is removing isotopes and stereo annotations from compounds (Fig. ) which is performed using RDKit "rdMolStandardize.IsotopeParent()" and "Chem.RemoveStereoChemistry()" functionalities. In canSARchem this step is completed through the ChemAxon Standardizer node, and results in the abstract representation of a compound. This change from the ChemAxon to RDKit further reduces the dependence on commercial software.