Next, is generating canonical representative (Fig. ) which is performed using RDKit "rdMolStandardize.CanoncialTautomer()" functionality with the "remove sp 3 stereo" and "remove bond stereo" settings set as 'False' and 'reassign stereo' set as 'True'. The isotopic hydrogens are also tracked during tautomerization. This step results in the unsalted canonical representation (UCR).