The isomeric SMILES representation of the molecules is transformed into a bit-vector using extended-connectivity fingerprints (ECFPs) algorithm. We used RDKit package to rapidly calculate ECFPs. In general, they work by circularly analyzing the environment of each atom and, then, hashing the information to create the fingerprints (FPs). A radius of 3 nearest neighbors was used. Chirality was also considered for the FP assessment. It is critical for backbone 2. The bit vector contains 0 and 1 with a length of 1024 for each molecule.