The three-dimensional structure of the HT1 protein was obtained from the Protein Data Bank (PDB ID: 8FYI). Ligand were downloaded from the Zinc20 Database , and approximately 5000 compounds were selected for virtual screening. The following are the Zinc Database Tranches settings that were used to download the ligands files: (1) only 3D models were selected; (2) in the reactivity section, "Standard" and "Exclusive" were chosen; (3) in purchasability, "In-Stock" and "Exclusive" options were selected; (4) Reference (R) pH was chosen; (5) Charge: "0"; and (6) "Lead-Like" compounds were selected. In the next step, ligands were selected based on LogP values. Since, chemical compounds with LogP=2 have good oral and intestinal absorption only these compounds were selected for virtual screening. Finally, the compounds were downloaded in pdbqt file format. The binding poses of ligands to the ZnT opening were explored using AutoDock Vina 1.5.6 software. For each protocol, 10 poses were generated for all four protein-substrate complexes.