In Silico Study, Synthesis, and Quantitative Structure-Activity Relationship of N1-Benzoyl-N3-Naphthylthiourea and Its Derivatives as Anti-breast Cancer Agents Against the T47D Breast Cell Line

Breast cancer is the leading cause of cancer-related mortality among women worldwide. Conventional therapies such as surgery, radiation, and chemotherapy often affect normal cells in addition to cancer cells, highlighting the need for the development of selective anticancer agents. Thiourea derivatives are known for their cancer cell- targeted properties, exhibiting cytotoxicity against cancer cells while remaining non-toxic to normal (Vero) cells. This study aimed to develop and evaluate N1-benzoyl-N3-naphthylthiourea (BNTU) and 14 of its derivatives as potential breast cancer agents through in silico approaches, synthesis, and Quantitative Structure-Activity Relationship (QSAR) analysis. 

Molecular docking was performed using Molegro Virtual Docker (MVD) 5.5 on breast cancer-related protein targets: ERα (PDB 3DT3), ERβ (PDB 3OLL), PR (PDB 2OVH), and HER2 (PDB 3RCD), using the Rerank Score (RS) parameter. Statistical analysis revealed no significant differences among the four receptors, and Erα was selected as the representative target for the T47D cell line.  Physicochemical and ADMET properties were also predicted in silico. Based on the results, the parent compound BNTU and four derivatives were synthesized via nucleophilic substitution and addition reactions under microwave irradiation. FTIR, 1H-NMR, 13C-NMR, and ESI-MS/MS analyses confirmed the successful synthesis of BNTU, 4TBBNTU, 4CFBNTU, 3CFBNTU, and 4OCBNTU, with yields of 47.8%, 54.1%, 39.7%, 49.3%, and 51.3%, respectively.

Cytotoxicity assays using the MTT method on T47D cells revealed that BNTU (IC50 217.45 μM) exhibited higher activity than its four derivatives. Two compounds (BNTU and 4TBBNTU) showed greater toxicity than hydroxyurea, whereas the remaining derivatives demonstrated lower activity. The best QSAR equation obtained indicated that the electronic parameter EHOMO significantly influenced the cytotoxic activity of the compounds.

Keywords: N1-benzoyl-N3-naphthylthiourea; in silico; synthesis; cytotoxic activity; T47D; QSAR