Synthesis of 1,2,3,4‐Tetrahydroisoquinoline‐3‐Carboxylic Acid‐Embedded Decapeptides: In Silico Studies and In Vitro Evaluation Against Breast Cancer

Cancer is a leading cause of mortality worldwide, which has led to further research in developing more effective therapeutics. We synthesized amphipathic cationic peptides incorporating 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic acid) into their backbones to explore their potential anticancer properties. The MCF-7 cell line was selected to evaluate cell viability, inhibition percentage, and cytotoxic effects of the synthesized decapeptides. The results suggested DEC-1 (IC₅₀ = 3.38 µM) to be the most potent candidate, showcasing antiproliferative activity similar to the standard drug tamoxifen (IC₅₀ = 2.68 µM). Structural characterization of the peptides confirmed the successful incorporation of Tic into the peptide backbones. The peptides were docked with xanthine oxidase (PDB ID: 2CKJ) and Nrf2 (Nuclear factor erythroid 2-related factor 2) inhibitor protein Keap-1 (PDB ID: 7Q6S), revealing strong binding interactions, particularly for DEC-1, having a binding score of nearly -8.864 kcal/mol-which is stronger than its reference ligand with Keap-1 protein-suggesting possible inhibitory roles in cancer cell proliferation and oxidative stress regulation. These promising findings indicate that the potent molecule DEC-1 can be taken for further studies and might lead to a potential therapeutic agent for cancer treatment.