Computational and Spectroscopic Investigation of Dl‐Methionine as a Potential Anti‐Breast Cancer Agent

Abstract The structural and vibrational characteristics of DL‐Methionine (DL‐MT), a possible anticancer drug, were examined utilizing experimental IR spectra and UV–vis spectra as well as theoretical calculations based on DFT. For optimized geometries, harmonic vibrational wavenumbers at the B3LYP/6–311++G(d,p) level were gauged. Vibrational spectrum assignments were obtained by utilizing normal coordinate analysis (NCA) in conjunction with Pulay's SQMFF methodology to precisely correlate theoretical wavenumbers with experimental data. A comparison of DL‐MT's FMO energy gap in dissimilar solvents revealed values of 5.586 eV (water), 5.608 eV (gas), 5.577 eV (methanol), and 5.581 eV (DMSO), which exhibits higher reactivity in water. MEP visualizations were generated, to predicted sites of electrophilic/nucleophilic reactivity in both gas and liquid phases (DMSO, methanol, water). Additional insights into electron‐hole distributions for excited states and topological studies (AIM, DORI, RDG, ELF, and LOL) were also explored. ADMET predictions and drug similarity analyses were executed to assess the compound's biological activity. With binding energies of −5.96, −4.51, −4.89, and −4.27 kcal/mol, respectively, the anti‐breast cancer proteins 5NW, 5NQR, 7ULV, and 6SZQ were targeted utilizing molecular docking approaches, and the interactions that accompanied these targets were comprehensively examined. Specifically, MD simulations with an all‐atom time of 100 ns were executed on the DL‐MT complexed with proteins 5NWH and 7ULV, which exhibited highest binding affinities. “Using the gmx_MMPBSA program on MD trajectory, binding free energies (ΔG binding )” of the protein‐ligand complexes were calculated and found to be −20.95 kcal/mol for 5NWH and −0.58 kcal/mol for 7ULV. These results point to DL‐Methionine as a potential substitute medicinal agent for the therapy of breast cancer.