Investigation of the molecular properties of Betanin-Natural Deep Eutectic Solvent complex using computational and experimental methods

Betanin has drawn the attention of researchers due to its anti-inflammatory activities and demonstrated hepatic safety in human cells, in addition to having food colorant, antimicrobial, antiviral and antioxidant agent. The present work aims to unravel the structural, physical, and chemical properties of the interaction between Natural Deep Eutectic Solvent consisting of Citric acid and Glycerol with Betanin through computational and experimental methods. The optimization and frequency of the individual monomers and their biomolecular complex are performed using the Density Functional Theory method at B3LYP/6–311++ G(d,p) level of theory. NBO analysis of the complex is carried out to understand the charge transfer mechanism. The Atoms in Molecules analysis confirms the intra and intermolecular charge transfer within the biomolecular complexes. The thermodynamic properties, quantum chemical properties, HOMO-LUMO energy gap, vibrational spectral data and Non-Linear Optical properties are calculated and analyzed the data. The low value of the HOMO-LUMO energy gap and high hyperpolarizability value indicate the complex's bioactive and chemical reactivity nature. The Fourier Transform Infrared Spectra (FTIR) and Raman spectra of the individual monomers and their complexes are recorded experimentally, analyzed, and compared to the theoretical spectral data. The experimentally observed wavenumbers are correlated with the theoretically observed wavenumbers. The molecular docking of the complex with the 5 kzw and 1v4 s protein receptors yields docking scores of –8.40 kcal/mol and -9.20 kcal/mol, respectively, confirming that the ligand has a higher potential binding affinity to the target protein receptor.