Investigation on structural, spectroscopic, DFT, biological activity and molecular docking simulation of essential oil Gamma-Terpinene

Abstract

Density functional theory (DFT) quantum chemical computations were used to explore the structural and spectroscopic characteristics of the Gamma terpinene molecule in this study. The inhibitory nature of the title chemical was revealed via molecular docking research. The optimization was conducted out through the DFT/B3LYP approach with the basis set 6-311++G(d,p). Molecular docking research was used to assess the anticancer activity of the Gamma terpinene molecule. The vibrational frequencies were allocated and compared to the empirically measured vibrational frequencies using the optimized molecular structure. The ultraviolet-visible spectrum was modeled and experimentally validated. Simulated computations of the molecular electrostatic potential surface were also performed to analyze the reactive behavior of the Gamma terpinene molecule. The stability and molecular reactivity of the molecule were computed using the HOMO-LUMO energies, energy gap, chemical potential (μ), electronegativity (χ), hardness (η), and softness (S) values. Natural bond orbital analysis has been used to obtain the molecule's second order perturbation energy E(2) values, which show the bioactivity of the Gamma terpinene molecule. The molecule's reactive site is confirmed by the Mulliken atomic charge distribution and total electron density plotted with the molecular electrostatic potential surface analysis. The in vitro investigation through disc diffusion method was used to assess gamma-terpinene's antibacterial and antifungal activity, while in silico analysis through molecular docking and pharmacokinetic evaluation was used to assess its anti-cancer activity and drug-likeness property. In anti-bacterial and anti-fungal analysis zones of clearance was observed at different concentrations and the highest binding affinity was observed against the breast cancer target protein ERα with a docking score of -6.6Kcal/mol.