Molecular Modeling of the Spectroscopic, Structural, and Bioactive Potential of Tetrahydropalmatine: Insight from Experimental and Theoretical Approach

Tetrahydropalmatine have been experimentally reported to have promising biological applications, although detailed theoretical investigation on its structural activities regarding its potency as a potential anti-inflammatory drug candidate has not been reported. In that regard, this present work focuses on the experimental and theoretical investigation of tetrahydropalmatine. The studied structure was experimentally isolated followed by detailed theoretical calculations within the framework of density functional theory (DFT) employing the 6-311++G(d,p) basis set. Theoretical and experimental characterization of the structure was observed to agree as different functional groups were analyzed. Molecular electronic properties of the isolated compound were investigated using five different functionals: B3LYP, PBE0, TPSSTPSS, M06-2X, and wB97XD for comparative purposes which present isolated structure to be more reactive at PBE0 and more stable geometry at wB97XD levels of theory. The most intense interaction from perturbation energy analysis was from δ (Formula presented.) * from PBEO with a stabilization energy of 108120.75 kcal/mol. The anti-inflammatory activity of the studied compound was investigated using the molecular docking simulations from which the results revealed that the proteins with PDB IDs: 4Z69, 5V0V, 6U4X, and 6U5A possess best pose binding affinities of −7.6, −6.8, −6.6 and −6.4 kcal/mol respectively.