Natural Andrographolide Isolated from Andrographis paniculata as Potent Epileptic Agent : Spectroscopy, Molecular Structure, and Molecular Docking Investigation

In this study, a comparative experimental and theoretical investigation of the isolation, characterization, and molecular electronic investigation of natural andrographolide is reported. The studied compound was isolated form the extracts of A. paniculata and characterized by spectroscopic technique and compared with theoretically simulated spectroscopic data. Also, in-silico molecular docking investigation of the anti-epileptic potency of natural andrographolide is appraised by assessing its efficacy to bind with 1R9O receptor. All computations were achieved at the B3LYP/6-311++G(d,p) level of theory within the framework of density functional theory (DFT). A comprehensive study of the isomerization of natural andrographolide was also considered by conducting several potential energy surface scans for both ring and angle rotation. The results prompt that the cis-conformer is more unstable than the trans-conformer with energy barrier height of − 1156.603 kcal/mol lower than that obtained for the trans isomer. The molecular reactivity descriptors also divulged that natural andrographolide was considerably reactive and its reactivity and stability was observed to be influenced by different solvents polarity and permittivity. The molecular docking investigations also showed that natural andrographolide possesses substantial anti-epileptic activity in comparison with diazepam and thus, a potential pharmacophore for the development of efficient anti-epileptic agents.