Spectroscopic, Quantum Chemical and Molecular Docking Studies on N-(9H-Purin-6-yl) Benzamide: A Potent Antimalarial Agent

Abstract

This study presents a comprehensive analysis of N-(9H-purin-6-yl) Benzamide (NPB) using a combination of Density Functional Theory (DFT) calculations and experimental techniques. The molecular configuration of NPB was optimized using DFT/B3LYP method employing the 6-311++G (d,p) basis set. The fundamental frequencies were calculated and assigned, which agree well with the experimental results. The UV-Vis spectroscopic analyses, HOMO-LUMO energy gap assessment, Molecular Electrostatic Potential calculation, and Mulliken charge analysis, Fukui function calculation and Natural bond orbital analysis were performed for the NPB molecule. The UV-Visible spectral analysis, which predicts the transition of bonding and anti-bonding π-electrons from the purine ring to the aromatic ring of the NPB molecule. A smaller energy gap in the HOMO-LUMO analysis reveals that the NPB molecule is more reactive and Mulliken atomic charge distribution analysis indicates that the carbon atoms are highly influenced by their substituents. Natural Bond Orbital (NBO) analysis was employed to investigate the bonding within the NPB molecule. The Fukui function analysis indicates that the biological activity of the NPB molecule. In order to analyze the structure of NPB molecule, the thermodynamic properties in the temperature range 100–1000 K were obtained by thermodynamic analysis software SHERMO calculator. The molecular docking analysis was carried out for antimalarial proteins (5ZNC, 2BMA, 7E27, 7E26) using auto-docking simulations. This computational method confirms the bioactivity and drug-likeness parameters of the NPB molecule. The molecular docking results predicts the formation of hydrogen bonds between the ligand (NPB) and the protein receptors. Based on these findings, this study establishes that the distinctive methodology applied to identify NPB molecule as a potential candidate for an antimalarial drug designing, which is suitable for in vivo and in vitro investigations.

Keywords:

• Vibrational spectral analysis
• ultraviolet-visible spectral analysis
• density functional theory studies
• protein
• ligand
• antimalarial

Acknowledgments

The authors thank the college management for encouragement and permission to carry out this work and PG and Research Department of Physics, N.M.S.S.V.N. College, Nagamalai, Madurai-19 for providing the Gaussian 09 program package. The SAIF IIT, Chennai shall be duly acknowledged for recording the FT-IR, UV and FT-Raman spectra.

Disclosure statement

No potential conflict of interest was reported by the author(s).