Spectroscopic Characterization, Quantum Chemical and Molecular Docking Studies on 1-Chloroanthraquinone: A Novel Oral Squamous Cell Carcinoma Drug

Abstract

Anthraquinone derivatives are well recognized for their anticancer activities and pharmacological properties. In the present study, comprehensive theoretical and experimental FT-IR, FT-Raman, and UV-visible spectroscopic studies on the 1-Chloroanthraquinone (CAQ) molecule were carried out. The optimized molecular structure and harmonic vibrational frequencies was calculated using Gaussian 09 program. The experimental and calculated vibrational wavenumbers were assigned, which correlated well with the previous literature. The UV-visible absorption spectrum of the CAQ molecule was computed in the liquid phase (ethanol), which exhibits n–π* electronic transition, and the results were compared with the observed UV-visible spectrum. From the frontier molecular orbital analysis, the calculated energy gap value (4.03 eV) indicates that the CAQ molecule has a stable structure and the value was comparable with the band gap energy value of the reported bioactive molecules. The electron back donation from the carbonyl group oxygen atom to the benzene ring was identified using Mulliken atomic charge distribution analysis. Molecular electrostatic potential surface analysis confirms the reactive sites of the molecule. The natural bond orbital analysis validates electron back donation from the carbonyl group oxygen atom to the benzene ring of the CAQ molecule. The molecular docking analysis results that the CAQ molecule acts as a good inhibitor of histone deacetylase 6 (HDAC6) protein. HDAC6 protein is associated with oral squamous cell carcinoma. Thus, the present study paves the way for designing novel drugs for the treatment of oral squamous cell carcinoma.

Keywords:

• 1-Chloroanthraquinone
• DFT
• FT-IR
• FT-Raman
• molecular docking
• oral squamous cell carcinoma drug

Acknowledgements

The authors thank the college management for encouragement and permission to carry out this work and also thank the P.G. 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, FT-Raman and UV-Vis spectra.

CRediT author statement

1. T. Valarmathi: Experimental characterization and Theoretical calculations, Writing- Original draft preparation

2. R. Premkumar: Molecular Docking analysis, Result analysis, Writing- Original draft preparation.

3. E. James Jebaseelan Samuel: Conceptualization, Theoretical result analysis and Reviewing.

4. A. Milton Franklin Benial: Result analysis, Supervision, Writing- Reviewing and Editing.

Disclosure statement

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