Charge-transfer chemistry of two corticosteroids used adjunctively to treat COVID-19. Part II: The CT reaction of hydrocortisone and dexamethasone donors with TCNQ and fluoranil acceptors in five organic solvents

Moamen S Refat; Bander Albogami; Abdel Majid A Adam; Hosam A Saad; Amnah Mohammed Alsuhaibani; Lal Miyan; Mohamed S Hegab

doi:10.1016/j.molliq.2022.119878

Charge-transfer chemistry of two corticosteroids used adjunctively to treat COVID-19. Part II: The CT reaction of hydrocortisone and dexamethasone donors with TCNQ and fluoranil acceptors in five organic solvents

J Mol Liq. 2022 Oct 1:363:119878. doi: 10.1016/j.molliq.2022.119878. Epub 2022 Jul 21.

Authors

Moamen S Refat¹, Bander Albogami², Abdel Majid A Adam¹, Hosam A Saad¹, Amnah Mohammed Alsuhaibani³, Lal Miyan⁴, Mohamed S Hegab⁵

Affiliations

¹ Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
² Department of Biology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
³ Department of Physical Sport Science, College of Education, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
⁴ Department of Chemistry, Faculty of Science, Aligarh Muslim University, Aligarh 202002(UP), India.
⁵ Deanship of Supportive Studies (D.S.S.), Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.

Abstract

Hydrocortisone (termed as D1) and dexamethasone (termed as D2) are corticosteroids currently used to treat COVID-19. COVID-19 is a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Exploring additional chemical properties of drugs used in the treatment protocols for COVID-19 could help scientists alike improve these treatment protocols and potentially even the vaccines (i.e., Janssen, Moderna, AstraZeneca, Pfizer-BioNTech). In this work, the charge-transfer (CT) properties of these two corticosteroids (D1 and D2) with two universal acceptors: 7,8,8-tetracyanoquinodimethane (termed as TCNQ) and fluoranil (termed as TFQ) in five different solvents were investigated. The examined solvents were MeOH, EtOH, MeCN, CH₂Cl₂, and CHCl₃. The CT interactions formed stable corticosteroid CT complexes in all examined solvents. Several spectroscopic parameters were derived, and the oscillator strength (f) and transition dipole moment (μ_e.g. ) values revealed that the interaction between the investigated corticosteroids with TCNQ acceptor is much stronger than their interaction with TFQ acceptor. The CT interactions were proposed to process via n → π* transition.

Keywords: Charge-transfer interaction; Dexamethasone; Hydrocortisone; Organic solvents; TCNQ acceptor; TFQ acceptor.