Copper(II) Inhibition of the SARS-CoV-2 Main Protease

Single Crystal Investigations, Hirshfeld Surface Analysis, DFT Studies, Molecular Docking, Physico-Chemical Characterization, and Biological Activity of a Novel Non-Centrosymmetric Compound with a Copper Transition Metal Precursor

A novel organic-inorganic hybrid non-centrosymmetric superconductor material [2-ethylpiperazine tetrachlorocuprate(II)] has been synthesized and investigated by means of Fourier transform infrared spectroscopy, single-crystal X-ray crystallography, thermal analyses, and density functional theory (DFT) studies. The single-crystal X-ray analysis indicates that the studied compound crystallizes in the P2₁2₁2₁ orthorhombic space group. Hirshfeld surface analyses have been used to investigate non-covalent interactions. Organic cations [C₆H₁₆N₂]²⁺ and inorganic moieties [CuCl₄]^2- alternatively connect N-H···Cl and C-H···Cl hydrogen bonds. In addition, the energies of the frontier orbitals, highest occupied molecular orbital, lowest unoccupied molecular orbital, the reduced density gradient analyses and quantum theory of atoms in molecules analyses, and the natural bonding orbital are also studied. Furthermore, the optical absorption and photoluminescence properties were also explored. However, time-dependent/DFT computations were utilized to examine the photoluminescence and UV-vis absorption characteristics. Two different methods, 2, 2-diphenyl-1-picryhydrazyl radical and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid radical scavenging, were used to evaluate the antioxidant activity of the studied material. Furthermore, the title material was docked to the SARS-CoV-2 variant (B.1.1.529) in silico to study the non-covalent interaction of the cuprate(II) complex with active amino acids in the spike protein.

Can iron, zinc, copper and selenium status be a prognostic determinant in COVID-19 patients?

In severe COVID-19, the levels of iron (Fe), copper (Cu), zinc (Zn) and selenium (Se), do not only regulate host immune responses, but modify the viral genome, as well. While low serum Fe concentration is an independent risk factor for the increased death rate, Zn controls oxidative stress, synthesis of inflammatory cytokines and viral replication. Therefore, Zn deficiency associates with a worse prognosis. Although Cu exposure inactivates the viral genome and exhibits spike protein dispersal, increase in Cu/Zn due to high serum Cu levels, are correlated with enhanced risk of infections. Se levels are significantly higher in surviving COVID-19 patients. Meanwhile, both Zn and Se suppress the replication of SARS-CoV-2. Since the balance between the deficiency and oversupply of these metals due to a reciprocal relationship, has decisive effect on the prognosis of the SARS-CoV-2 infection, monitoring their concentrations may facilitate improved outcomes for patients suffering from COVID-19.

Structural Basis of Potential Inhibitors Targeting SARS-CoV-2 Main Protease

The Coronavirus disease-19 (COVID-19) pandemic is still devastating the world causing significant social, economic, and political chaos. Corresponding to the absence of globally approved antiviral drugs for treatment and vaccines for controlling the pandemic, the number of cases and/or mortalities are still rising. Current patient management relies on supportive treatment and the use of repurposed drugs as an indispensable option. Of a crucial role in the viral life cycle, ongoing studies are looking for potential inhibitors to the main protease (Mpro) of severe acute respiratory syndrome Coronavirus -2 (SARS-CoV-2) to tackle the pandemic. Although promising results have been achieved in searching for drugs inhibiting the Mpro, work remains to be done on designing structure-based improved drugs. This review discusses the structural basis of potential inhibitors targeting SARS-CoV-2 Mpro, identifies gaps, and provides future directions. Further, compounds with potential Mpro based antiviral activity are highlighted.