DFT study on the adsorption of 5-fluorouracil on B40, B39M, and M@B40 (M = Mg, Al, Si, Mn, Cu, Zn)

Design, synthesis, and computational studies of novel imidazo[1,2-a]pyrimidine derivatives as potential dual inhibitors of hACE2 and spike protein for blocking SARS-CoV-2 cell entry

In the present work, a new series of imidazo[1,2-a]pyrimidine Schiff base derivatives have been obtained using an easy and conventional synthetic route. The synthesized compounds were spectroscopically characterized using ¹H, ¹³C NMR, LC-MS(ESI), and FT-IR techniques. Green metric calculations indicate adherence to several green chemistry principles. The energy of Frontier Molecular Orbitals (FMO), Molecular Electrostatic Potential (MEP), Quantum Theory of Atoms in Molecules (QTAIM), and Reduced Density Gradient (RDG) were determined by the Density Functional Theory (DFT) method at B3LYP/6-31 G (d, p) as the basis set. Moreover, molecular docking studies targeting the human ACE2 and the spike, key entrance proteins of the severe acute respiratory syndrome coronavirus-2 were carried out along with hACE2 natural ligand Angiotensin II, the MLN-4760 inhibitor as well as the Cannabidiolic Acid CBDA which has been demonstrated to bind to the spike protein and block cell entry. The molecular modeling results showed auspicious results in terms of binding affinity as the top-scoring compound exhibited a remarkable affinity (-9.1 and -7.3 kcal/mol) to the ACE2 and spike protein respectively compared to CBDA (-5.7 kcal/mol), the MLN-4760 inhibitor (-7.3 kcal/mol), and angiotensin II (-9.2 kcal/mol). These findings suggest that the synthesized compounds may potentially act as effective entrance inhibitors, preventing the SARS-CoV-2 infection of human cells. Furthermore, in silico, ADMET, and drug-likeness prediction expressed promising drug-like characteristics.

Interaction of 5-Fluorouracil on the Surfaces of Pristine and Functionalized Ca12O12 Nanocages: An Intuition from DFT

The utilization of nanostructured materials for several biomedical applications has tremendously increased over the last few decades owing to their nanosizes, porosity, large surface area, sensitivity, and efficiency as drug delivery systems. Thus, the incorporation of functionalized and pristine nanostructures for cancer therapy offers substantial prospects to curb the persistent problems of ineffective drug administration and delivery to target sites. The potential of pristine (Ca₁₂O₁₂) and formyl (-CHO)- and amino (-NH₂)-functionalized (Ca₁₂O₁₂-CHO and Ca₁₂O₁₂-NH₂) derivatives as efficient nanocarriers for 5-fluorouracil (5FU) was studied at the B3LYP-GD3(BJ)/6-311++G(d,p) theoretical level in two electronic media (gas and solvent). To effectively account for all adsorption interactions of the drug on the investigated surfaces, electronic studies as well as topological analysis based on the quantum theory of atoms in molecules (QTAIM) and noncovalent interactions were exhaustively utilized. Interestingly, the obtained results divulged that the 5FU drug interacted favorably with both Ca₁₂O₁₂ and its functionalized derivatives. The adsorption energies of pristine and functionalized nanostructures were calculated to be -133.4, -96.9, and -175.6 kcal/mol, respectively, for Ca₁₂O₁₂, Ca₁₂O₁₂-CHO, and Ca₁₂O₁₂-NH2. Also, both topological analysis and NBO stabilization analysis revealed the presence of interactions among O₃-H₃₂, O₂₇-C₂₄, O₁₀-C₂₇, and N₂₄-H₃₂ atoms of the drug and the surface. However, 5FU@Ca₁₂O₁₂-CHO molecules portrayed the least adsorption energy due to considerable destabilization of the molecular complex as revealed by the computed deformation energy. Therefore, 5FU@Ca₁₂O₁₂ and 5FU@Ca₁₂O₁₂-NH₂ acted as better nanovehicles for 5FU.

DFT study of adsorbing SO2, NO2, and NH3 gases based on pristine and carbon-doped Al24N24 nanocages

The adsorption of SO₂, NO₂, and NH₃ toxic gases on Al₂₄N₂₄ and Al₂₄N₂₃C nanocages was investigated by using density functional theory (DFT) calculations. The adsorption energies, frontier orbitals, charge transfer using natural bonding orbital (NBO) analysis, dipole moment, the partial density of states (PDOS), thermodynamic relationships, non-covalent interaction (NCI), and quantum theory of atoms in molecules (QTAIM) were considered. The results reveal that carbon-doped Al₂₄N₂₄ nanocage increases the adsorption energies for SO₂ and NO₂ gases while decreasing the adsorption energy of NH₃ gas. The ΔG for all configurations were negative except the configurations A1 and G2 confirming the weak adsorption of these two complexes. In conclusion, Al₂₄N₂₄ and Al₂₄N₂₃C nanocages are in general promising adsorbents for the removal of SO₂, NO₂, and NH₃ toxic gases. The Al₂₄N₂₄ and Al₂₄N₂₃C nanocages are ideal electronic materials.