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

Synthesis, Characterization, and antiviral evaluation of New Chalcone-Based Imidazo[1,2-a]pyridine Derivatives: Insights from in vitro and in silico Anti-HIV studies

Given the ease of synthetic accessibility and the promising biological profile demonstrated by both imidazo[1,2-a]pyridine and Chalcone derivatives, a series of Chalcone-based imidazo[1,2-a]pyridine derivatives were synthesized and characterized using 1H NMR, 13C NMR, Mass Spectrometry and FTIR techniques. Density functional theory (DFT) was employed to investigate the structural and electronic properties, providing insights into potential reactive sites. The synthesized compounds were evaluated in vitro for their antiviral properties against human immunodeficiency virus type-1 (HIV-1) and human immunodeficiency virus type-2 (HIV-2) in MT-4 cells. Furthermore, Molecular docking studies show strong binding affinities with HIV-1 reverse transcriptase and HIV-2 protease. To further understand the dynamic behavior and stability of these interactions, molecular dynamics (MD) simulations were conducted. The MD results indicated stable binding conformations of the ligands within the active sites, with low RMSD and RMSF values throughout the simulation, confirming the robustness of these interactions. ADME predictions suggested acceptable pharmacokinetic profiles, though solubility remains a limitation for these compounds. Although the in vitro antiviral activity was limited, the combination of in vitro and in silico approaches provided valuable insights, guiding further structural optimization to improve bioavailability and enhance the therapeutic potential of these derivatives.

Biological and computational assessments of thiazole derivative-reinforced bile salt enriched nano carriers: a new gate in targeting SARS-CoV-2 spike protein

There is merit in investigating novel therapeutic molecules that hit vital targets during the viral infection cycle i.e. disrupting the interaction between SARS-CoV-2's spike glycoprotein and the host's angiotensin converting enzyme 2 (ACE2) receptor, potentially offering new avenues for treatment. Accordingly, lipid-based vesicular systems like liposomes or niosomes are frequently utilized to overcome these hurdles. Thus, chemically synthesized compounds were encapsulated within PEGylated bilosomes (PBs) to improve their solubility and intestinal permeability, thereby enhancing their anti-SARS-CoV-2 effectiveness. The formulae were prepared according to 23 full factorial design which was also used to explore the impact of the change in predetermined formulation variables on the properties of the prepared vesicles (entrapment efficiency EE%, particle size PS, and zeta potential ZP). Additionally, the optimized formula (F4) which is composed of 3% bile salt (BS), 40 mg 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPE) and sodium deoxycholate (SDC) as a bile salt, was selected as an optimum formula with desirability value 0.674 using Design Expert® software. Both the in vitro release and ex vivo experiments results confirmed the significant superiority of the F4 over the drug dispersion. Both cytotoxicity and anti-SARS-CoV-2 activity of all examined compound-loaded PBs (PB3a-PB3g) were assessed in Vero E6 cells via MTT assay. Both compounds PB3c and PB3g displayed the highest IC50 values (0.71 and 1.25 μg mL-1, respectively) ensuring their superior antiviral potential. Moreover, it was revealed that PB3c demonstrated more than 80% virucidal activity and over 80% inhibition of viral adsorption with little effect on the viral replication ∼(5-10%). Moreover, molecular docking and dynamic studies were conducted to pursue the binding affinities of the investigated compounds towards the ACE2 target of the SARS-CoV-2 spike protein, assuring their feasible inhibitory potential. Collectively, the investigated compound-loaded PBs can be treated as promising lead drug delivery panels for COVID-19 management.

Synthesis, crystal structure, and antiviral evaluation of new imidazopyridine-schiff base derivatives: in vitro and in silico anti-HIV studies

A series of Imidazo[1,2-a]pyridine-Schiff base derivatives were synthesized and characterized using 1H NMR, 13C NMR, Mass Spectrometry and FTIR techniques, and the structure of 4a was further confirmed through single-crystal X-ray diffraction analysis. Density Functional Theory (DFT) has been used to investigate the structural and electronic properties. The synthesized compounds were evaluated in vitro for their antiviral activity against human immunodeficiency virus type-1 (HIV-1) and human immunodeficiency virus type-2 (HIV-2) in MT-4 cells. Compound 4a displayed EC50 values of 82,02 and 47,72 μg ml-1 against HIV-1 and HIV-2, respectively. Molecular docking studies were conducted to gain insights into the interaction mechanism of the synthesized compounds with HIV-1 reverse transcriptase. ADME analysis suggested acceptable pharmacokinetic profiles, though solubility remains a limitation for these compounds, highlighting the need for further structural modifications to enhance bioavailability and therapeutic potential.

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

The heterocyclic core of imidazo[1,2-a]pyrimidine was formed in satisfactory yields as a result of the interaction of the readily available 2-aminoimidazole with N-substituted maleimides or N-arylitaconimides. The mechanism of the studied processes was postulated basing on experimental data, HPLC-MS analysis of reaction mixtures, and quantum chemical calculations. Molecular docking results of the obtained imidazo[1,2-a]pyrimidines, when compared with voriconazole, a drug already in clinical use, suggest that they may possess antifungal activity against Candida albicans.

Design, Synthesis, Molecular Docking, and ADME-Tox Investigations of Imidazo[1,2-a]Pyrimidines Derivatives as Antimicrobial Agents

A convenient and effective synthesis of imidazo[1,2-a]pyrimidine derivatives has been developed under microwave irradiations using Al2O3 as a catalyst in solvent-free conditions. The functionalized imidazo[1,2-a]pyrimidine derivatives are useful in biochemistry and medical science. In our investigation, the antimicrobial activity of the synthesized compounds was evaluated against 13 microorganisms, including 6 Gram-positive bacteria, 4 Gram-negative bacteria, and 3 pathogenic fungi. Bioactivity tests revealed that the majority of the compounds exhibited good antimicrobial activity. Finally, molecular docking simulations and ADME-T predictions were performed, showing that the most active compounds have good binding modes with microbial targets and promising pharmacokinetic safety profiles.

Synthesis, Characterizations, and Quantum Chemical Investigations on Imidazo[1,2-a]pyrimidine-Schiff Base Derivative: (E)-2-Phenyl-N-(thiophen-2-ylmethylene)imidazo[1,2-a]pyrimidin-3-amine

In this study, (E)-2-phenyl-N-(thiophen-2-ylmethylene)imidazo[1,2-a]pyrimidin-3-amine (3) is synthesized, and detailed spectral characterizations using 1H NMR, 13C NMR, mass, and Fourier transform infrared (FT-IR) spectroscopy were performed. The optimized geometry was computed using the density functional theory method at the B3LYP/6-311++G(d,p) basis set. The theoretical FT-IR and NMR (1H and 13C) analysis are agreed to validate the structural assignment made for (3). Frontier molecular orbitals, molecular electrostatic potential, Mulliken atomic charge, electron localization function, localized orbital locator, natural bond orbital, nonlinear optical, Fukui functions, and quantum theory of atoms in molecules analyses are undertaken and meticulously interpreted, providing profound insights into the molecular nature and behaviors. In addition, ADMET and drug-likeness studies were carried out and investigated. Furthermore, molecular docking and molecular dynamics simulations have been studied, indicating that this is an ideal molecule to develop as a potential vascular endothelial growth factor receptor-2 inhibitor.

Current state-of-the-art and potential future therapeutic drugs against COVID-19

The novel coronavirus disease (COVID-19) continues to endanger human health, and its therapeutic drugs are under intensive research and development. Identifying the efficacy and toxicity of drugs in animal models is helpful for further screening of effective medications, which is also a prerequisite for drugs to enter clinical trials. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) invades host cells mainly by the S protein on its surface. After the SARS-CoV-2 RNA genome is injected into the cells, M protein will help assemble and release new viruses. RdRp is crucial for virus replication, assembly, and release of new virus particles. This review analyzes and discusses 26 anti-SARS-CoV-2 drugs based on their mechanism of action, effectiveness and safety in different animal models. We propose five drugs to be the most promising to enter the next stage of clinical trial research, thus providing a reference for future drug development.