Pyrazoline tethered 1,2,3-triazoles: Synthesis, antimicrobial evaluation and in silico studies

Density functional modeling, and molecular docking with SARS-CoV-2 spike protein (Wuhan) and omicron S protein (variant) studies of new heterocyclic compounds including a pyrazoline nucleus

Nowadays, different vaccines and antiviral drugs have been developed and their effectiveness has been proven against SARS-CoV-2. Pyrazoline derivatives are biologically active molecules and exhibit broad-spectrum biological activity properties. In this scope, four new molecules (4a-d) including a pyrazoline core were synthesized in order to predict their antiviral properties theoretically. Compounds 4a-d were purified by the crystallization method. The structures of 4a-d were completely characterized by NMR, IR, and elemental analysis. The molecular structures of the compounds in the ground state have been optimized using density functional theory with the B3LYP/6-31++G(d,p) level. The quantum chemical parameters were predicted by density functional theory calculations. Moreover, the molecular docking studies of 4a-d with SARS-CoV-2 Spike protein (Wuhan) and omicron S protein (variant) were presented to investigate and predict potential interactions. The binding sites, binding types and energies, bond distances of the non-covalent interactions and calculated inhibition constants (calc. Ki) as a consequence of molecular docking for 4a-d were presented in this study. Furthermore, the stability of the protein-4a complex obtained from the docking was investigated through molecular dynamics simulation.Communicated by Ramaswamy H. Sarma.

Synthesis, antimicrobial evaluation and docking studies of fluorinated imine linked 1,2,3-triazoles

A diverse series of imine linked 1,2,3-triazole hybrids has been synthesized via Cu(I)-promoted click reaction, with an aim to develop some new antimicrobial molecules. The structural characterization of the synthesized triazole hybrids was accomplished using various spectral techniques like ¹H NMR, ¹³C NMR, FTIR and HRMS. Among the synthesized hybrids, 7d exhibited highest antimicrobial efficacy against R. oryzae and S. aureus with MIC of 0.0123 µmol/mL and 0.0061 µmol/mL, respectively. Docking studies of the terminal alkynes (4a, 4b) and triazole hybrids (6a, 6d, 7c, 7g) showing high potency towards E. coli DNA gyrase and C. albicans sterol 14-α demethylase were also undertaken to understand the binding behaviour.

Synthesis and Evaluation of 1,3,5-Triaryl-2-Pyrazoline Derivatives as Potent Dual Inhibitors of Urease and α-Glucosidase Together with Their Cytotoxic, Molecular Modeling and Drug-Likeness Studies

In the present work, a concise library of 1,3,5-triaryl-2-pyrazolines (2a-2q) was designed and synthesized by employing a multistep strategy, and the newly synthesized compounds were screened for their urease and α-glucosidase inhibitory activities. The compounds (2a-2q) were characterized using a combination of several spectroscopic techniques including FT-IR, ¹H NMR, ¹³C NMR, and EI-MS. All the synthesized compounds, except compound 2i, were potent against urease as compared to the standard inhibitor thiourea (IC₅₀ = 21.37 ± 0.26 μM). These analogs disclosed varying degrees of urease inhibitory activities ranging from 9.13 ± 0.25 to 18.42 ± 0.42 μM. Compounds 2b, 2g, 2m, and 2q having IC₅₀ values of 9.36 ± 0.27, 9.13 ± 0.25, 9.18 ± 0.35, and 9.35 ± 0.35 μM, respectively, showed excellent inhibitory activity as compared to standard thiourea (IC₅₀ = 21.37 ± 0.26 μM). A kinetic study of compound 2g revealed that compound 2g inhibited urease in a competitive mode. Among the synthesized pyrazolines, the compounds 2c, 2k, 2m, and 2o exhibited excellent α-glucosidase inhibitory activity with the lowest IC₅₀ values of 212.52 ± 1.31, 237.26 ± 1.28, 138.35 ± 1.32, and 114.57 ± 1.35 μM, respectively, as compared to the standard acarbose (IC₅₀ = 375.82 ± 1.76 μM). The compounds (2a-2q) showed α-glucosidase IC₅₀ values in the range of 114.57 ± 1.35 to 462.94 ± 1.23 μM. Structure-activity relationship revealed that the size and electron-donating or -withdrawing effects of substituents influenced the activities, which led to the urease and α-glucosidase inhibiting properties. Compound 2m was a dual potent inhibitor against urease and α-glucosidase due to the presence of 2-CF₃ electron-withdrawing functionality on the phenyl ring. To the best of our knowledge, these synthetic compounds were found to be the most potent dual inhibitors of urease and α-glucosidase with minimum IC₅₀ values. The cytotoxicity of the compounds (2a-2q) was also investigated against human cell lines MCF-7 and HeLa. Compound 2l showed moderate cytotoxic activity against MCF-7 and HeLa cell lines. Moreover, in silico studies on most active compounds were also performed to understand the binding interaction of most active compounds with active sites of urease and α-glucosidase enzymes. Some compounds exhibited drug-like characteristics due to their lower cytotoxic and good ADME profiles.

Urea-thiazole/benzothiazole hybrids with a triazole linker: synthesis, antimicrobial potential, pharmacokinetic profile and in silico mechanistic studies

Some urea-thiazole/benzothiazole hybrids with a triazole linker were synthesized via Cu(I)-catalysed click reaction. After successfully analysed by various spectral techniques including FTIR, NMR and HRMS, antimicrobial screening of the synthesized hybrids along with their precursors was carried out against two Gram (+) bacteria (Staphylococcus aureus and Bacillus endophyticus), two Gram (-) bacteria (Escherichia coli and Pseudomonas fluorescens) and two fungi (Candida albicans and Rhizopus oryzae). All the synthesized compounds (4a-4l) displayed better biological response than the standard fluconazole against both of the tested fungi. Compounds 4h and 4j were found to be the most active compounds against R. oryzae and C. albicans, respectively. Molecular docking of hybrid 4j and its alkyne precursor 1b in the active site of C. albicans target sterol 14-α demethylase was also performed and was also supported by molecular dynamics studies. In silico ADME prediction of synthesized urea-thiazole/benzothiazole hybrids with a triazole linker and their alkyne precursors was also predicted.