Synthesis, molecular modelling and biological significance of N-(4-(4-bromophenyl) thiazol-2-yl)-2-chloroacetamide derivatives as prospective antimicrobial and antiproliferative agents

Synthesis, biological evaluation and in silico studies of some new analogues of 3,5-vdisubstituted thiazolidin-2,4-dione

Background: A new series of 3,5-disubstituted thiazolidin-2,4-dione molecules were derived and characterized using various spectral techniques (1H NMR, IR, carbon, hydrogen, nitrogen, etc.) and physicochemical parameters. Materials & methods: The molecules were derived using Knoevenagel condensation followed by Mannich reaction and further synthesized analogues were screened for their antioxidant and antimicrobial potential using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging method and serial tube dilution method, respectively, along with in silico studies (docking and absorption, distribution, metabolism and excretion parameters) to explore the drug-receptor interaction and druglikeness. Results & conclusion: In antimicrobial screening, the analogs MP2, MM6, MM7 and MM8 displayed promising activity while molecule MM4 exhibited better antioxidant potential in the series. In molecular docking analysis, the best-fitted analogs, namely, MM6 and MM7, showed good interactions.

AI-Accelerated Design of Targeted Covalent Inhibitors for SARS-CoV-2

Direct-acting antivirals for the treatment of the COVID-19 pandemic caused by the SARS-CoV-2 virus are needed to complement vaccination efforts. Given the ongoing emergence of new variants, automated experimentation, and active learning based fast workflows for antiviral lead discovery remain critical to our ability to address the pandemic's evolution in a timely manner. While several such pipelines have been introduced to discover candidates with noncovalent interactions with the main protease (Mpro), here we developed a closed-loop artificial intelligence pipeline to design electrophilic warhead-based covalent candidates. This work introduces a deep learning-assisted automated computational workflow to introduce linkers and an electrophilic "warhead" to design covalent candidates and incorporates cutting-edge experimental techniques for validation. Using this process, promising candidates in the library were screened, and several potential hits were identified and tested experimentally using native mass spectrometry and fluorescence resonance energy transfer (FRET)-based screening assays. We identified four chloroacetamide-based covalent inhibitors of Mpro with micromolar affinities (KI of 5.27 μM) using our pipeline. Experimentally resolved binding modes for each compound were determined using room-temperature X-ray crystallography, which is consistent with the predicted poses. The induced conformational changes based on molecular dynamics simulations further suggest that the dynamics may be an important factor to further improve selectivity, thereby effectively lowering KI and reducing toxicity. These results demonstrate the utility of our modular and data-driven approach for potent and selective covalent inhibitor discovery and provide a platform to apply it to other emerging targets.

Synthesis, biological evaluation and in-silico ADME studies of novel series of thiazolidin-2,4-dione derivatives as antimicrobial, antioxidant and anticancer agents

Background

A novel series of thiazolidine-2,4-dione molecules was derived and their chemical structures were established using physiochemical parameters and spectral techniques (¹H-NMR, IR, MS etc.). The synthesized molecule were then evaluated for their antioxidant, anticancer and antimicrobial potential.

Results and discussion

Serial tube dilution method was employed to evaluate the antimicrobial potential against selected fungal and bacterial strains by taking fluconazole and cefadroxil as reference antifungal and antibacterial drugs respectively. 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity was used to assess the antioxidant potential of the synthesized analogues. Further, the anticancer potential of the selected molecules was assessed against DU-145 cancer cell lines using MTT assay. The drug-likeness was also evaluated by studying in-silico ADME parameters of the synthesized analogues.

Conclusion

In antioxidant evaluation studies, the analogue H5 with IC₅₀ = 14.85 μg/mL was found to be the most active molecule. The antimicrobial evaluation outcomes suggested that the molecules H5, H13, H15 and H18 possessed moderate to promising activity against the selected species of microbial strains having MIC range 7.3 µM to 26.3 µM. The results of anticancer evaluation revealed that all the screened derivatives possess mild anticancer potential. The in-silico ADME studies revealed that all the compounds were found to be drug-like.

Characterisation of twelve newly synthesised N-(substituted phenyl)-2-chloroacetamides with QSAR analysis and antimicrobial activity tests

In this study we screened twelve newly synthesised N-(substituted phenyl)-2-chloroacetamides for antimicrobial potential relying on quantitative structure-activity relationship (QSAR) analysis based on the available cheminformatics prediction models (Molinspiration, SwissADME, PreADMET, and PkcSM) and verified it through standard antimicrobial testing against Escherichia coli, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and Candida albicans. Our compounds met all the screening criteria of Lipinski’s rule of five (Ro5) as well as Veber’s and Egan’s methods for predicting biological activity. In antimicrobial activity tests, all chloroacetamides were effective against Gram-positive S. aureus and MRSA, less effective against the Gram-negative E. coli, and moderately effective against the yeast C. albicans. Our study confirmed that the biological activity of chloroacetamides varied with the position of substituents bound to the phenyl ring, which explains why some molecules were more effective against Gram-negative than Gram-positive bacteria or C. albicans. Bearing the halogenated p-substituted phenyl ring, N-(4-chlorophenyl), N-(4-fluorophenyl), and N-(3-bromophenyl) chloroacetamides were among the most active thanks to high lipophilicity, which allows them to pass rapidly through the phospholipid bilayer of the cell membrane. They are the most promising compounds for further investigation, particularly against Gram-positive bacteria and pathogenic yeasts.