Comparative Study of the Synthetic Approaches and Biological Activities of the Bioisosteres of 1,3,4-Oxadiazoles and 1,3,4-Thiadiazoles over the Past Decade

Exploring the Structural Attributes of Yoda1 for the Development of New-Generation Piezo1 Agonist Yaddle1 as a Vaccine Adjuvant Targeting Optimal T Cell Activation

Piezo1, a mechano-activated ion channel, has wide-ranging physiological and therapeutic implications, with the ongoing development of specific agonists unveiling cellular responses to mechanical stimuli. In our study, we systematically analyzed the chemical subunits in Piezo1 protein agonist Yoda1 to comprehend the structure-activity relationship and push forward next-generation agonist development. Preliminary screening assays for Piezo1 agonism were performed using the Piezo1-mCherry-transfected HEK293A cell line, keeping Yoda1 as a positive control. We introduce a novel Piezo1 agonist Yaddle1 (34, 0.40 μM), featuring a trifluoromethyl group, with further exploration through in vitro studies and density functional theory calculations, emphasizing its tetrel interactions, to act as an ambidextrous wedge between the domains of Piezo1. In contrast to the poor solubility of the established agonist Yoda1, our results showed that the kinetic solubility of Yaddle1 (26.72 ± 1.8 μM at pH 7.4) is 10-fold better than that of Yoda1 (1.22 ± 0.11 μM at pH 7.4). Yaddle1 (34) induces Ca2+ influx in human CD4+ T cell, suggesting its potential as a vaccine adjuvant for enhanced T cell activation.

Design, synthesis and biological evaluation of novel morpholinopyrimidine-5-carbonitrile derivatives as dual PI3K/mTOR inhibitors

In this study, novel morpholinopyrimidine-5-carbonitriles were designed and synthesized as dual PI3K/mTOR inhibitors and apoptosis inducers. The integration of a heterocycle at position 2, with or without spacers, of the new key intermediate 2-hydrazinyl-6-morpholinopyrimidine-5-carbonitrile (5) yielded compounds 6-10, 11a-c and 12a-h. The National Cancer Institute (USA) tested all compounds for antiproliferative activity. Schiff bases, 12a-h analogs, were the most active ones. The most promising compounds 12b and 12d exhibited excellent antitumor activity against the leukemia SR cell line, which is the most sensitive cell line, with IC50 0.10 ± 0.01 and 0.09 ± 0.01 μM, respectively, along with significant effects on PI3Kα/PI3Kβ/PI3Kδ with IC50 values of 0.17 ± 0.01, 0.13 ± 0.01 and 0.76 ± 0.04 μM, respectively, for 12b and 1.27 ± 0.07, 3.20 ± 0.16 and 1.98 ± 0.11, respectively, for 12d compared to LY294002. Compared to Afinitor, these compounds inhibited mTOR with IC50 values of 0.83 ± 0.05 and 2.85 ± 0.17 μM, respectively. Annexin-V and propidium iodide (PI) double labeling showed that compounds 12b and 12d promote cytotoxic leukemia SR apoptosis. Compounds 12b and 12d also caused a G2/M cell cycle arrest in the leukaemia SR cell line. The findings of this study indicate that the highest effect was observed for 12b, which was supported by western blot and docking analysis.

Thiadiazole and Thiazole Derivatives as Potential Antimicrobial Agents

BACKGROUND

This review summarizes data on heterocyclic systems with thiadiazole and thiazole fragments in molecules as promising antimicrobial agents.

INTRODUCTION

Thiadiazole and thiazole backbones are the most favored and well-known heterocycles, a common and essential feature of various drugs. These scaffolds occupy a central position and are the main structural components of numerous drugs with a wide spectrum of action. These include antimicrobial, antituberculous, anti-inflammatory, analgesic, antiepileptic, antiviral, and anticancer agents.

METHOD

The research is based on bibliosemantic and analytical methods using bibliographic and abstract databases, as well as databases of chemical compounds.

RESULT

This review reports on thiadiazole and thiazole derivatives, which have important pharmacological properties. We are reviewing the structural modifications of various thiadiazole and thiazole derivatives, more specifically, the antimicrobial activity reported over the last years, as we have taken this as our main research area. 80 compounds were illustrated, and various derivatives containing hydrazone bridged thiazole and pyrrole rings, 2-pyridine and 4-pyridine substituted thiazole derivatives, compounds containing di-, tri- and tetrathiazole moieties, spiro-substituted 4- thiazolidinone-imidazoline-pyridines were analyzed. Derivatives of 5-heteroarylidene-2,4- thiazolidinediones, fluoroquinolone-thiadiazole hybrids, and others.

CONCLUSION

1,3,4-thiadiazoles and thiazoles are valuable resource for researchers engaged in rational drug design and development in this area.

Antimicrobial Potency and E. coli β-Carbonic Anhydrase Inhibition Efficacy of Phenazone-Based Molecules

In this investigation, 4-antipyrinecarboxaldhyde was reacted with methyl hydrazinecarbodithioate to afford the carbodithioate derivative 3. The as-prepared carbodithioate derivative 3 is considered to be a key molecule for the preparation of new antipyrine-1,3,4-thiadiazole-based molecules (4-9) through its reaction with the appropriate hydrazonoyl halides. Furthermore, a typical Biginelli three-component cyclocondensation reaction involving ethyl acetoacetate, 4-antipyrinecarboxaldhyde, and thiourea under the standard conditions is carried out in the presence of sulfuric acid to afford the corresponding antipyrine-pyrimidine hybrid molecule (10). The latter was submitted to react with hydrazine monohydrate to provide the corresponding hydrazide derivative (11) which, under reaction with ethyl acetoacetate in refluxing ethanol containing catalytic amount of acetic acid, afforded the corresponding derivative (12). The structure of the newly synthesized compounds was affirmed by their spectral and microanalytical data. We also screened for their antimicrobial potential (ZOI and MIC) and conducted a kinetic study. Additionally, the mechanism of biological action was assessed by a membrane leakage assay and SEM imaging technique. Moreover, the biological activities and the binding modes of these compounds were further supplemented by an in silico docking study against E. coli β-carbonic anhydrase. The amount of cellular protein released by E. coli is directly correlated to the concentration of compound 9, which was found to be 177.99 µg/mL following treatment with 1.0 mg/mL of compound 9. This finding supports compound 9's antibacterial properties and explains how the formation of holes in the E. coli cell membrane results in the release of proteins from the cytoplasm. The newly synthesized compounds represent acceptable antimicrobial activities with potential action against E. coli β-carbonic anhydrase. The docking studies and antimicrobial activity test proved that compound (9) declared a greater activity than the other synthesized compounds.

Synthesis and Anticancer Evaluation of 4-Chloro-2-((5-aryl-1,3,4-oxadiazol-2-yl)amino)phenol Analogues: An Insight into Experimental and Theoretical Studies

We report herein the synthesis, docking studies and biological evaluation of a series of new 4-chloro-2-((5-aryl-1,3,4-oxadiazol-2-yl)amino)phenol analogues (6a-h). The new compounds were designed based on the oxadiazole-linked aryl core of tubulin inhibitors of IMC-038525 and IMC-094332, prepared in five steps and further characterized via spectral analyses. The anticancer activity of the compounds was assessed against several cancer cell lines belonging to nine different panels as per National Cancer Institute (NCI US) protocol. 4-Chloro-2-((5-(3,4,5-trimethoxyphenyl)-1,3,4-oxadiazol-2-yl)amino)phenol (6h) demonstrated significant anticancer activity against SNB-19 (PGI = 65.12), NCI-H460 (PGI = 55.61), and SNB-75 (PGI = 54.68) at 10 µM. The compounds were subjected to molecular docking studies against the active site of the tubulin-combretastatin A4 complex (PDB ID: 5LYJ); they displayed efficient binding and ligand 4h (with docking score = -8.030 kcal/mol) lay within the hydrophobic cavity surrounded by important residues Leu252, Ala250, Leu248, Leu242, Cys241, Val238, Ile318, Ala317, and Ala316. Furthermore, the antibacterial activity of some of the compounds was found to be promising. 4-Chloro-2-((5-(4-nitrophenyl)-1,3,4-oxadiazol-2-yl)amino)phenol (6c) displayed the most promising antibacterial activity against both Gram-negative as well as Gram-positive bacteria with MICs of 8 µg/mL and a zone of inhibition ranging from 17.0 ± 0.40 to 17.0 ± 0.15 mm at 200 µg/mL; however, the standard drug ciprofloxacin exhibited antibacterial activity with MIC values of 4 µg/mL.

New 5-Aryl-1,3,4-Thiadiazole-Based Anticancer Agents: Design, Synthesis, In Vitro Biological Evaluation and In Vivo Radioactive Tracing Studies

A new series of 5-(4-chlorophenyl)-1,3,4-thiadiazole-based compounds featuring pyridinium (3), substituted piperazines (4a-g), benzyl piperidine (4i), and aryl aminothiazoles (5a-e) heterocycles were synthesized. Evaluation of the cytotoxicity potential of the new compounds against MCF-7 and HepG2 cancer cell lines indicated that compounds 4e and 4i displayed the highest activity toward the tested cancer cells. A selectivity study demonstrated the high selective cytotoxicity of 4e and 4i towards cancerous cells over normal mammalian Vero cells. Cell cycle analysis revealed that treatment with either compound 4e or 4i induced cell cycle arrest at the S and G2/M phases in HepG2 and MCF-7 cells, respectively. Moreover, the significant increase in the Bax/Bcl-2 ratio and caspase 9 levels in HepG2 and MCF-7 cells treated with either 4e or 4i indicated that their cytotoxic effect is attributed to the ability to induce apoptotic cell death. Finally, an in vivo radioactive tracing study of compound 4i proved its targeting ability to sarcoma cells in a tumor-bearing mice model.