New 4-thiazolidinone/quinoline-2-ones scaffold: Design, synthesis, docking studies and biological evaluation as potential urease inhibitors

Stereoselective synthesis and X-ray structure determination of novel 1,2-dihydroquinolinehydrazonopropanoate derivatives

A novel series of 1,2-dihydroquinolinhydrazonopropanoate have been synthesized via a convenient aza-Michael addition reaction between hydrazinylquinolinones and ethyl propiolate in ethanol under refluxing temperature. The structures for all obtained products were confirmed with FTIR, NMR spectrums, as well as mass spectrometry. In addition, the monoclinic structure for compounds 8a, 8c, and 8d was also confirmed via X-ray crystallography analyses. The E-configuration for the obtained products was confirmed form the X-ray analysis. On the other hand, the crystal packing shows that the intermolecular and hydrogen bonds between atoms are parallel to the bc plan.

An overview of the privileged synthetic heterocycles as urease enzyme inhibitors: Structure-activity relationship

Urease is a metalloenzyme including two Ni2+ ions, found in some plants, bacteria, fungi, microorganisms, invertebrate animals, and animal tissues. Urease acts as a significant virulence factor, mainly in catheter blockage and infective urolithiasis as well as in the pathogenesis of gastric infection. Therefore, studies on urease lead to novel synthetic inhibitors. In this review, the synthesis and antiurease activities of a collection of privileged synthetic heterocycles such as (thio)barbiturate, (thio)urea, dihydropyrimidine, and triazol derivatives were described and discussed according to structure-activity relationship findings in search of the best moieties and substituents that are answerable for encouraging the desired activity even more potent than the standard. It was found that linking substituted phenyl and benzyl rings to the heterocycles led to potent urease inhibitors.

Evaluation of synthetic aminoquinoline derivatives as urease inhibitors: in vitro, in silico and kinetic studies

Background: Quinoline and acyl thiourea scaffolds have major chemical significance in medicinal chemistry. Quinoline-based acyl thiourea derivatives may potentially target the urease enzyme. Materials & methods: Quinoline-based acyl thiourea derivatives 1-26 were synthesized and tested for urease inhibitory activity. Results: 19 derivatives (1-19) showed enhanced urease enzyme inhibitory potential (IC50 = 1.19-18.92 μM) compared with standard thiourea (IC50 = 19.53 ± 0.032 μM), whereas compounds 20-26 were inactive. Compounds with OCH3, OC2H5, Br and CH3 on the aryl ring showed significantly greater inhibitory potential than compounds with hydrocarbon chains of varying length. Molecular docking studies were conducted to investigate ligand interactions with the enzyme's active site. Conclusion: The identified hits can serve as potential leads against the drug target urease in advanced studies.

Novel quinoline/thiazinan-4-one hybrids; design, synthesis, and molecular docking studies as potential anti-bacterial candidates against MRSA

In an attempt to develop effective and safe antibacterial agents, we synthesized novel thiazinanones by combining the quinolone scaffold and the 1,3-thiazinan-4-one group by reaction between ((4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)methylene)hydrazinecarbothioamides and 2,3-diphenylcycloprop-2-enone in refluxing ethanol in the presence of triethyl amine as a catalyst. The structure of the synthesized compounds was characterized by spectral data and elemental analysis, IR, MS, ¹H and ¹³C NMR spectroscopy which showed two doublet signals for CH-5 and CH-6 and four sharp singlets for the protons of thiazinane NH, CH[double bond, length as m-dash]N, quinolone NH and OH, respectively. Also, the ¹³C NMR spectrum clearly showed the presence of two quaternary carbon atoms which were assigned to thiazinanone-C-5 and C-6. All the 1,3-thiazinan-4-one/quinolone hybrids were screened for antibacterial activity. Compounds 7a, 7e and 7g showed broad spectrum antibacterial activity against most of the tested strains either G +ve or G -ve. Compound 7e is the most potent antibacterial agent against MRSA with the minimum inhibitory concentration against MRSA found to be 48 μg mL^-1 compared to the drug ciprofloxacin (96 μg mL^-1). Additionally, a molecular docking study was performed to understand the molecular interaction and binding mode of the compounds on the active site of S. aureus Murb protein. In silico docking assisted data strongly correlated with the experimental approach of antibacterial activity against MRSA.

New bis-thiazolidinone based chalcone analogues as effective inhibitors of Alzheimer's disease: Synthesis, molecular docking, acetylcholinesterase and butyrylcholinesterase study

A series of twenty bis -thiazolidinone based chalcone scaffolds (1-20) were synthesized and characterized by using various spectroscopic tools such as HR-EI-MS, 1 HNMR, 13 CNMR and were screened in vitro for their AChE and BuChE inhibition profile. It was noteworthy, that all the synthetic analogues (except analogues 10, 12 and 1 4 , which are found to be inactive) showed moderate to good inhibitory potentials on screening against AchE and BuChE enzymes with IC 50 values ranging from 0.10 ±0.050 to 7.60 ± 0.10 µM and 0.10 ± 0.050µM to 10.70 ± 0.20 µM as compared to standard Donepezil inhibitor (IC 50 = 0.016 ± 0.12 µM), (IC 50 = 4.5 ± 0.11 µM).  Among the current series, analogue 20 (IC 50 = 0.10 ± 0.050µM), (IC 50 = 0.10 ± 0.050µM) bearing trihydroxy substitutions on ortho -, meta - and para -position of both rings A and B , respectively was found to be the most active inhibitor of AChE and BuChE enzymes . Analogue 19 (IC 50 = 0.20 ± 0.050 µM), (IC 50 = 0.20 ± 0.050µM) bearing dihydroxy substitutions on ortho - and meta -position of both ring A and ring B respectively, was identified as the second most potent inhibitor against both these enzymes. Potent analogs were further subjected to molecular docking study to identify the binding interactions with enzymes active site. SAR study was done for all the analogues mostly based on substitution pattern on both ring A and B respectively.

The Bioactivity of Thiazolidin-4-Ones: A Short Review of the Most Recent Studies

Thiazolidin-4-ones is an important heterocyclic ring system of a pharmacophore and a privileged scaffold in medicinal chemistry. This review is focused on the latest scientific reports regarding biological activities of thiazolidin-4-ones published in 2020 and 2021. The review covers recent information about antioxidant, anticancer, anti-inflammatory, analgesic, anticonvulsant, antidiabetic, antiparasitic, antimicrobial, antitubercular and antiviral properties of thiazolidin-4-ones. Additionally, the influence of different substituents in molecules on their biological activity was discussed in this paper. Thus, this study may help to optimize the structure of thiazolidin-4-one derivatives as more efficient drug agents. Presented information may be used as a practical hint for rational design of new small molecules with biological activity, especially among thiazolidin-4-ones.