Synthesis and in vitro urease inhibitory activity of 5-nitrofuran-2-yl-thiadiazole linked to different cyclohexyl-2-(phenylamino)acetamides, in silico and kinetic studies

Discovery of bis-chalcones and bis-pyrimidines as potential urease inhibitors: from synthesis to computational insights

AIMS

This study focuses on the design and evaluation of bis-chalcones and bis-pyrimidines as potential urease inhibitors.

MATERIALS AND METHODS

A series of bis-chalcone and bis-pyrimidine derivatives were synthesized and assessed for their in vitro urease inhibitory activity. Kinetic studies were conducted using Lineweaver-Burk plots to determine the inhibition mechanism of the most potent compound. Molecular docking was employed to investigate the binding interactions with the urease active site, followed by MD simulations to validate complex stability. Computational ADMET analysis was performed to assess the drug-like properties of the most active inhibitor.

RESULTS

Several synthesized compounds exhibited potent urease inhibitory activity, significantly surpassing the standard inhibitor thiourea. The most active compound, 8P, displayed noncompetitive inhibition, as confirmed by kinetic studies. SAR analysis revealed that electron-withdrawing substituents enhanced inhibitory potency. Molecular docking studies demonstrated favorable interactions between inhibitors and key urease residues, while MD simulations confirmed complex stability. ADMET analysis supported the drug-like potential of 8P.

CONCLUSIONS

This study provides valuable insights into the development of target compounds as promising urease inhibitors. These findings suggest their potential therapeutic applications for urease-related disorders.

Design, synthesis, and in-Silco ADME prediction of some novel bis(1,3,4-thiadiazoles) encapsulated lipid-chitosan nano capsule decorative with magnetic nanoparticles and their potential anti-helicobacter pylori activity

Helicobacter pylori (H. pylori) is an extremely prevalent human pathogen globally that leads to severe illnesses. Sadly, the worldwide issue of H. pylori's resistance to antimicrobial medications persists. In this context, creating an anti-H. pylori vaccine that can deliver a satisfactory eradication rate with fewer side effects would be highly beneficial. In this regard, a new series of bis(1,3,4-thiadiazoles) was synthesized and assessed for antimicrobial activity against H. pylori. Combining two bioactive 1,3,4-thiadiazole portions within a single molecule to create a new bis-heterocycle represents an efficient strategy to produce powerful compounds and address issues of resistance and effectiveness. Every synthesized compound showed outstanding inhibition results. Compounds 5c and 8 exhibited the lowest MIC values, recorded at 7.5 and 15.6 μg/mL, respectively. Theoretical predictions were employed to evaluate ADME, leading to outcomes of low solubility, stability, and bioavailability. The effective agents aimed at H. pylori were encapsulated in an appropriate newly developed nanocarrier to tackle challenges related to low bioavailability and stability. Further tests were carried out to evaluate the efficacy of antimicrobials against H. pylori, resulting in promising results. Additionally, the MIC values decreased by 4 and 2 times relative to their original synthetic versions. The activity of the enzyme urease was assessed before nanoencapsulation, showing an IC50 value of 8.99 μg/mL, which was reduced to 7.8 μg/mL after nanoencapsulation.

The Most Up-to-Date Advancements in the Design and Development of Urease Inhibitors (January 2020-March 2024)

The aim of this review is to address the most up-to-date information on the design and development, structure-activity relationship (SAR), and molecular docking study of novel and effective urease inhibitors between January 2020 and March 2024. Herein, the importance of the substituents and their effect on bioactivity of the reported compounds have been investigated. Besides, the relation between the most important residues inside the active site of the urease enzyme for interactions of the inhibitors and the active site of the enzyme has also been reviewed. This review has been classified into main reported scaffolds, namely, barbiturates, thiobarbiturates, Schiff bases, semicarbazides, thiosemcarbazides, benzimidazoles, 1,3,4-thiadiazoles, and 1,3,4-oxadiazoles, to provide better insight into the newly developed urease inhibitors.

Design, synthesis, and biological studies of the new cysteine-N-arylacetamide derivatives as a potent urease inhibitor

Inhibition of Helicobacter pylori urease is an effective method in the treatment of several gastrointestinal diseases in humans. This bacterium plays an important role in the pathogenesis of gastritis and peptic ulceration. Considering the presence of cysteine and N-arylacetamide derivatives in potent urease inhibitors, here, we designed hybrid derivatives of these pharmacophores. Therefore, cysteine-N-arylacetamide derivatives 5a-l were synthesized through simple nucleophilic reactions with good yield. In vitro urease inhibitory activity assay of these compounds demonstrated that all newly synthesized compounds exhibited high inhibitory activity (IC50 values = 0.35-5.83 μM) when compared with standard drugs (thiourea: IC50 = 21.1 ± 0.11 μM and hydroxyurea: IC50 = 100.0 ± 0.01 μM). Representatively, compound 5e with IC50 = 0.35 μM was 60 times more potent than strong urease inhibitor thiourea. Enzyme kinetic study of this compound revealed that compound 5e is a competitive urease inhibitor. Moreover, a docking study of compound 5e was performed to explore crucial interactions at the urease active site. This study revealed that compound 5e is capable to inhibit urease by interactions with two crucial residues at the active site: Ni and CME592. Furthermore, a molecular dynamics study confirmed the stability of the 5e-urease complex and Ni chelating properties of this compound. It should be considered that, in the following study, the focus was placed on jack bean urease instead of H. pylori urease, and this was acknowledged as a limitation.

Structure-based drug discovery and antimicrobial activity of ciprofloxacin-grafted Ugi adducts

A new series of ciprofloxacin-derived Ugi adducts were rationally designed and synthesized. The synthesized molecules were explored for their potential antimicrobial activities against four pathogenic microorganisms. Among these derivatives, compound 7h with a 4-nitrophenyl substituent at R2 exhibited significant activity against two tested Gram-positive bacteria with a minimum inhibitory concentration value of 0.097 µg/mL while 7i bearing 4-chlorophenyl pendant demonstrated the best antimicrobial activities against Gram-negative bacteria. Furthermore, the analysis of the structure-activity relationships disclosed that types of substitutions differently affect the bacteria so the most potent derivative against Gram-negative infections was the least active one in Gram-positive microorganisms. Also, the molecular docking and molecular dynamic simulations were executed on 7i as the most potent Gram-negative anti-bacterial agent against ATP-binding sites of DNA gyrase B. Accordingly, our findings suggest that ciprofloxacin-based Ugi adducts are an interesting precursor for the design of potent antimicrobial agents.Communicated by Ramaswamy H. Sarma.

[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives as new therapeutic candidates against urease positive microorganisms: design, synthesis, pharmacological evaluations, and in silico studies

Regarding the important role of the urease enzyme as a virulence factor in urease-positive microorganisms in this study, new series of [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives were designed and synthesized. All compounds evaluated against urease enzyme exhibiting IC50 values of 0.87 ± 0.09 to 8.32 ± 1.21 µM as compared with thiourea as the positive control (IC50 = 22.54 ± 2.34 µM). The kinetic evaluations of 6a as the most potent derivative recorded a competitive type of inhibition. Molecular dynamic simulations of the 6a derivative were also conducted, showing that 6a occupied the active site with closed state. Antimicrobial activities of all derivatives were performed, and 6f (R = 3-Cl), 6g (R = 4-Cl), and 6h (R = 3,4-diCl) analogs demonstrated significant antifungal activities with MIC values of 1, 2, and 0.5 µg/mL compared with fluconazole with MIC = 2 µg/mL. Synthesized analogs also exhibited potent urease inhibitory activities against C. neoformans (IC50 = 83.7-118.7 µg/mL) and P. mirabilis (IC50 = 74.5-113.7 µg/mL), confirming their urease inhibitory potential. The results demonstrated that the designed scaffold could be considered a suitable pharmacophore to develop potent urease inhibitors.

New thioxothiazolidinyl-acetamides derivatives as potent urease inhibitors: design, synthesis, in vitro inhibition, and molecular dynamic simulation

To identify potent urease inhibitors, in the current study, a series of thioxothiazolidinyl-acetamides were designed and synthesized. The prepared compounds were characterized by spectroscopic techniques, including FTIR, ¹HNMR, ¹³CNMR, and elemental analysis. In the enzymatic assessments, it was demonstrated that all derivatives had significant urease inhibition with IC₅₀ values in the range of 1.473-9.274 µM in comparison with the positive control hydroxyurea (IC₅₀ = 100.21 ± 2.5 µM) and thiourea (IC₅₀ = 23.62 ± 0.84 µM). Compound 6i (N-benzyl-3-butyl-4-oxo-2-thioxothiazolidine-5-carboxamide) was the most active agent with an IC₅₀ value of 1.473 µM. Additionally, kinetic investigation and in silico assessments of 6i was carried out to understand the type of inhibition and behavior of the most potent derivative within the binding site of the enzyme. Noteworthy, the anti-urease assay against P. vulgaris revealed 6e and 6i as the most active agents with IC₅₀ values of 15.27 ± 2.40 and 17.78 ± 3.75 µg/mL, respectively. Antimicrobial evaluations of all compounds reveal that compounds 6n and 6o were the most potent antimicrobial agents against the standard and resistant S. aureus. 6n and 6o also showed 37 and 27% inhibition in the development of biofilm by S. aureus at 512 µg/ml. Furthermore, the MTT test showed no toxicity up to 100 µM. Taken together, the study suggests that the synthesized thioxothiazolidinyl-acetamides bases derivatives may serve as potential hits as urease inhibitors.