Synthesis, molecular docking and comparative efficacy of various alkyl/aryl thioureas as antibacterial, antifungal and α-amylase inhibitors

Exploring Acyl Thiotriazinoindole Based Pharmacophores: Design, Synthesis, and SAR Studies with Molecular Docking and Biological Activity Profiling against Urease, α-amylase, α-glucosidase, Antimicrobial, and Antioxidant Targets

A diminutive chemical library of acyl thiotriazinoindole (ATTI) based bioactive scaffolds was synthesized, instigated by taking the economical starting material Isatin, through a series of five steps. Isatin was first nitrated followed by the attachment of pentyl moiety via nucleophilic substitution reaction. The obtained compound was reacted with thiosemicarbazide to obtain thiosemicarbazone derivative, which was eventually cyclized using basic conditions in water as solvent. Finally, the reported series was obtained through reaction of nitrated thiotriazinoindole moiety with differently substituted phenacyl bromides. The synthesized compounds were characterized using NMR spectroscopy and elemental analysis. Finally, the synthesized motifs were scrutinized for their potential to impede urease, α-glucosidase, DPPH, and α-amylase. Compound 5 h with para cyano group manifested the most pivotal biological activity among all, displaying IC50 values of 29.7 ± 0.8, 20.5 ± 0.5 and 36.8 ± 3.9 µM against urease, α-glucosidase, and DPPH assay, respectively. Simultaneously, for α-amylase compound 5 g possessing a p-CH3 at phenyl ring unfolded as most active, with calculated IC50 values 90.3 ± 1.1 µM. The scaffolds were additionally gauged for their antifungal and antibacterial activity. Among the tested strains, 5d having bromo as substituent exhibited the most potent antibacterial activity, while it also demonstrated the highest potency against Aspergillus fumigatus. Other derivatives 5b, 5e, 5i, and 5j also exhibited dual inhibition against both antibacterial and antifungal strains. The interaction pattern of derivatives clearly displayed their SAR, and their docking scores were correlated with their IC50 values. In molecular docking studies, the importance of interactions like hydrogen bonding was further asserted. The electronic factors of various substituents engendered variety of interactions between the ligands and targets implying their importance in the structures of the synthesized heterocyclic scaffolds. To conclude, the synthesized compounds had satisfactory biological activity against various important targets. Further studies are therefore encouraged by attachment of different substitutions in the structure at various positions to enhance the activity of these compounds.

Novel pyrazoline linked acyl thiourea pharmacophores as antimicrobial, urease, amylase and α-glucosidase inhibitors: design, synthesis, SAR and molecular docking studies

In the present work, a small library of novel pyrazolinyl-acyl thiourea (5a-j) was designed and synthesized through a multistep sequence and the synthesized compounds were screened for their antifungal, antibacterial and antioxidant activities as well as urease, amylase and α-glucosidase inhibitory activities. The synthesized series (5a-o) was characterized using a combination of spectroscopic techniques, including FT-IR, 1H NMR and 13C NMR. All compounds (5a-j) were found to have significant potency against urease, α-glucosidase, α-amylase, and DPPH. The synthesized compounds were also screened for potential antibacterial and anti-fungal inhibition activities. IC50 values for all the prepared compounds for urease, α-glucosidase, amylase, and DPPH inhibition were determined and derivatives 5b and 5g were found to be the most potent urease inhibitors with IC50 values of 54.2 ± 0.32 and 43.6 ± 0.25 μM, respectively. Whilst compound 5b (IC50 = 68.3 ± 0.11 μM) is a potent α-glucosidase inhibitor, compound 5f (90.3 ± 1.08 μM) is a potent amylase inhibitor and compound 5b (103.4 ± 1.15 μM) is a potent antioxidant. The different substitutions on the phenyl ring were the basis for structure-activity relationship (SAR) study. The molecular docking study was performed for the confirmation of binding interactions.

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.

Synthesis of amantadine clubbed N-aryl amino thiazoles as potent urease, α-amylase & α-glucosidase inhibitors, kinetic and molecular docking studies

A series of ten novel compounds were synthesized by incorporating a 1,3 thiazole core into amantadine and their structures were validated using different analytical and spectral methods such as FTIR, EI-MS, 1H NMR, and 13C NMR. The antibacterial and enzyme inhibitory properties of these newly synthesized compounds were evaluated. Remarkably, the compounds exhibited significant antibacterial activity against Escherichia coli and Bacillus subtilis. Additionally, the in vitro inhibitory activities of the synthesized compounds, against α-amylase, α-glucosidase, and urease were investigated. Among the tested compounds, compound 6d demonstrated potent and selective inhibition of α-amylase IC50 = 97.37 ± 1.52 μM, while acarbose was used as positive control and exhibited IC50 = 5.17 ± 0.25 μM. Compound 6d and 6e exhibited prominent inhibition against α-glucosidase IC50 = 38.73 ± 0.80 μM and 41.63 ± 0.26 μM respectively. Furthermore, compound 6d inhibited urease with exceptional efficacy IC50 = 32.76 μM, while positive control thiourea showed more prominent activity having IC50 = 1.334 μM. Molecular docking studies disclosed the binding mechanism and affinity of these new inhibitors within the binding sites of various amino acids. To investigate the association between molecular structural characteristics and inhibitory actions of synthesized derivatives, preliminary structure-activity relationship (SAR) studies were performed. These findings indicated that compounds 6a, 6c, 6d and 6e are potential candidates for hit-to-lead follow-up in the drug-discovery process for treating diabetes and hyperglycemia.

Recent trends in chemistry, structure, and various applications of 1-acyl-3-substituted thioureas: a detailed review

The interest in acyl thioureas has continually been escalating owing to their extensive applications in diverse fields, such as synthetic precursors of new heterocycles, pharmacological and materials science, and technology. These scaffolds exhibit a wide variety of biological activities such as antitumor, enzyme inhibitory, anti-bacterial, anti-fungal, and anti-malarial activities and find utilization as chemosensors, adhesives, flame retardants, thermal stabilizers, antioxidants, polymers and organocatalysts. In addition, the synthesis, and applications of coordination complexes of these ligands have also been overviewed. The current review is a continuation of our previous efforts in this area, focusing on the recent advancements during the period 2017 to present.

This review encapsulates the recently designed acyl thioureas, and their crystal structures, metal complexes and various applications from 2017 to present, including pharmacological aspects, chemosensing and heterogenous catalysis.

Novel benzoylthiourea derivatives had differential anti-inflammatory photodynamic therapy potentials on in vitro stimulated mammalian macrophages

Novel benzoylthioureas, N-((5-chloropyridin-2yl)carbamothioyl)benzamide, (HL¹), N-((2-chloropyridin-3yl)carbamothioyl)benzamide, (HL²), N-((5-bromopyridin-2yl)carbamothioyl)benzamide, (HL³) and N-(Naphthalene-1-yl(phenyl)carbamothioyl)benzamide, (HL⁴), were synthesized. Their characterizations were made by FT-IR,¹H NMR and ¹³C NMR spectrophotometric analysis. Single crystal X-ray diffraction measurements were conducted to determine the crystal structure of HL¹ and HL⁴.  The HL¹ crystallization conditions are: in the monoclinic crystal system with P2₁/c space group, Z = 2, a = 8.118(2) Å, b = 12.056(3) Å, c = 13.753(4) Å. HL⁴crystallization conditions are: in the orthorhombic crystal system with Pbca space group, Z = 8, a = 19.597(9) Å, b = 8.270(4) Å, c = 24.299(11) Å. Investigation of photodynamic and antiinflamatory effects of these compounds revealed that they are potent adducts. Using these derivatives, mammalian macrophages were stimulated with LPS to test their anti-inflammatory activity. Based on pro-inflammatory cytokine production levels, the photodynamic anti-inflammatory activity of these adducts were found to differ. Our results showedthat benzoylthioureas can be used as potential photodynamic therapy agents to suppress the excessive inflammatory reactions encountered in autoimmune and inflammatory disorders.

Vibrational spectroscopy, quantum computational and molecular docking studies on 2-chloroquinoline-3-carboxaldehyde

The quantum mechanical density functional theory (DFT) approach was used to analyze vibrational spectroscopy for the title compound 2-chloroquinoline-3-carboxaldehyde, and the observations were compared to experimental results. B3LYP with the 6-311++ G (d, p) basis set produces the optimized molecular structure and vibrational assignments. The charge delocalization and hyper conjugative interactions were studied using NBO analysis. Fukui functions were used to determine the chemical reactivity of the examined molecule. The linear polarizability, first order polarizability, NLO and Thermodynamic properties are calculated. Additionally, Molecular electrostatic potential (MEP) and HOMO-LUMO are reported. Multi wavefunction analysis like ELF (Electron Localization Function) and LOL (Localized Orbital Locator) are analyzed. For the headline compound, drug-likeness properties were examined. Molecular docking analysis on the examined molecule are done to understand the biological functions of the headline molecule and the minimum binding energy, hydrogen bond interactions, are analyzed.

Synthesis and Characterization of New Fluoro/Trifluoromethyl-Substituted Acylthiourea Derivatives with Promising Activity against Planktonic and Biofilm-Embedded Microbial Cells

The aim of this study was preparation of new derivatives based on 2-((4-chlorophenoxy)methyl)-N-(arylcarbamothioyl)benzamide structure; the new compounds were characterized by IR, NMR (1H, 13C) spectroscopy, and elemental analysis. The obtained compounds were evaluated for their in vitro antimicrobial activity against planktonic and biofilm-embedded microbial cells (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans), by qualitative and quantitative assays. Some of the compounds revealed promising antibacterial and antifungal activities, with low minimum inhibitory concentration values between 0.15 and 2.5 mg/mL and minimal biofilm eradication concentrations of 0.019–2.5 mg/mL. To investigate the potential target of their antibacterial activity, in silico drug-likeness and molecular docking screenings on Staphylococcus aureus DNA gyrase were performed. The compound with the best antibacterial activity (1g) was docked into topoisomerase II DNA gyrase enzymes (PDB ID: 2XCS) and showed valuable interactions with the target protein along with good docking scores, suggesting that it can act by the inhibition of DNA replication. The tested compounds exhibited only a poor antioxidant activity, as revealed by the in vitro assay using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay.

Investigation on the effect of alkyl chain linked mono-thioureas as Jack bean urease inhibitors, SAR, pharmacokinetics ADMET parameters and molecular docking studies

The increasing resistance of pathogens to common antibiotics, as well as the need to control urease activity to improve the yield of soil nitrogen fertilization in agricultural applications, has stimulated the development of novel classes of molecules that target urease as an enzyme. In this context, the newly developed compounds on the basis of 1-heptanoyl-3-arylthiourea family were evaluated for Jack bean urease enzyme inhibition activity to validate their role as potent inhibitors of this enzyme. 1-Heptanoyl-3-arylthioureas were obtained in excellent yield and characterized through spectral and elemental analysis. All the compounds displayed remarkable potency against urease inhibition as compared to thiourea standard. It was found that novel compounds fulfill the criteria of drug-likeness by obeying Lipinski's rule of five. Particularly compound 4a and 4c can serve as lead molecules in 4D (drug designing discovery and development). Kinetic mechanism and molecular docking studies also carried out to delineate the mode of inhibition and binding affinity of the molecules.