Thiohydantoins as Potential Antioxidant Agents: In vitro and in silico evaluation

DMF-DMA catalyzed Synthesis, molecular docking, in-vitro, in-silico design, and binding free energy studies of novel thiohydantoin derivatives as antioxidant and antiproliferative agents targeting EGFR tyrosine kinase and aromatase cytochrome P450 enzyme

A set of novels 2-thiohydantoin derivatives were synthesized and enaminone function was discussed at position 5 using DMFDMA catalyst which result in formation of pyrazole, isoxazole, benzoxazepine by using reagents such as hydrazine, hydroxylamine and 2-aminothiophenol. These newly synthesized compounds were evaluated for their antioxidant and antiproliferative activity. In vitro studies on the effect of 2-thiohydantoin on scavenging 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) confirmed the free radical scavenging and antioxidant activity of 2-thiohydantoin. The synthesized compounds show significant antioxidant activity. The in vitro antitumor activity of 2-thiohydantoin on MCF7 (breast) and PC3 cells (prostate) was evaluated using MTT assay. Some of the synthesized compounds show significant to moderate antiproliferative properties compared to reference drug erlotinib. Among all, compound 4a exhibit potent antitumor properties against MCF7 and PC3 cancer cell lines with IC50 = 2.53 ± 0.09 /ml & with IC50 = 3.25 ± 0.12 µg/ml respectively and has potent antioxidant activity with IC50 = 10.04 ± 0.49 µg/ml.

Antidiabetic Potential of Novel 1,3,5-Trisubstituted-2-Thioxoimidazloidin-4-One Analogues: Insights into α-Glucosidase, α-Amylase, and Antioxidant Activities

As the ninth leading cause of death globally, diabetes mellitus (DM) is considered to be the worst chronic metabolic disease requiring an enormous need for healthcare with over 578 million expected cases by 2023. Several recent findings have demonstrated that mediating the activity of carbohydrate-hydrolyzing enzymes, including α-amylase and α-glucosidase, could be a potential strategy for managing the development of DM. In the presented study, a novel set of 1,3,5-trisubstituted-2-thioxoimidazolidin-4-ones was designed, synthesized, and characterized. The antidiabetic activity of the synthesized compounds was explored by assessing their inhibitory activity toward α-amylase and α-glucosidase enzymes. The results demonstrated that this class of compounds exhibits considerable inhibitory activity toward both α-amylase and α-glucosidase enzymes. Among the synthesized compounds, compound 5a demonstrated the most inhibitory activity with IC₅₀ of 5.08 and µg/mL and 0.21 µg/mL toward α-glucosidase and α-amylase activities, respectively, as compared to the drug Acarbose (IC₅₀ = 5.76 µg/mL and 0.39 µg/mL, respectively). To gain insights into the antidiabetic potential of compound 5a, we assessed the cytotoxic and antioxidant activities. Our findings indicated that compound 5a displays considerable cytotoxicity toward WI-38 cells with an IC₅₀ of 88.54 µg/mL, as compared to the drug Celecoxib (IC₅₀ = 93.05 µg/mL). Further, compound 5a exhibited a high scavenging activity toward 2,2-Diphenyl1-picrylhydrazyl (DPPH) free radicals (IC₅₀ = 51.75 µg/mL) and showed a low potential to produce ROS as indicated by the monitoring of the generated H₂O₂ (132.4 pg/mL), as compared to Trolox (IC₅₀ = 58.09 µg/mL) and Celecoxib (171.6 pg/mL). Finally, we performed extensive molecular modeling studies to affirm the binding affinity of this class of compounds to the binding pocket of α-amylase and α-glucosidase enzymes. Collectively, our findings indicate that this class of compounds, particularly compound 5a, could be utilized as a lead structure for the development of novel compounds with potential antidiabetic and antioxidant activities.

Novel imidazolium-thiohydantoin hybrids and their Mn(iii) complexes for antimicrobial and anti-liver cancer applications

We present the effective synthesis and structural characterization of three novel imidazolium-thiohydantoin ligands (IMTHs, 5a–c) and their Mn(iii) complexes (Mn(iii)IMTHs, 6a–c) in this study. The findings of elemental analyses, spectral analyses and magnetic measurements will be used to infer the stoichiometry, coordination styles, and geometrical aspects of Mn(iii)IMTHs. The new compounds were evaluated for their chemotherapeutic potential against ESKAPE pathogens and liver cancer (HepG2). According to the MIC and MBC values, the bactericidal and bacteriostatic activities of IMTHs have been significantly improved following coordination with the Mn(iii) ion. The MTT assay results showed that all Mn(iii)IMTHs had the potential to reduce the viability of liver carcinoma (HepG2) cells in a dose-dependent manner, with the BF₄-supported complex (6b) outperforming its counterparts (6a and 6c) as well as a clinical anticancer drug (VBL). Additionally, Mn-IMTH₂ (6b) showed the highest level of selectivity (SI = 32.05) for targeting malignant cells (HepG2) over healthy cells (HL7702).

We present the effective synthesis and structural characterization of three novel imidazolium-thiohydantoin ligands (IMTHs, 5a–c) and their Mn(iii) complexes (Mn(iii)IMTHs, 6a–c) in this study.

Thiohydantoins and hydantoins derived from amino acids as potent urease inhibitors: Inhibitory activity and ligand-target interactions

We report the investigation of hydantoins and thiohydantoins derived from L and d-amino acids as inhibitors against the Canavalia ensiformis urease (CEU). The biochemical in vitro assay against CEU revealed a promising inhibitory potential for most thiohydantoins with six of them showing %I higher than the reference inhibitor thiourea (56.5%). In addition, thiohydantoin derived from l-valine, 1b, as well as the hydantoin 2d, derived from l-methionine, were identified as the most potent inhibitors with %I = 90.5 and 85.9 respectively. Enzyme kinetic studies demonstrated a mixed and uncompetitive inhibition profile for these compounds with K_i values of 0.42 mM for 1b and 0.99 mM for 2d. These kinetic parameters, obtained from traditional colorimetric assay, were strictly related to the K_D values measured spectroscopically by the Saturation Transfer Difference (STD) technique for the urease complex. STD was also used to evince the moieties of the ligands responsible for the binding with the enzyme. Molecular docking studies showed that the thiohydantoin and hydantoin rings can act as a pharmacophoric group due to their binding affinity by hydrogen bonding interactions with critical amino acid residues in the enzyme active and/or allosteric site. These findings agreed with the experimental alpha values, demonstrating that 1b has affinity by free enzyme, and 2d derivative, an uncompetitive inhibitor, has great binding affinity at the allosteric site. The results for the thiohydantoin 1a, derived from d-valine, demonstrated a drastic stereochemical influence on inhibition, kinetics, and binding parameters in comparison to its enantiomer 1b.