Synthesis and biological evaluation of isatin derivatives containing 1,3,4-thiadiazole as potent a-glucosidase inhibitors

Advancing drug discovery: Thiadiazole derivatives as multifaceted agents in medicinal chemistry and pharmacology

In this dispensation of rapid scientific and technological advancements, significant efforts are being made to curb health-related diseases. Research discoveries have highlighted the value of heterocyclic compounds, particularly thiadiazole derivatives, due to their diverse pharmacological activities. These compounds play a crucial role in therapeutic medicine and the development of effective drugs. Thiadiazoles are five-membered heterocyclic compounds consisting of one sulfur and two nitrogen atoms. This review explores advanced synthesis techniques, including the use of heterogeneous catalysts, microwave-assisted methods, ultrasound-assisted synthesis, solvent-free processes, multicomponent reactions, copper-catalyzed aerobic oxidative annulation, intramolecular cyclization, click-chemistry supported synthesis, and alkali-promoted, transition-metal-free mediated synthesis. These methods enhance the diversity and potential applications of thiadiazole compounds. Furthermore, this study provides up-to-date information on the key pharmacological activities of thiadiazole derivatives, highlighting their potential in therapeutic medicine for drug development. The structure-activity relationship (SAR) is also discussed to better understand their interactions and safety in biological systems. This work aims to expand on the reported chemistry and pharmacological potential of the thiadiazole moiety to validate their efficacy as promising pharmacophores in drug design and development.

Development and assessment of novel pyrazole-thiadiazol hybrid derivatives as VEGFR-2 inhibitors: design, synthesis, anticancer activity evaluation, molecular docking, and molecular dynamics simulation

Cancer remains a significant health challenge globally, requiring the development of targeted chemotherapeutics capable of specifically inhibiting cancer cell growth. Angiogenesis is one of the key features of tumor growth and metastasis and is, therefore, an important target for the treatment of many tumors. The vascular endothelial growth factor (VEGF) signaling pathway has proven to be a promising lead in anticancer therapy due to the central role it plays in tumor angiogenesis. Vascular endothelial growth factor receptor-2 (VEGFR-2) is a key mediator in the signaling pathway regulating angiogenesis. Targeting VEGFR-2 may disrupt angiogenesis, leading to a reduction in tumor blood supply and tumor progression. The design, synthesis, and assessment of novel VEGFR-2 inhibitor derivatives are the focus of this study, with particular emphasis on incorporating the pyrazole-thiadiazol pharmacophore into the molecular structure. Taking advantage of the pharmacophoric properties of pyrazole and 1,3,4-thiadiazol, compounds with different substituents in the main structure were designed and synthesized. The compounds were also evaluated for antiproliferative activity against cancer cell lines. Compound 4e demonstrated the highest activity among all compounds, with an IC50 of 9.673 ± 0.399 μM against HT-29 cells and 23.081 ± 0.400 μM against NIH3T3 cells. To further support the inhibitory activity of compound 4e, an in silico study was performed. Compound 4e demonstrated strong binding to the active site of VEGFR-2 in molecular docking studies, forming hydrogen bonds with key amino acid residues. The stability of the compound in the enzyme's active site was demonstrated through molecular dynamics simulations.

Thiazolidine-2,4-dione derivatives as potential α-glucosidase inhibitors: Synthesis, inhibitory activity, binding interaction and hypoglycemic activity

In order to find effective α-glucosidase inhibitors, a series of thiazolidine-2,4-dione derivatives (C1 ∼ 36) were synthesized and evaluated for α-glucosidase inhibitory activity. Compared to positive control acarbose (IC50 = 654.35 ± 65.81 μM), all compounds (C1 ∼ 36) showed stronger α-glucosidase inhibitory activity with IC50 values of 0.52 ± 0.06 ∼ 9.31 ± 0.96 μM. Among them, C23 with the best anti-α-glucosidase activity was a reversible mixed-type inhibitor. Fluorescence quenching suggested the binding process of C23 with α-glucosidase in a static process. Fluorescence quenching, CD spectra, and 3D fluorescence spectra results also implied that the binding of C23 with α-glucosidase caused the conformational change of α-glucosidase to inhibit the activity. Molecular docking displayed the binding interaction of C23 with α-glucosidase. Compound C23 (8 ∼ 64 μM) showed no cytotoxicity against LO2 and 293 cells. Moreover, oral administration of C23 (50 mg/kg) could reduce blood glucose and improve glucose tolerance in mice.

Synthesis of 1,2,3-triazole-1,3,4-thiadiazole hybrids as novel α-glucosidase inhibitors by in situ azidation/click assembly

α-Glucosidase inhibition is widely used in the oral management of diabetes mellitus (DM), a disease characterized by high blood sugar levels (hyperglycemia) and abnormal carbohydrate metabolism. In this respect, a series of 1,2,3-triazole-1,3,4-thiadiazole hybrids 7a-j were synthesized, inspired by a copper-catalyzed one-pot azidation/click assembly approach. All the synthesized hybrids were screened for inhibition of the α-glucosidase enzyme, displaying IC₅₀ values ranging from 63.35 ± 0.72 to 613.57 ± 1.98 μM, as compared to acarbose (reference) with IC₅₀ of 844.81 ± 0.53 μM. The hybrids 7h and 7e with 3-nitro and 4-methoxy substituents at the phenyl ring of the thiadiazole moiety were the best active hybrids of this series with IC₅₀ values of 63.35 ± 0.72 μM, and 67.61 ± 0.64 μM, respectively. Enzyme kinetics analysis of these compounds revealed a mixed mode of inhibition. Moreover, molecular docking studies were also performed to gain insights into the structure-activity-relationships of the potent compounds and their corresponding analogs.

Inhibition of α-glucosidase enzyme by 'click'-inspired pharmacophore framework 1,3,4-thiadiazole-1,2,3-triazole hybrids

Aim: α-Glucosidase inhibitors are important oral antidiabetic drugs that are used alone or in combination therapy. Materials & methods: In this regard, 1,3,4-thiadiazoles-1,2,3-triazoles were designed, synthesized and evaluated for α-glucosidase enzyme inhibition. Results: The applied synthesis protocol involved a 'click' reaction between a novel alkyne derived from a 1,3,4-thiadiazole derivative and phenylacetamide azides. The hybrid (9n) bearing 2-methyl and 4-nitro substituents was the best inhibitor with an IC₅₀ value of 31.91 μM (acarbose IC₅₀ = 844.81 μM). The blind molecular docking study of the best derivative (9n) showed that it interacted with the allosteric site's amino acid residues of α-glucosidase. Conclusion: 'Click'-inspired potential α-glucosidase inhibitors (1,3,4-thiadiazole-1,2,3-triazole hybrids) were identified and structure-activity relationship and kinetic and molecular docking studies accomplished.