Novel hydrazono-2-iminothiazolidin-4-ones based on a monoterpenic skelton as potential antitumor agents: Synthesis, DFT studies, in vitro cytotoxicity, apoptosis inducing properties and molecular docking

A new series of analogs-2-imino-4-thiazolidinone hybrid derivatives were synthesized by treatment of limonaketone-thiosemicarbazone derivatives with ethyl bromoacetate and dimethyl acetylene dicarboxylate (DMAD) as the cyclizing reagents. The new derivatives were characterized by HRMS, 1 H NMR and 13 C NMR spectroscopy techniques and one of them is characterized by single crystal X-ray diffraction. The newly synthesized products were biologically evaluated in vitro for their cytotoxic activity against three cancer cell lines including fibrosarcoma (HT-1080), lung carcinoma (A549), and breast carcinoma (MCF-7). Data showed that compounds 9 and 10 were the most active against HT-1080 cancer cell lines with the IC 50 values of 15.85±1.75 and16.13±1.55µM, respectively. The possible mechanism of apoptosis induction by the derivatives was investigated using Annexin V staining, caspase-3/7 activity and cell cycle analysis. Compound 10 was highly induced apoptosis through caspase-3/7 activation and S-phase arrest in HT-1080, while compound 9 showed a moderate induction of apoptosis through G0/G1-phase arrest in the same cell line. The molecular docking showed that compounds 9 and 10 activated the caspase-3 by forming a stable protein-ligand complex. Besides, the presence of phenyl moiety in ligand 10 is responsible for the enhancement of the caspase-3 activation by the apparition of two additional hydrogen bonds with Cys163 and Gln161amino acids.

In Vivo and Ex Vivo Evaluation of 1,3-Thiazolidine-2,4-Dione Derivatives as Euglycemic Agents

Thiazolidinediones (TZDs), used to treat type 2 diabetes mellitus, act as full agonists of the peroxisome proliferator-activated receptor gamma. Unfortunately, they produce adverse effects, including weight gain, hepatic toxicity, and heart failure. Our group previously reported the design, synthesis, in silico evaluation, and acute oral toxicity test of two TZD derivatives, compounds 40 (C40) and 81 (C81), characterized as category 5 and 4, respectively, under the Globally Harmonized System. The aim of this study was to determine whether C40, C81, and a new compound, C4, act as euglycemic and antioxidant agents in male Wistar rats with streptozotocin-induced diabetes. The animals were randomly divided into six groups (n = 7): the control, those with diabetes and untreated, and those with diabetes and treated with pioglitazone, C40, C81, or C4 (daily for 21 days). At the end of the experiment, tissue samples were collected to quantify the level of glucose, insulin, triglycerides, total cholesterol, and liver enzymes, as well as enzymatic and nonenzymatic antioxidant activity. C4, without a hypoglycemic effect, displayed the best antioxidant activity. Whereas C81 could only attenuate the elevated level of blood glucose, C40 generated euglycemia by the end of the treatment. All compounds produced a significant decrease in triglycerides.

Design, synthesis and evaluation of benzothiazole derivatives as multifunctional agents

Oxidative stress is the product or aetiology of various multifactorial diseases; on the other hand, the development of multifunctional compounds is a recognized strategy for the control of complex diseases. To this end, a series of benzothiazole derivatives was synthesized and evaluated for their multifunctional effectiveness as antioxidant, sunscreen (filter), antifungal and antiproliferative agents. Compounds were easily synthesized via condensation reaction between 2-aminothiophenols and different benzaldehydes. SAR study, particularly in position 2 and 6 of benzothiazoles, led to the identification of 4g and 4k as very interesting potential compounds for the design of multifunctional drugs. In particular, compound 4g is the best blocker of hERG potassium channels expressed in HEK 293 cells exhibiting 60.32% inhibition with IC₅₀ = 4.79 μM.

Saturated Five-Membered Thiazolidines and Their Derivatives: From Synthesis to Biological Applications

In past decades, interdisciplinary research has been of great interest for scholars. Thiazolidine motifs behave as a bridge between organic synthesis and medicinal chemistry and compel researchers to explore new drug candidates. Thiazolidine motifs are very intriguing heterocyclic five-membered moieties present in diverse natural and bioactive compounds having sulfur at the first position and nitrogen at the third position. The presence of sulfur enhances their pharmacological properties, and, therefore, they are used as vehicles in the synthesis of valuable organic combinations. They show varied biological properties viz. anticancer, anticonvulsant, antimicrobial, anti-inflammatory, neuroprotective, antioxidant activity and so on. This diversity in the biological response makes it a highly prized moiety. Based on literature studies, various synthetic approaches like multicomponent reaction, click reaction, nano-catalysis and green chemistry have been employed to improve their selectivity, purity, product yield and pharmacokinetic activity. In this review article, we have summarized systematic approaches for the synthesis of thiazolidine and its derivatives, along with their pharmacological activity, including advantages of green synthesis, atom economy, cleaner reaction profile and catalyst recovery which will help scientists to probe and stimulate the study of these scaffolds.

Synthesis: Small library of hybrid scaffolds of benzothiazole having hydrazone and evaluation of their β-glucuronidase activity

Due to the great biological importance of β-glucuronidase inhibitors, here in this study, we have synthesized a library of novel benzothiazole derivatives (1-30), characterized by different spectroscopic methods and evaluated for β-glucuronidase inhibitory potential. Among the series sixteen compounds i.e.1-6, 8, 9, 11, 14, 15, 20-23 and 26 showed outstanding inhibitory potential with IC₅₀ value ranging in between 16.50 ± 0.26 and 59.45 ± 1.12 when compared with standard d-Saccharic acid 1,4-lactone (48.4 ± 1.25 µM). Except compound 8 and 23 all active analogs showed better potential than the standard. Structure activity relationship has been established.

Synthesis and Biological Evaluation of Novel Benzothiazole Derivatives as Potential Anticonvulsant Agents

New benztriazoles with a mercapto-triazole and other heterocycle substituents were synthesized and evaluated for their anticonvulsant activity and neurotoxicity by using the maximal electroshock (MES), subcutaneous pentylenetetrazole (scPTZ), and rotarod neurotoxicity (TOX) tests. Among the compounds studied, compound 2-((1H-1,2,4-triazol-3-yl)thio)-N-(6-((3-fluorobenzyl)oxy)benzo[d]thiazol-2-yl)acetamide (5i) and 2-((1H-1,2,4-triazol-3-yl)thio)-N-(6-((4-fluorobenzyl)oxy)benzo[d] thiazol-2-yl)acetmide (5j) were the most potent, with an ED₅₀ value of 50.8 mg/kg and 54.8 mg/kg in the MES test and 76.0 mg/kg and 52.8 mg/kg in the scPTZ seizures test, respectively. They also showed lower neurotoxicity and, therefore a higher protective index. In particular, compound 5j showed high protective index (PI) values of 8.96 in the MES test and 9.30 in the scPTZ test, which were better than those of the standard drugs used as positive controls in this study.