5-Ene-4-thiazolidinones - An efficient tool in medicinal chemistry

Microwave-assisted protocol towards synthesis of heterocyclic molecules: a comparative analysis with conventional synthetic methodologies (years 2019-2023): a review

Microwave-assisted protocols have become extensively accepted across various scientific and technological domains because of their numerous advantages, shorter reaction times, higher yields, and often milder reaction conditions. In this review, we focus on the synthesis of N, O, and S-containing heterocyclic structural cores, crucial in the development of pharmaceuticals, agrochemicals, and materials science following through conventional and microwave method via eliminating the side products and enhances the product yield that is nowadays the biggest barrier for a synthetic chemist. The major findings emphasizes the substantial advantages of microwave-assisted techniques over conventional synthetic protocols. This comparative study underscores the potential of microwave-assisted techniques to revolutionize heterocyclic compound synthesis, providing insights into optimizing reaction conditions and expanding the scope of chemical synthesis in industrial applications.

Synthesis and in vitro antitrypanosomatid activity of novel 5-nitroindole-rhodanine conjugates

AIM

Trypanosomatid diseases, leishmaniasis and trypanosomiasis are vector-borne parasitic diseases that can cause death and catastrophic economic losses for millions of people. The growing resistance of trypanosomatid parasites to current treatments highlights the urgent need for new therapeutic agents. This study explored 5-nitroindole-rhodanine conjugates to identify promising new compounds with the potential for future development as antitrypanosomatid treatments.

MATERIALS AND METHODS

The conjugates were synthesized in a multi-step process and evaluated in vitro for antileishmanial activity against Leishmania (L.) donovani and L. major strains. Cytotoxicity was assessed on Vero and THP-1 cells. Due to the taxonomic relation to Trypanosoma spp. the compounds were also screened for in vitro activity against species that cause zoonotic trypanosomiasis.

RESULTS AND CONCLUSION

Several hits were found with leishmanicidal activity against both L. donovani and L. major strains. Of these, 3d was identified as a potential early lead that exhibited nanomolar cidal activity against L. major, and greater selectivity than the reference drug amphotericin B. However, the compounds did not have similar activity levels against Trypanosoma spp. Hence, these compounds should be further investigated for their mechanism of action and in vivo antileishmanial activity to determine their potential as a leishmaniasis treatment.

Synthesis, Biological Evaluation, and Molecular Docking Studies of Indole-Based Heterocyclic Scaffolds as Potential Antibacterial Agents

Indole-based heterocyclic scaffolds have become increasingly important in medicinal chemistry due to their notable pharmacological and biological properties. Their role in the discovery and development of innovative drugs for treating various diseases highlights their value. This study aimed to synthesize C3-indole derivatives linked to various heterocyclic scaffolds, including thiophenes, thiazolidine-4-ones, and 1,3,4-thiadiazoles, via the reaction of ethylthioacetanilide 2 with different α-haloketones.The structures of the target compounds were established using 1H and 13C nuclear magnetic resonance spectroscopy, mass spectrometry, infrared spectroscopy, and elemental analysis. The synthesized compounds were tested for antimicrobial activity against different microbes: S. aureus ATCC 6538 (Gram-positive bacteria), E. coli ATCC 25933 (Gram-negative bacteria), C. albicans ATCC 10231 (yeast), and fungi (A. niger NRRL-A326). Thiophene 6a, thiazolidine-4-one 8, and compound 10d exhibited the highest antimicrobial activities. The molecular docking study showed that compounds 2, 4, 6a, and 6c had good binding energy and favorable binding modes of interactions with the DNA gyrase B enzymes (PDB: 3 U2D) and (PDB: 1S14). The results showed that the NH group of the indole in compounds 2 and 4, together with the nitrile group (CN), played an important role in inhibiting DNA gyrase B of S. aureus, PDB: 3 U2D. Furthermore, the NH of the indole ring, together with the ethylamino group of compound 2, was crucial in inhibiting DNA gyrase B of E. coli, PDB: 1S14. These findings may encourage researchers to develop more effective C3-indole derivatives in their search for antimicrobial drugs.

Efficacy of thiazole derivatives against colorectal cancer induced by dimethylhydrazine in male Wistar rats

Identifying novel biological activities in hit compounds remains a significant challenge in cancer research. In this study, we evaluated the anticancer and safety profiles of two previously studied thiazole-based derivatives, Les-5303 and Les-6485, in a colorectal cancer (CRC) model induced by dimethylhydrazine (DMH) in male Wistar rats. CRC was induced through subcutaneous DMH administration at a 20 mg/kg dose for 20 weeks. Les-5303 and Les-6485 were then administered intrarectally at a 6 mg/kg dose for 5 days. The effects of these compounds on oxidative stress, the antioxidant system, inflammation, NO-synthase activity in the colonic mucosa and blood plasma, and hepatotoxicity markers, were thoroughly assessed. Both compounds demonstrated significant anticancer activity and antioxidant properties. Les-5303, however, exhibited increased hepatotoxicity, as evidenced by elevated AST activity and reduced urea concentration in the blood, indicating its potential for liver damage. In contrast, Les-6485 showed no significant hepatotoxic effects, maintaining normal hepatic enzyme activities and urea levels, suggesting a better safety profile. These findings highlight the distinct biological effects of Les-5303 and Les-6485, with Les-6485 showing promising anticancer activity coupled with minimal toxicity, making it a more favorable candidate for further development in CRC treatment.

Role of Ciminalum-4-thiazolidinone Hybrids in Molecular NF-κB Dependent Pathways

A range of hybrid molecules incorporating the ciminalum moiety in the thiazolidinone ring demonstrate significant anticancer and antimicrobial properties. Therefore, the aim of our study was to evaluate the properties and mechanism of action of two 4-thiazolidinone-based derivatives, i.e., 3-{5-[(Z,2Z)-2-chloro-3-(4-nitrophenyl)-2-propenylidene]-4-oxo-2-thioxothiazolidin-3-yl}propanoic acid (Les-45) and 5-[2-chloro-3-(4-nitrophenyl)-2-propenylidene]-2-(3-hydroxyphenylamino)thiazol-4(5H)-one (Les-247). In our study, we analyzed the impact of Les-45 and Les-247 on metabolic activity, caspase-3 activity, and the expression of genes and proteins related to inflammatory and antioxidant defenses and cytoskeleton rearrangement in healthy human fibroblasts (BJ) and a human lung carcinoma cell line (A549). The cells were exposed to increasing concentrations (1 nM to 100 μM) of the studied compounds for 24 h and 48 h. A decrease in the metabolic activity in the BJ and A549 cell lines was induced by both compounds at a concentration range from 10 to 100 µM. Both compounds decreased the mRNA expression of NRF2 (nuclear factor erythroid 2-related factor 2) and β-actin in the BJ cells. Interestingly, a significant decrease in the level of NF-κB gene and protein expression was detected in the BJ cell line, suggesting a direct impact of the studied compounds on the inhibition of inflammation. However, more studies are needed due to the ability of Les-45 and Les-247 to interfere with the tubulin/actin cytoskeleton, i.e., a critical system existing in eukaryotic cells.

Role of 4-Thiazolidinone-Pyrazoline/Indoline Hybrids Les-4369 and Les-3467 in BJ and A549 Cell Lines

Cancer is one of the most important problems of modern societies. Recently, studies have reported the anticancer properties of rosiglitazone related to its ability to bind peroxisome proliferator receptor γ (PPARγ), which has various effects on cancer and can inhibit cell proliferation. In this study, we investigated the effect of new 4-thiazolidinone (4-TZD) hybrids Les-4369 and Les-3467 and their effect on reactive oxygen species (ROS) production, metabolic activity, lactate dehydrogenase (LDH) release, caspase-3 activity, and gene and protein expression in human foreskin fibroblast (BJ) cells and lung adenocarcinoma (A549) cells. The ROS production and caspase-3 activity were mainly increased in the micromolar concentrations of the studied compounds in both cell lines. Les-3467 and Les-4369 increased the mRNA expression of PPARG, P53 (tumor protein P53), and ATM (ATM serine/threonine kinase) in the BJ cells, while the mRNA expression of these genes (except PPARG) was mainly decreased in the A549 cells treated with both of the tested compounds. Our results indicate a decrease in the protein expression of AhR, PPARγ, and PARP-1 in the BJ cells exposed to 1 µM Les-3467 and Les-4369. In the A549 cells, the protein expression of AhR, PPARγ, and PARP-1 increased in the treatment with 1 µM Les-3467 and Les-4369. We have also shown the PPARγ modulatory properties of Les-3467 and Les-4369. However, both compounds prove weak anticancer properties evidenced by their action at high concentrations and non-selective effects against BJ and A549 cells.

Copper-Catalyzed One-Pot Synthesis of Thiazolidin-2-imines

The synthesis of thiazolines, thiazolidines, and thiazolidinones has been extensively studied, due to their biological activity related to neurodegenerative diseases, such as Parkinson's and Alzheimer's, as well as their antiparasitic and antihypertensive properties. The closely related thiazolidin-2-imines have been studied less, and efficient strategies for synthesizing them, mainly based on the reaction of propargylamines with isothiocyanates, have been explored less. The use of one-pot approaches, providing modular, straightforward, and sustainable access to these compounds, has also received very little attention. Herein, we report a novel, one-pot, multicomponent, copper-catalyzed reaction among primary amines, ketones, terminal alkynes, and isothiocyanates, toward thiazolidin-2-imines bearing quaternary carbon centers on the five-membered ring, in good to excellent yields. Density functional theory calculations, combined with experimental mechanistic findings, suggest that the copper(I)-catalyzed reaction between the in situ-formed propargylamines and isothiocyanates proceeds with a lower energy barrier in the pathway leading to the S-cyclized product, compared to that of the N-cyclized one, toward the chemo- and regioselective formation of 5-exo-dig S-cyclized thiazolidin-2-imines.

Discovery of a new Bcl-2 inhibitor through synthesis, anticancer activity, docking and MD simulations

A database of 300 compounds was virtually screened and docked against Bcl-2 protein; the stability of the best-formed complex was evaluated through Molecular dynamics, the top ten compounds with the best in-silico complexation affinities were synthesized, and their In-vitro cytotoxic activity was examined. Thiazolidinone (4e) and isoxazoline (4a-d) were evaluated in-silico. For further evaluation and examination, we designed and synthesized from naturally occurring (R)-carvone and characterized it via spectroscopic analysis, as well as tested for their anticancer activities towards human cancer cell lines such as HT-1080 (fibrosarcome cancer), MCF-7 and MDA-MB-231 (breast cancer) and A-549 (lung cancer) by using MTT method with Doxorubicin as standard drug. Among them, compound 4d showed the most promising anticancer activity against HT-1080, A-549, MCF-7, and MDA-MB-231 cell lines with IC50 values of 15.59 ± 3.21 µM; 18.32 ± 2.73 µM; 17.28 ± 0.33 µM and 19.27 ± 2.73 µM respectively.Communicated by Ramaswamy H. Sarma.

Evaluation of novel synthesized thiazole derivatives as potential aromatase inhibitors against breast cancer

Background: 4-Methylacetophenone is used in the preparation of starting materials, 4-methylphenacyle bromide (2) and 4-methylacetophenone thiosemicarbazole (3). Results: Several novel 2,4-disubstituted-1,3-thiazole analogues were obtained via the treatment of starting materials with 4-methylphenacyl bromide, acetyl chloride, aromatic aldehydes and bromination providing thiazole derivatives 5-8 respectively. Conclusion: Compounds 5-8 were investigated for their cytotoxic activity on MCF-7 and normal breast cells. Active compounds were found and in contrast to staurosporine, compound 8 displayed the most potent cytotoxic action that showed a strong inhibitory effect (aromatase) and (protein tyrosine kinase) enzymes, proving that the novel thiazole derivatives promoted the effective anticancer drug candidates.

Green design and synthesis of some novel thiazolidinone appended benzothiazole-triazole hybrids as antimicrobial agents

The global increase in bacterial resistance poses a significant threat, jeopardizing the effectiveness of antibiotics. Therefore, the development of new and efficient antimicrobial agents is pre-dominant. Taking this into consideration, in the present study, we designed and reported the facile synthesis of two novel series benzothiazole-triazole and thiazolidinone-appended benzothiazole-triazole hybrids using a molecular hybridization approach in a one-pot process. The synthesized compounds were tested for microbial growth inhibition against bacterial and fungal strains. Among all the synthetics, compounds derived from methoxyphenyl and heteroaromatic ring substitutions exhibited promising inhibitory activity. The current investigation has emphasized that benzothiazole-triazole hybrids incorporating thiazolidinone can be a promising and potent category of molecules with potential biological activities. This sustainable and eco-friendly protocol involves the metal-free, catalyst-free synthesis of bioactive scaffolds, which merges broad tolerance for functional groups with a short reaction time, resulting in good to excellent yields.

Synthesis, Characterization, Antiglycation Evaluation, Molecular Docking, and ADMET Studies of 4-Thiazolidinone Derivatives

The design and development of new small-molecule glycation inhibitors are essential for preventing various chronic diseases, including diabetes mellitus, immunoinflammation, cardiovascular, and neurodegenerative diseases. 4-Thiazolidinone or thiazolidine-4-one is a well-known heterocyclic compound with the potential to inhibit the formation of advanced glycation end products. In the present work, we report the synthesis and characterization of four new 5-arylidene 3-cyclopropyl-2-(phenylimino)thiazolidin-4-one (1-4) compounds and their human serum albumin glycation inhibitory activity. One of the compounds 5-(2H-1,3-benzodioxol-5-ylmethylidene)-3-cyclopropyl-2-(phenylimino)-1,3-thiazolidin-4-one (3) showed potent inhibition in the synthesis of initial, intermediary, and final products of glycation reactions. Besides, conformational changes in the α-helix and β-sheet (due to hyperglycemia) were also found to be reversed upon the addition of (3). Experimental findings were complemented by computational [molecular docking, ADME/Tox, and density functional theory (DFT)] studies. The docking scores of the compounds were in order 1 > 3 > 2 > 4, indicating the importance of the polar group at the 5-arylidene moiety. The results of ADME/Tox and DFT calculations revealed the safe nature of the compounds with high drug-likeness and stability. Overall, we speculate that the results of this study could provide valuable insights into the biological activity of 4-thiazolidinones.

New 3-amino-2-thioxothiazolidin-4-one-based inhibitors of acetyl- and butyryl-cholinesterase: synthesis and activity

Aim: 2-Thioxothiazolidin-4-one represents a versatile scaffold in drug development. The authors used it to prepare new potent acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors that can be utilized, e.g., to treat Alzheimer's disease. Materials & methods: 3-Amino-2-thioxothiazolidin-4-one was modified at the amino group or active methylene, using substituted benzaldehydes. The derivatives were evaluated for inhibition of AChE and BChE (Ellman's method). Results & conclusion: The derivatives were obtained with yields of 52-94%. They showed dual inhibition with IC50 values from 13.15 μM; many compounds were superior to rivastigmine. The structure-activity relationship favors nitrobenzylidene and 3,5-dihalogenosalicylidene scaffolds. AChE was inhibited noncompetitively, whereas BChE was inhibited with a mixed type of inhibition. Molecular docking provided insights into molecular interactions. Each enzyme is inhibited by a different binding mode.

Thiazolidin-4-Ones as a Promising Scaffold in the Development of Antibiofilm Agents-A Review

Thiazolidin-4-ones have a broad range of medical and clinical implementation, which is important for pharmaceutical and medicinal chemistry. This heterocyclic core has been reported to possess a diversity of bioactivities, including antimicrobial and antibiofilm-forming potential. The resistance of biofilms to antibiotics or disinfectants is a serious medical problem. Therefore, there is a natural need to discover new effective structures with properties that inhibit biofilm formation. This review aims to analyze the antibiofilm features of thiazolidin-4-ones described in the literature over the last two decades. The information gathered in this review could benefit the rational design of new effective antibiofilm small molecules with thiazolidin-4-one cores.

In-vitro antiviral screening of some thiopyranothiazoles

Thiopyranothiazoles represent a promising class of drug-like molecules with broad pharmacological profiles. Some novel derivatives of isothiochromeno[4a,4-d]thiazole and chromeno[4',3':4,5]thiopyrano[2,3-d]thiazole were synthesized and screened against diverse viruses: coronavirus SARS, Influenza Viruses of type A and type B, Adeno- and Rhinovirus, Dengue Fever Virus, Respiratory Syncytial Virus, Rift Valley Fever Virus, Tacaribe Virus, Venezuelan Equine Encephalitis Virus, as well as Vaccinia and Human Cytomegalovirus. The antiviral activity assays revealed highly active isothiochromeno[4a,4-d]thiazole bearing phenazone fragment towards Influenza Virus type A (H1N1) with the selectivity index (SI) within 150. 5,8-Dihydro-2H-[1,3]thiazolo [5',4':5,6]thiopyrano [2,3-d][1,3]thiazol-2,6(3H)-diones showed moderate antiviral activity against influenza viruses and SARS-CoV. The obtained data indicate thiopyranothiazoles as promising class of fused 4-thiazolidinone derivatives possessing antiviral effects.

Development of new thiazolidine-2,4-dione hybrids as aldose reductase inhibitors endowed with antihyperglycaemic activity: design, synthesis, biological investigations, and in silico insights

This research study describes the development of new small molecules based on 2,4-thiazolidinedione (2,4-TZD) and their aldose reductase (AR) inhibitory activities. The synthesis of 17 new derivatives of 2,4-TZDs hybrids was feasible by incorporating two known bioactive scaffolds, benzothiazole heterocycle, and nitro phenacyl moiety. The most active hybrid (8b) was found to inhibit AR in a non-competitive manner (0.16 µM), as confirmed by kinetic studies and molecular docking simulations. Furthermore, the in vivo experiments demonstrated that compound 8b had a significant hypoglycaemic effect in mice with hyperglycaemia induced by streptozotocin. Fifty milligrams per kilogram dose of 8b produced a marked decrease in blood glucose concentration, and a lower dose of 5 mg/kg demonstrated a noticeable antihyperglycaemic effect. These outcomes suggested that compound 8b may be used as a promising therapeutic agent for the treatment of diabetic complications.

Rhodanine derivatives: An insight into the synthetic and medicinal perspectives as antimicrobial and antiviral agents

Rhodanine or 2-Thioxothiazolidin-4-one is a privileged heterocyclic compound offering a wide opportunity for structural modification, lead development, and modification. It is one of the highly decorated scaffolds in the drug discovery process. Rhodanine derivatives possess a plethora of biological activities due to their ability to interact with a diverse range of protein targets, which provide tremendous opportunities to discover new drugs with different modes of action. The most common strategy for developing novel rhodanine derivatives is the introduction of structurally diverse substituents at the C-5 or N-3, or both positions. Since the inception of Epralestat into the market in 1992, the exploration of rhodanine-3-acetic acids has led to the development of novel leads against different biological targets such as MRSA, HHV-6, Mycobacterial tuberculosis, dengue, etc. In the current pandemic era, some rhodanine compounds have been explored against SARS-CoV-2. In recent years, rhodanine and its derivatives have witnessed significant progress in developing new drug leads as potential antimicrobial and antiviral agents. Different synthetic methodologies and recent developments in the medicinal chemistry of rhodanine derivatives, including biological activities, their mechanistic aspects, structure-activity relationships, and in silico findings, have been compiled in the present review. This article will benefit the scientific community and offer perspectives on how these scaffolds as privileged structures might be exploited in the future for rational design and discovery of rhodanine-based bio-active molecules.

A comprehensive review on the antidiabetic attributes of thiazolidine-4-ones: Synthetic strategies and structure-activity relationships

The thiazolidine-4-one scaffold has recently emerged as a potential pharmacophore having clinical significance for medicinal chemists. This heterocyclic ring has been reported to possess a plethora of biological activities, including antidiabetic activity that has inspired researchers to integrate this core with different pharmacophoric fragments to design novel and effective antidiabetic leads. The antidiabetic activity has been observed due to the ability of the thiazolidine-4-one nucleus to interact with different biological targets, including peroxisome proliferator-activated receptor γ, protein tyrosine phosphatase 1B, aldose reductase, α-glucosidase, and α-amylase. The present review discusses the mode of action of thiazolidine-4-ones through these antidiabetic drug targets. This review attempts to summarize and analyze the recent developments with regard to the antidiabetic potential of thiazolidine-4-ones covering different synthetic strategies, structure-activity relationships, and docking studies reported in the literature. The significance of various structural modifications at C-2, N-3, and C-5 of the thiazolidine-4-one ring has also been discussed in this manuscript. This comprehensive compilation will provide an inevitable scope for the design and development of potential antidiabetic drug candidates having a thiazolidine-4-one core.

Small molecules containing chalcogen elements (S, Se, Te) as new warhead to fight neglected tropical diseases

Neglected tropical diseases (NTDs) encompass a group of infectious diseases with a protozoan etiology, high incidence, and prevalence in developing countries. As a result, economic factors constitute one of the main obstacles to their management. Endemic countries have high levels of poverty, deprivation and marginalization which affect patients and limit their access to proper medical care. As a matter of fact, statistics remain uncollected in some affected areas due to non-reporting cases. World Health Organization and other organizations proposed a plan for the eradication and control of the vector, although many of these plans were halted by the COVID-19 pandemic. Despite of the available drugs to treat these pathologies, it exists a lack of effectiveness against several parasite strains. Treatment protocols for diseases such as American trypanosomiasis (Chagas disease), leishmaniasis, and human African trypanosomiasis (HAT) have not achieved the desired results. Unfortunately, these drugs present limitations such as side effects, toxicity, teratogenicity, renal, and hepatic impairment, as well as high costs that have hindered the control and eradication of these diseases. This review focuses on the analysis of a collection of scientific shreds of evidence with the aim of identifying novel chalcogen-derived molecules with biological activity against Chagas disease, leishmaniasis and HAT. Compounds illustrated in each figure share the distinction of containing at least one chalcogen element. Sulfur (S), selenium (Se), and tellurium (Te) have been grouped and analyzed in accordance with their design strategy, chemical synthesis process and biological activity. After an exhaustive revision of the related literature on S, Se, and Te compounds, 183 compounds presenting excellent biological performance were gathered against the different causative agents of CD, leishmaniasis and HAT.

Synthesis and Antimicrobial Activity of New Heteroaryl(aryl) Thiazole Derivatives Molecular Docking Studies

Herein, we report the design, synthesis, and evaluation of the antimicrobial activity of new heteroaryl (aryl) thiazole derivatives. The design was based on a molecular hybridization approach. The in vitro evaluation revealed that these compounds demonstrated moderate antibacterial activity. The best activity was achieved for compound 3, with MIC and MBC in the range of 0.23–0.7 and 0.47–0.94 mg/mL, respectively. Three compounds (2, 3, and 4) were tested against three resistant strains, namely methicillin resistant Staphylococcus aureus, P. aeruginosa, and E. coli, which showed higher potential than the reference drug ampicillin. Antifungal activity of the compounds was better with MIC and MFC in the range of 0.06–0.47 and 0.11–0.94 mg/mL, respectively. The best activity was observed for compound 9, with MIC at 0.06–0.23 mg/mL and MFC at 0.11–0.47 mg/mL. According to docking studies, the predicted inhibition of the E. coli MurB enzyme is a putative mechanism of the antibacterial activity of the compounds, while inhibition of 14a-lanosterol demethylase is probably the mechanism of their antifungal activity.

Antibacterial and antibiofilm activities of thiazolidine-2,4-dione and 4-thioxo-thiazolidin-2-one derivatives against multidrug-resistant Staphylococcus aureus clinical isolates

AIMS

Antimicrobial resistance is one of the highest priorities in global public health with Staphylococcus aureus among the most important microorganisms due to its rapidly evolving antimicrobial resistance. Despite all the efforts of antimicrobial stewardship, research and development of new antimicrobials are still imperative. The thiazolidine ring is considered a privileged structure for the development of new antimicrobials. This study aimed to compare the antibacterial effects of two analog series of thiazolidine-2,4-dione and 4-thioxo-thiazolidin-2-one against multidrug-resistant Staphylococcus aureus clinical isolates.

METHODS AND RESULTS

The derivatives 1a, 2a, and 2b exhibited MIC between 1-32 μg.mL^-1 , with time-to-kill curves showing a bactericidal effect up to 24 h. In the antibiofilm assay, the most active derivatives were able to inhibit about 90% of biofilm formation. The 4-thioxo-thiazolidine-2-one derivatives were more active against planktonic cells, while the thiazolidine-2,4-dione derivatives were able to disrupt about 50% of the preformed biofilm. In the in vivo infection model using Caenorhabditis elegans as a host, the derivatives 1a, 2a, and 2b increased nematode survival with a concentration-dependent effect. Exposure of S. aureus to the derivatives 2a and 2b induced surface changes and decrease cell size. None of the derivatives was cytotoxic for human peripheral blood mononuclear cells (PBMC) but showed moderate cytotoxicity for L929 fibroblasts.

CONCLUSION

The 5-(3,4-dichlorobenzylidene)-4-thioxothiazolidin-2-one (2b) was the most active derivative against S. aureus and showed the higher selective indexes.

SIGNIFICANCE AND IMPACT OF STUDY

4-thioxo-thiazolidin-2-one are a promising scaffold for the research and development of new antimicrobial drugs against multidrug-resistant S. aureus.

Conformational Properties and Putative Bioactive Targets for Novel Thiosemicarbazone Derivatives

The structure assignment and conformational analysis of the thiosemicarbazones, DKI21 and DKI24, were performed through homonuclear and heteronuclear 2D Nuclear Magnetic Resonance (NMR) spectroscopy (2D-COSY, 2D-NOESY, 2D-ROESY, 2D-HSQC, and 2D-HMBC) and quantum mechanics (QM) calculations, using Functional Density Theory (DFT). In addition, utilizing a combination of 2D-NOESY and 2D-ROESY spectra an exo structure was established for both of the analogs. This experimental results were confirmed by theoretical mechanistic studies, as the lowest minima conformations derived through DFT calculations were compatible with the spatial correlations observed in the 2D-NOESY and 2D-ROESY spectra. Finally, molecular binding experiments were performed to detect the potential targets for DKI21 and DKI24, derived from SwissAdme. In silico molecular binding experiments showed favorable binding energy values for the most of the enzymes studied. The ADMET calculations, using the preADMET and pKCSm software, showed that the two molecules appear as possible drug leads.

Harnessing ROS-Induced Oxidative Stress for Halting Colorectal Cancer via Thiazolidinedione-Based SOD Inhibitors

Based on the "canonical" view of reactive oxygen species' (ROS) contribution to carcinogenesis, ROS induce oxidative stress and promote various tumor progression events. However, tumor cells also need to defend themselves against oxidative damage. This "heresy" was supported by several recent studies underlining the role of cellular antioxidant capacity in promoting metastasis and resistance to chemotherapy. Accordingly, harnessing the ROS-induced oxidative stress via selective suppression of the cancer antioxidant defense machinery has been launched as an innovative anticancer strategy. Within this approach, pharmacological inhibition of superoxide dismutases (SODs), the first-line defense antioxidant enzymes for cancer cells, selectively kills tumor cells and circumvents their acquired resistance. Various SOD inhibitors have been introduced, of which some were tolerated in clinical trials. However, the hit SOD inhibitors belong to diverse chemical classes and lack comprehensive structure-activity relationships (SAR). Herein, we probe the potential of newly synthesized benzylidene thiazolidinedione derivatives to inhibit SOD in colorectal cancer with special emphasis on their effects on correlated antioxidant enzymes aldehyde dehydrogenase 1 (ALDH1) and glutathione peroxidase (GPx). This may possibly bring a new dawn for utilizing thiazolidinediones (TZDs) in cancer therapy through SOD inhibition mechanisms. The preliminary 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that all of the evaluated TZDs exhibited excellent safety profiles on normal human cells, recording an EC100 of up to 47.5-folds higher than that of doxorubicin. Compounds 3c, 6a, and 6e (IC50 = 4.4-4.7 μM) were superior to doxorubicin and other derivatives against Caco-2 colorectal cancer cells within their safe doses. The hit anticancer agents inhibited SOD (IC50 = 97.2-228.8 μM). Then, they were selected for further in-depth evaluation on the cellular level. The anticancer IC50 doses of 3c, 6a, and 6e diminished the antioxidant activities of SOD (by 29.7, 70.1, and 33.3%, respectively), ALDH1A (by 85.92, 95.84, and 86.48%, respectively), and GPX (by 50.17, 87.03, and 53.28%, respectively) in the treated Caco-2 cells, elevating the Caco-2 cellular content of ROS by 21.42, 7.863, and 8.986-folds, respectively. Docking simulations were conducted to display their possible binding modes and essential structural features. Also, their physicochemical parameters and pharmacokinetic profiles formulating drug-likeness were computed.

Synthesis, Crystal Structures, Lipophilic Properties and Antimicrobial Activity of 5-Pyridylmethylidene-3-rhodanine-carboxyalkyl Acids Derivatives

The constant increase in the resistance of pathogenic bacteria to the commonly used drugs so far makes it necessary to search for new substances with antibacterial activity. Taking up this challenge, we obtained a series of rhodanine-3-carboxyalkyl acid derivatives containing 2- or 3- or 4-pyridinyl moiety at the C-5 position. These compounds were tested for their antibacterial and antifungal activities. They showed activity against Gram-positive bacteria while they were inactive against Gram-negative bacteria and yeast. In order to explain the relationship between the activity of the compounds and their structure, for selected derivatives crystal structures were determined using the X-ray diffraction method. Modeling of the isosurface of electron density was also performed. For all tested compounds their lipophilicity was determined by the RP-TLC method and by calculation methods. On the basis of the carried-out research, it was found that the derivatives with 1.5 N···S electrostatics interactions between the nitrogen atom in the pyridine moiety and the sulfur atom in the rhodanine system showed the highest biological activity.

A biodegradable film based on cellulose and thiazolidine bearing UV shielding property

The current rationale is exploring new eco-friendly UV- shielding films based on cellulose and thiazolidine. Cellulose was oxidized to dialdehyde cellulose (DAC) and tricarboxy cellulose (TCC) by periodate and TEMPO/periodate/hypochlorite, respectively. While E-3-amino-5-(phenyldiazenyl)-2-thioxothiazolidin-4-one (TH) was synthesized by coupling diazonium salt with the 5-methylene of 2-thioxo-4-thiazolidinone. DAC was then coupled with TH via Schiff base reaction and incorporated onto TCC with different ratios to get UV-shielding films. ¹HNMR, infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA) were used to investigate the chemical structure of the synthesized materials. In addition, the films' morphology, thermal, mechanical, and UV-shielding properties were investigated. The UV-shielding studies revealed that the film with 10% DAC-TH has 99.88, 99.99, and 96.19% UV-blocking (UVB), UV-absorbance (UVA), and Ultra-violet protection (UPF), respectively. Moreover, the prepared films demonstrated promising antimicrobial activity against Escherichia coli, S. aureus, P. aeruginosa, and Candida albicans. Finally, the prepared films showed no cytotoxic effects on normal human skin fibroblast's HFB-4 cell line.

2-{5-[(Z,2Z)-2-Chloro-3-(4-nitrophenyl)-2-propenylidene]-4-oxo-2-thioxothiazolidin-3-yl}-3-methylbutanoic Acid as a Potential Anti-Breast Cancer Molecule

It was established that the synthesis of hybrid molecules containing a thiazolidinone and a (2Z)-2-chloro-3-(4-nitrophenyl)prop-2-ene structural fragments is an effective approach for the design of potential anticancer agents. Given the results of the previous SAR-analysis, the aim of the study was to synthesize a novel 4-thiazolidinone derivative Les-3331 and investigate its molecular mechanism of action in MCF-7 and MDA-MB-231 breast cancer cells. The cytotoxic properties and antiproliferative potential of Les-3331 were determined. The effect of the tested compound on apoptosis induction and mitochondrial membrane potential was checked by flow cytometry. ELISA was used to determine caspase-8 and caspase-9, LC3A, LC3B, Beclin-1, and topoisomerase II concentration. Additionally, PAMPA, in silico or in vitro prediction of metabolism, CYP3A4/2D6 inhibition, and an Ames test were performed. Les-3331 possesses high cytotoxic and antiproliferative activity in MCF-7 and MDA-MB-231 breast cancer cells. Its molecular mechanism of action is associated with apoptosis induction, decreased mitochondrial membrane potential, and increased caspase-9 and caspase-8 concentrations. Les-3331 decreased LC3A, LC3B, and Beclin-1 concentration in tested cell lines. Topoisomerase II concentration was also lowered. The most probable metabolic pathways and no DDIs risk of Les-3331 were confirmed in in vitro assays. Our studies confirmed that a novel 4-thiazolidinone derivative represents promising anti-breast cancer activity.

Electrochemical and Spectral Studies on Benzylidenerhodanine for Sensor Development for Heavy Metals in Waters

Electrochemical and spectral studies of benzylidenerhodanine (BR) were performed in order to develop new sensors for heavy metals (HMs) based on chemically modified electrodes (CMEs). CMEs were obtained by cycling and by controlled potential electrolysis at different potentials and charges. Film formation was demonstrated by recording the CV curves of CMEs in transfer solutions containing ferrocene in 0.1 M TBAP/CH3CN. BR-CMEs were used for the analysis of HMs. Samples of Cd(II), Pb(II), Cu(II), and Hg(II), each possessing concentrations between 10−7 and 10−5 M, were analyzed by using CMEs prepared in different conditions. The most intense signal was obtained for the Pb(II) ion. These BR-CMEs can be used for the analysis of Pb(II) in monitored waters. An electrochemical study was performed at different concentrations of BR in 0.1 M TBAP/CH3CN on a glassy carbon electrode by differential pulse voltammetry, cyclic voltammetry, and rotating disk electrode voltammetry. The complexation ratio in the homogeneous solution has been established by the Mollard method in acetonitrile solutions.

The Current Directions of Searching for Antiparasitic Drugs

Parasitic diseases are still a huge problem for mankind. They are becoming the main cause of chronic diseases in the world. Migration of the population, pollution of the natural environment, and climate changes cause the rapid spread of diseases. Additionally, a growing resistance of parasites to drugs is observed. Many research groups are looking for effective antiparasitic drugs with low side effects. In this work, we present the current trends in the search for antiparasitic drugs. We report known drugs used in other disease entities with proven antiparasitic activity and research on new chemical structures that may be potential drugs in parasitic diseases. The described investigations of antiparasitic compounds can be helpful for further drug development.

Synthesis, Biological Evaluation and Molecular Docking Studies of 5-indolylmethylen-4-oxo-2-thioxothiazolidine Derivatives

Background: Infectious diseases represent a significant global strain on public health security and impact on socio-economic stability all over the world. The increasing resistance to the current antimicrobial treatment has resulted in the crucial need for the discovery and development of novel entities for the infectious treatment with different modes of action that could target both sensitive and resistant strains. Methods: Compounds were synthesized using the classical organic chemistry methods. Prediction of biological activity spectra was carried out using PASS and PASS-based web applications. Pharmacophore modeling in LigandScout software was used for quantitative modeling of the antibacterial activity. Antimicrobial activity was evaluated using the microdilution method. AutoDock 4.2® software was used to elucidate probable bacterial and fungal molecular targets of the studied compounds. Results: All compounds exhibited better antibacterial potency than ampicillin against all bacteria tested. Three compounds were tested against resistant strains MRSA, P.aeruginosa and E.coli and were found to be more potent than MRSA than reference drugs. All compounds demonstrated a higher degree of antifungal activity than the reference drugs bifonazole (6–17-fold) and ketoconazole (13–52-fold). Three of the most active compounds could be considered for further development of the new, more potent antimicrobial agents. Conclusion: Compounds 5b (Z)-3-(3-hydroxyphenyl)-5-((1-methyl-1H-indol-3-yl)methylene)-2-thioxothiazolidin-4-one and 5g (Z)-3-[5-(1H-Indol-3-ylmethylene)-4-oxo-2-thioxo-thiazolidin-3-yl]-benzoic acid as well as 5h (Z)-3-(5-((5-methoxy-1H-indol-3-yl)methylene)-4-oxo-2-thioxothiazolidin-3-yl)benzoic acid can be considered as lead compounds for further development of more potent and safe antibacterial and antifungal agents.

Evaluation of Anticancer and Antibacterial Activity of Four 4-Thiazolidinone-Based Derivatives

Heterocycles are commonly known for their unique features, e.g., antibacterial or anticancer properties. Although many synthetic heterocycles, such as 4-thiazolidinone (4-TZD), have been synthesized, their potential applications have not yet been fully investigated. However, many researchers have reported relevant results that can be a basis for the search for new potential drugs. Therefore, the aim of this study was to evaluate the cytotoxic, cytostatic, and antibacterial effects of certain 4-thiazolidinone-based derivatives, Les-3166, Les-5935, Les-6009, and Les-6166, on human fibroblasts (BJ), neuroblastoma (SH-SY5Y), epithelial lung carcinoma (A549), and colorectal adenocarcinoma (CACO-2) cell lines in vitro. All tested compounds applied in a concentration range from 10 to 100 µM were able to decrease metabolic activity in the BJ, A549, and SH-SY5Y cell lines. However, the action of Les-3166 was mainly based on the ROS-independent pathway, similarly to Les-6009. In turn, Les-5935 and Les-6166 were able to promote ROS production in BJ, A549, and SH-SY5Y cells, compared to the control. Les-3166, Les-6009, and Les-6166 significantly increased the caspase-3 activity, especially at the concentrations of 50 µM and 100 µM. However, Les-5935 did not induce apoptosis. Only Les-5935 showed a minor cytostatic effect on SH-SY5Y cells. Additionally, the antibacterial properties of the tested compounds against P. aeruginosa bacterial biofilm can be ranked as follows: Les-3166 > Les-5935 > Les-6009. Les-6166 did not show any anti-biofilm activity. In summary, the study showed that Les-5935, Les-6009, and Les-6166 were characterized by anticancer properties, especially in the human lung cancer cell. In cases of BJ, SH-SY5Y, and CACO-2 cells the anticancer usage of such compounds is limited due to effect visible only at 50 and 100 µM.

Design, Synthesis, Molecular Docking, and Evaluation Antioxidant and Antimicrobial Activities for Novel 3-Phenylimidazolidin-4-One and 2-Aminothiazol-4-One Derivatives

On our way to discovering and developing compounds that have an antioxidant impact compared to ascorbic acid and other biological activities, we designed, synthesized, and evaluated a new series of heterocyclic moieties drugs (1-11) as antioxidants and antimicrobial agents. As starting moieties, these new candidates were derived from two promising heterocyclic compounds, imidazoldin-4-one and thiazol-4-one. Firstly, diphenylimidazol 1 was obtained because of the cyclo condensation one-pot ternary reaction of urea, aniline, and chloroacetic acid under thermal conditions. Out of this starting compound, we could design and create new vital rings such as purine and triazine as in compounds 5 and 6, respectively. Secondly, the start thiazole derivative 7 was obtained from the intermolecular cyclization of thiourea, chloroacetic acid, p-nitobezaldehyde in the presence of sodium acetate. We synthesized various derivatives from this second starting compound 7 by being subjected to different reagents such as aniline, phenylenediamine, phenylhydrazine, and barbituric acid to yield 8, 9, 10, and 11, respectively. Using ascorbic acid as the standard compound, the pharmacological testing for antioxidant activity assessment of the produced derivatives was evaluated against ABTS (2,20-azinobis (3-ethylbenzothiazoline-6-sulfonic acid). Candidate 6 exhibited the best activity as an antioxidant agent compared to ascorbic acid as a reference compound. Moreover, all compounds were evaluated as antimicrobial agents against a series of bacteria and fungi. Among all synthesized compounds, compound 6 achieved high efficiency against two types of fungi and four kinds of bacteria, as Clotrimazole and Ampicillin were used as the reference agents, respectively. All chemical structures of the novel synthesized candidates were unequivocally elucidated and confirmed utilizing spectroscopical and elemental investigations.

Structure-activity relationship for the folding intermediate-selective inhibition of DYRK1A

DYRK1A phosphorylates proteins involved in neurological disorders in an intermolecular manner. Meanwhile, during the protein folding process of DYRK1A, a transitional folding intermediate catalyzes the intramolecular autophosphorylation required for the "one-off" inceptive activation and stabilization. In our previous study, a small molecule termed FINDY (1) was identified, which inhibits the folding intermediate-catalyzed intramolecular autophosphorylation of DYRK1A but not the folded state-catalyzed intermolecular phosphorylation. However, the structural features of FINDY (1) responsible for this intermediate-selective inhibition remain elusive. In this study, structural derivatives of FINDY (1) were designed and synthesized according to its predicted binding mode in the ATP pocket of DYRK1A. Quantitative structure-activity relationship (QSAR) of the derivatives revealed that the selectivity against the folding intermediate is determined by steric hindrance between the bulky hydrophobic moiety of the derivatives and the entrance to the pocket. In addition, a potent derivative 3 was identified, which inhibited the folding intermediate more strongly than FINDY (1); it was designated as dp-FINDY. Although dp-FINDY (3) did not inhibit the folded state, as well as FINDY (1), it inhibited the intramolecular autophosphorylation of DYRK1A in an in vitro cell-free protein synthesis assay. Furthermore, dp-FINDY (3) destabilized endogenous DYRK1A in HEK293 cells. This study provides structural insights into the folding intermediate-selective inhibition of DYRK1A and expands the chemical options for the design of a kinase inhibitor.

Tandem Michael addition/elimination – novel reactivity of pyridinium ylides in reaction with electron-deficient alkenes

Novel reactivity of pyridinium ylides in reaction with 4-oxothiazolidin-5-ylidenes as electron-deficient alkenes involving a tandem Michael addition/elimination process was developed to give double bond functionalization products in mild conditions.

Serendipitous synthesis of 2-alkenyl- and 2-aryl-4-thiazolidinones using dithiodiglycolic anhydride

Dithiodiglycolic anhydride undergoes an efficient formal cycloaddition with imines to afford functionalized 4-thiazolidinones, without complications arising from the anhydride-imine reaction or the sulfa-Michael reaction (in the case of 1,3-azadienes).

Development of a DABCO-Succinic Acid Based Catalytic System for the Aza-Michael Addition and Aza-Michael/Knoevenagel Tandem Reaction of Thiazolidine-2,4-dione to Electron Deficient Alkenes

A DABCO catalyzed aza-Michael addition of thiazolidine-2,4-dione to a variety of electron deficient alkenes has been developed. Additionally, a DABCO/succinic acid salt system has been designed that allows for the one pot tandem aza-Michael/Knoevenagel reaction of thiazolidine-2,4-dione to give difunctionalized thiazolidine-2,4-dione products. To the best of our knowledge, this is the first example of a one-pot tandem aza-Michael/Knoevenagel reaction involving thiazolidine-2,4-dione.

Synthesis of novel indole-thiazolidinone hybrid structures as promising scaffold with anticancer potential

A series of novel indole-azolidinone hybrids has been synthesized via Knoevenagel reaction of 5-fluoro-3-formyl-1H-indole-2-carboxylic acid methyl ester and some azolidinones differing in heteroatoms in positions 1, 2 and 4. Their anticancer activity in vitro was screened towards MCF-7 (breast cancer), HCT116 (colon cancer), HepG2 (hepatoma), HeLa (cervical cancer), A549 (lung cancer), WM793 (melanoma) and THP-1 (leukemia) cell lines, and a highly active 5-fluoro-3-(4-oxo-2-thioxothiazolidin-5-ylidenemethyl)-1H-indole-2-carboxylic acid methyl ester (3a) was identified and subjected to in-depth investigation of cytotoxicity mechanisms. This compound was found to possess the highest cytotoxic action towards tumor cells comparing with the action of other derivatives (1, 3b, 3c, 3d, 3e). Compound 3a exhibited toxicity toward MCF-7, HCT116, and A549, HepG2 cancer cells, while the non-malignant cells (human keratinocytes of HaCaT line and murine embryonic fibroblasts of Balb/c 3T3 line) possessed moderate sensitivity to it. The compound 3a induced apoptosis in studied tumor cells via caspase 3-, PARP1-, and Bax-dependent mechanisms; however, it did not affect the G1/S transition in HepG2 cells. The compound 3a impaired nuclear DNA in HepG2, HCT116, and MCF-7 cells without intercalating this biomolecule, but much less DNA damage events were induced by 3a in normal Balb/c 3T3 fibroblasts compared with HepG2 carcinoma cells. Thus, 5-fluoro-3-(4-oxo-2-thioxothiazolidin-5-ylidenemethyl)-1H-indole-2-carboxylic acid methyl ester 3a was shown to trigger DNA damage and induce apoptosis of human tumor cells and it might be considered as an anticancer agent perspective for in-depth studies.

Design, Synthesis, Cytotoxic Screening and Molecular Docking Studies of Novel Hybrid Thiosemicarbazone Derivatives as Anticancer Agents

Thiosemicarbazones have been the focus of scientists owing to their broad clinical anticancer range. Herein, A Series of new thiosemicarbazone derivatives 5-9 were synthesized and confirmed through the use of different spectroscopic techniques along with elemental analysis. The in vitro cytotoxic activity of compounds 5-9 against MCF-7 and A549 cell lines and normal breast cells were assessed. Several compounds were found to be active. The most active compound 7 caused MCF-7 cell cycle arrest at G1/ S phases; and induced apoptosis at the pre-G1 phase. The apoptosis-inducing activity of compound 7 was proofed by the elevation of caspase 3/7 activity and also by up-regulation of the expression of Bax and p53 proteins together with the down-regulation of the expression of the Bcl-2 protein. It also had a strong inhibitory effect topoisomerase IIβ enzyme. Molecular Docking study revealed that the synthesized compounds had good docking scores compared to the standard drug Etoposide towards the topoisomerase IIβ protein (3QX3). Overall, these findings confirmed that the new thiosemicarbazone derivatives could aid in the development of promising cancer drug candidates.

Multicomponent reaction for the synthesis of new 1,3,4-thiadiazole-thiazolidine-4-one molecular hybrids as promising antidiabetic agents through α-glucosidase and α-amylase inhibition

A simple and efficient protocol was developed to synthesize a new library of thiazolidine-4-one molecular hybrids (4a-n) via a one-pot multicomponent reaction involving 5-substituted phenyl-1,3,4-thiadiazol-2-amines, substituted benzaldehydes and 2-mercaptoacetic acid. The synthesized compounds were evaluated in vitro for their antidiabetic activities through α-glucosidase and α-amylase inhibition as well as their antioxidant and antimicrobial potentials. Compound 4e exhibited the most promising α-glucosidase and α-amylase inhibition with an IC50 value of 2.59 μM, which is ~1.5- and 14-fold superior as compared to the standard inhibitor acarbose. Structure-activity relationship (SAR) analysis revealed that the nature and position of substituents on the phenyl rings had a significant effect on the inhibitory potency.