Synthesis and biological evaluation of novel thiazolidinone derivatives as potential anti-inflammatory agents

Synthesis, antimicrobial, anti-inflammatory, antioxidant and cytotoxicity of new pyrimidine and pyrimidopyrimidine derivatives

A series of novel pyrimidine and pyrimidopyrimidine analogs were synthesized in good yield from 6-amino-4-aryl-2-oxo-pyrimidine-5-carbonitrile (1a-d). The synthesized compounds were characterized using various spectral studies, including FT-IR, 1H NMR, 13C NMR, mass spectrometry, and elemental analysis. Newly synthesized pyrimidopyrimidines and 2-(substituted-pyrazolyl)pyrimidine derivatives were assessed in vitro for their cytotoxic activities against three cancerous cell lines: colorectal carcinoma (HCT-116), mammary gland breast cancer (MCF-7), and hepatocellular carcinoma (HEPG-2), as well as normal fibroblasts (W138). The results indicated that compounds 3b, 10b, and 10c exhibited the highest cytotoxic activities, with IC50 values very close to those of the reference drug (doxorubicin) across all studied cancerous cell lines, while also demonstrating good safety effects on the normal human lung fibroblast cell line. Furthermore, all the synthesized compounds were examined for their antimicrobial activity against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), one Gram negative bacterium (Escherichia coli) and two fungal species (Candida albicans and Aspergillus flavus). The antimicrobial results of the synthesized compounds, when compared with the reference drugs ampicillin and clotrimazole, revealed that compounds 3a, 3b, 3d, 4a-d, 9c and 10b exhibited excellent antimicrobial activities. Moreover, membrane stabilization or anti-hemolytic activity was employed as a method to study the in vitro anti-inflammatory activity of the prepared heterocyclic compounds. Antioxidant activities were also assessed by measuring the percentage of free radical scavenging. Compounds 4b, 10c and 11a-c demonstrated strong anti-hemolytic and antioxidant effects, which can be attributed to their ability to protect red blood cells from hemolysis.

Synthesis of novel quinoline-thiazolobenzimidazolone hybrids as anticancer agents through caspase-dependent apoptosis

AIM

This work explores the synthesis of new bi-heterocyclic hybrid compounds based on quinoline ring and investigates their potential as anticancer agents.

MATERIALS & METHODS

The novel fused quinoline-thiazolo[3,2-a] benzimidazole-3(2 h)one hybrids were prepared by regioselective nucleophilic ring opening of the corresponding quinolinyl-oxiranes. In vitro cytotoxic activity was evaluated against human lung (A549) and gastric (AGS) cancer cell lines.

RESULTS

Global results showed that all tested compounds have promising inhibitory properties. Compounds 17 and 18 bearing two methoxy groups on the quinoline ring have exhibited remarkable and interesting activities. The investigation of the cell death process showed that these compounds activated a caspase-dependent apoptosis pathway. Results were further supported by molecular docking studies.

CONCLUSION

Both compounds exhibited good drug-like characteristics, which make them promising drug candidates.

PEG-Polymeric Nanocarriers Alleviate the Immunosuppressive Effects of Free 4-Thiazolidinone-Based Chemotherapeutics on T Lymphocyte Function and Cytokine Production

Purpose

Our study aimed to assess the effects of anticancer 4-thiazolidinone-based free water-insoluble therapeutics Les-3288 and Les-3833 and their waterborne complexes with branched PEG-containing polymeric carriers (A24-PEG550 and A24-PEG750) on immune response.

Methods

Human peripheral blood was used to study in vitro lymphocyte proliferative function, leukocyte phagocytic activity and respiratory burst, and cytokine production.

Results

The binding of the polymer to the anticancer drug Les-3288, which is intended to mitigate the immunosuppressive effects of the free drug on the proliferative activity of T lymphocytes and T-dependent B cells, demonstrated comparable efficacy for both A24-PEG750 and A24-PEG550 nanocarriers. Furthermore, it was observed that the drug-polymer complex significantly increased the reduced levels of IFN-γ and TNF-α resulting from free Les-3288. Conversely, the reduced levels of IL-6 and IL-4 remained unchanged. Administration of either form of Les-3288 had no effect on the phagocytic activity of monocytes, granulocytes or the respiratory burst of granulocytes. Due to the reduced cell viability and increased cytotoxicity associated with Les-3833, tenfold lower doses were selected for the immune assays. The effects of free Les-3833 on lymphocyte proliferative function resulted in significant stimulation of T-dependent B cells. The binding of Les-3833 to the smaller carrier, A24-PEG550 was found to maintain the stimulatory effect on B lymphocytes. While no effect of free Les-3833 on the granulocyte phagocytic activity was observed, binding of Les-3833 to both polymeric carriers resulted in a decrease in granulocyte phagocytic activity and respiratory burst, with no observable effect on monocytes. Monitoring of cytokine production showed no significant effect of either form of Les-3833 on the production of IFN-γ and IL-6. In the context of TNF-α and IL-4, the positive effect of polymer binding on restoring suppressed cytokine levels induced by the Les-3833 free drug was slightly more favorable for A24-PEG750.

Conclusion

The drug complexation with novel PEGylated carriers is a promising way for efficient therapeutic development.

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.

Design, synthesis, biological assessment and molecular modeling studies of novel imidazothiazole-thiazolidinone hybrids as potential anticancer and anti-inflammatory agents

A new series of imidazothiazole derivatives bearing thiazolidinone moiety (4a-g and 5a-d) were designed, synthesized and evaluated for potential epidermal growth factor receptor (EGFR) kinase inhibition, anticancer and anti-inflammatory activity, cardiomyopathy toxicity and hepatotoxicity. Compound 4c inhibited EGFR kinase at a concentration of 18.35 ± 1.25 µM, whereas standard drug erlotinib showed IC50 value of 06.12 ± 0.92 µM. The molecular docking, dynamics simulation and MM-GBSA binding energy calculations revealed strong interaction of compound 4c with binding site of EGFR. The synthesized compounds were evaluated for their anticancer activity by MTT assay against three human cancer cell lines A549 (Lung), MCF-7 (Breast), HCT116 (Colon), one normal human embryonic kidney cell line HEK293 and also for their EGFR kinase inhibitory activity. Few compounds of the series (4a, 4b, 4c) showed promising growth inhibition against all the tested cancer cell lines and against EGFR kinase. Among these, compound 4c was found to be most active and displayed IC50 value of 10.74 ± 0.40, 18.73 ± 0.88 against cancer cell lines A549 and MCF7 respectively whereas it showed an IC50 value of 96.38 ± 1.79 against HEK293 cell line indicating lesser cytotoxicity for healthy cell. Compounds 4a, 4b and 4c were also examined for their apoptosis inducing potential through AO/EB dual staining assay and it was observed that their antiproliferative activity against A549 cells is mediated via induction of apoptosis. Cardiomyopathy studies showed normal cardiomyocytes with no marked sign of pyknotic nucleus of compounds 4b and 4c. Hepatotoxicity studies of compounds 4b and 4c also showed normal architecture of hepatocytes. Compounds 4a-g and 5a-d were also evaluated for their in-vitro anti-inflammatory activity by protein albumin denaturation assay. Among the tested compounds 4a-d and 5a-b showed promising activity and were selected for in-vivo inflammatory activity against carrageenan rat paw edema test. Among these compounds, 4b was found to be most active in the series showing 84.94% inhibition, whereas the standard drug diclofenac sodium showed 84.57% inhibition. Compound 4b also showed low ulcerogenic potential and lipid peroxidation. Thus, compounds 4c and 4b could be a promising lead compounds for developing anticancer and anti-inflammatory agents with low toxicity and selectivity.

Docking, Synthesis and Evaluation of 4-hydroxy-1-phenyl-2(1H)-quinolone Derivatives as Anticancer Agents

BACKGROUND

The estimated number of cancer cases in India for the year 2022 was found to be 14,61,427. The development of chemotherapeutic agents has reduced the mortality rate, however, they have high toxicity which is a disadvantage. Many researchers have found out that quinolin-2- one possesses anticancer activity, with this background we thought of synthesizing the quinolin-2-one derivatives.

OBJECTIVE

This study aimed to carry out docking, synthesis, characterization, and evaluation of 2-(2- (4-Hydroxy-2-oxoquinolin-1(2H)-yl)phenyl/ substituted phenyl)-3-(phenylamino) thiazolidon-4-one derivatives (IVa-g) as an anticancer agent.

METHOD

Diphenylamine and malonic acid treated with phosphoryl chloride gave compound I, which on formylation afforded compound II, which on reaction with various substituted aromatic phenylhydrazine derivatives gave compounds IIIa-g, which on further reaction with thioglycolic acid and anhydrous zinc chloride yielded the compounds IVa-g.

RESULT

Among all the synthesized novel derivatives, compounds IV a-d showed 50% lysis in the IC50 range of 25-50μg for the A549 cell line, and compounds IVa, and IVb showed 50% lysis in the IC50 range of 25-50μg for the MDA-MB cell line. The compound, 3-((4-fluorophenyl)amino)-2-(2-(4- hydroxy-2-oxoquinolin-1(2H)-yl)phenyl)thiazolidin-4-one (IVg) was found to be the most active against both the cell line, A549 and MDA-MB with IC50 value of 0.0298μmol and 0.0338μmol respectively. The docking results revealed that the synthesized compounds exhibited well-conserved hydrogen bonding with one or more amino acid residues in the active pocket of EGFR tyrosine kinase domain with 4-anilinoquinazoline inhibitor erlotinib (PDB ID:1M17). Compound IVg showed the highest MolDock score of -137.813 compared to the standard drug Imatinib having a MolDock score of -119.354.

CONCLUSION

Compound IVg showed the highest MolDock score and was also found to be most potent against both the cell line, A549, and MDA-MB.

Design, synthesis, and biological evaluation of novel pleuromutilin derivatives containing benzimidazoles as effective anti-MRSA agents

A series of pleuromutilin derivatives containing benzimidazole were designed, synthesized, and evaluated for their antibacterial activities against Methicillin-resistant Staphylococcus aureus (MRSA) in this study. The in vitro antibacterial activities of the synthesized derivatives against four strains of S. aureus (MRSA ATCC 43300, S. aureus ATCC 29213, S. aureus 144, and S. aureus AD3) were determined by the broth dilution method. Among these derivatives, compound 58 exhibited superior in vitro antibacterial effect against MRSA (minimal inhibitory concentration [MIC] = 0.0625 μg/mL) than tiamulin (MIC = 0.5 μg/mL). Compound 58 possessed a faster bactericidal kinetic and a longer post-antibiotic effect time against MRSA than tiamulin. Meanwhile, at 8 μg/mL concentration, compound 58 did not display obviously cytotoxic effect on the RAW 264.7 cells. In addition, compound 58 (-2.04 log10 CFU/mL) displayed superior in vivo antibacterial efficacy than tiamulin (-1.02 log10 CFU/mL) in reducing MRSA load in mice thigh infection model. In molecular docking study, compound 58 can successfully attach to the 50S ribosomal active site (the binding free energy is -8.11 kcal/mol). Therefore, compound 58 was a potential antibacterial candidate for combating MRSA infections.

Group h Chitinase: A Molecular Target for the Development of Lepidopteran-Specific Insecticides

Sustainable agriculture requires insecticides that are selective between insects and mammals and even between harmful and beneficial insects. Lepidoptera includes the largest number of insect pests that threaten crops, and Hymenoptera contains the natural enemies for these pests. Discovery of lepidopteran-specific molecular targets is one route to develop such selective pesticides. Group h chitinase (Chi-h) is an ideal target for lepidopteran-specific insecticides because it is only distributed in Lepidoptera and is critical to their molting processes. This minireview focuses on the latest progress in developing Chi-h as a lepidopteran-specific insecticide target. We describe the biological function, crystal structure, and small-molecule inhibitors of the enzyme. Notably, two unique pockets were discovered in the crystal structure of Chi-h for the binding of the selective inhibitors, phlegmacin B₁ and lynamicin B. Moreover, lynamicin B was found to exhibit significant insecticidal activity toward lepidopteran pests but is harmless toward their natural enemies. These findings are advancing the development of selective insecticides to meet the needs of sustainable agriculture.

(2-Hydroxy-3-Methoxybenzylidene)thiazolo[3,2-a]pyrimidines: Synthesis, Self-Assembly in the Crystalline Phase and Cytotoxic Activity

A series of new 2-hydroxy-3-methoxybenzylidenethiazolo[3,2-a]pyrimidines with different aryl substituents at the 5 position are synthesized and characterized by ¹H/ ¹³C NMR and IR-spectroscopy and mass-spectrometry, as well as single crystal X-ray diffraction (SCXRD). It was demonstrated that the type of hydrogen bonding can play a key role in the chiral discrimination of these compounds in the crystalline phase. The hydrogen bond of the O-H...N type leads to 1D supramolecular heterochiral chains or conglomerate crystallization in the case of the formation of homochiral chains. The hydrogen bond of O-H...O type gave racemic dimers, which are packed into 2D supramolecular layers with a parallel or angular dimers arrangement. Halogen bonding of the N...Br or O...Br type brings a new motif into supramolecular self-assembly in the crystalline phase: the formation of 1D supramolecular homochiral chains instead 2D supramolecular layers. The study of cytotoxicity against various tumor cells in vitro was carried out. It was found that 2-hydroxy-3-methoxybenzylidenethiazolo[3,2-a]pyrimidines with 3-nitrophenyl substituent at C5 carbon atom demonstrated a high efficiency against M-HeLa (cervical adenocarcinoma) and low cytotoxicity against normal liver cells.

Hybrids of thiazolidinone with 1,2,3-triazole derivatives: design, synthesis, biological evaluation, in silico studies, molecular docking, molecular dynamics simulations, and ADMET profiling

A new series of thiazolidinone linked 1,2,3-triazole hybrids 5a-h was designed and synthesized using the copper-catalyzed Huisgen azide-alkyne cycloaddition (CuAAC) between thiazolidinone linked alkyne and aromatic azides. The structures of the newly synthesized compounds were established by NMR (1H and 13C) and HRMS. The targeted thiazolidinone-1,2,3-triazole hybrids were evaluated for their cytotoxic activity against four human cancer cell lines, including fibrosarcoma (HT-1080), lung carcinoma (A-549), and breast carcinoma (MCF-7 and MDA-MB-231) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliun bromide (MTT). The obtained data showed that most of these compounds have moderate anti-proliferative activity with IC50 values between 10.26 ± 0.71 and 53.93 ± 1.20 μM. The compound 5a exhibited higher activity with an IC50 value of 10.26 ± 0.71 µM, compared to 5d with an IC50 value of 11.56 ± 1.98 µM for the HT-1080 and MCF-7 cancer cells line, respectively. Moreover, Annexin-V apoptosis was assessed by flow cytometry for hybrid compounds 5a and 5d against HT-1080 and MCF-7 competitor cell lines, as they increase the level of active caspase 3/7. The experimental results were further confirmed by docking studies followed by molecular dynamic simulations. Both the potent derivatives i.e. 5a and 5d have comparable docking scores and MD simulations results showed that the docked complex of 5a is somewhat more stable than 5d primarily for protein p53. The ADMET profile of both derivatives established their safety zone and drug-like potential.Communicated by Ramaswamy H. Sarma.

Polymethoxyflavones from citrus peel: advances in extraction methods, biological properties, and potential applications

Citrus peel, as an effective component of citrus by-products, contains a large number of natural active components, including pectin, vitamins, dietary fiber, essential oil, phenolic compounds, flavonoids, and so on. With the development of the circular economy, citrus peel has attracted extensive concern in the food industry. The exploitation of citrus peel would assist in excavating potential properties and alleviating the environmental burden. Polymethoxyflavones (PMFs) exist almost in citrus peel, which have remarkable biological activities including antioxidant, anti-inflammatory, anti-cancer, and anti-obesity. Therefore, PMFs from citrus peel have the potential to develop as dietary supplements in the near future. Collectively, it is essential to take action to optimize the extraction conditions of PMFs and make the most of the extracts. This review mainly compiles several extraction methods and bioactivities of PMFs from citrus peel and introduces different applications including food processing, pharmaceutical industry, and plant rhizosphere to develop better utilization of citrus PMFs.

The anti-inflammatory activity of 2-iminothiazolidines: evidence for macrophage repolarization

Nowadays, macrophages are recognized as key cells involved in chronic inflammatory conditions, and play central roles in all inflammatory diseases and cancer. Due to their extensive involvement in the pathogenesis of inflammatory diseases, they are now considered a relevant therapeutic target in the development of new therapeutic strategies. 2-Iminothiazolidines are associated with important anti-inflammatory activity and represent a rich source for the development of new drugs and treatments. Our research focuses on evaluating the anti-inflammatory capacity of these compounds and their relationship with M1/M2 macrophage polarization. The results demonstrate that 2-iminothiazolidines have the capacity to decrease the levels of anti-inflammatory biomarkers, such as cytokines (IL-1β, TNF-α, and IL-6), nitric oxide synthase (with impact on NOx production), and COX-2, following a significant decline in NF-kB activation. We also observed an increase in levels of anti-inflammatory cytokines (IL-4 and IL-13) in the in vitro model of RAW 264.7 macrophages induced by LPS. Moreover, this is the first report, suggesting that the anti-inflammatory activity of 2-iminothiazolidines is associated with the ability to enhance phagocytosis, increase Arginase-1 and CD206 expression, and increase the secretion of IL-10. Furthermore, an in vivo study using the acute lung injury model induced by LPS proved the anti-inflammatory activity of a selected 2-iminothiazolidine, named methyl 2-(benzoylimino)-3-methyl-4-(4-nitrobenzyl)-1,3-thiazolidine-4-carboxylate. All these results, taken together, lead us to hypothesize that the mechanism of anti-inflammatory effect observed with this compound is closely related to the ability of this compound to produce macrophage repolarization, from the M1 to the M2 phenotype.

Synthesis of 6-Membered-Ring Fused Thiazine-Dicarboxylates and Thiazole-Pyrimidines via One-Pot Three-Component Reactions

A facile and efficient one-pot three-component reaction method for the synthesis of thiazine-dicarboxylates is reported. Reaction of an isocyanide and dialkyl acetylenedicarboxylate with 2-amino-4H-1,3-thiazin-4-one derivatives containing both an acidic proton and an internal nucleophile gave the products in good yields of 76-85%. The reactivity of dialkyl acetylenedicarboxylates was further tested in the synthesis of thiazole-pyrimidines where a two-component reaction of 2-aminothiazole with dialkyl acetylenedicarboxylates was successfully converted to a more efficient three-component reaction of a thiourea, α-haloketone and dialkyl acetylenedicarboxylate (DMAD/DEtAD) to give thiazole-pyrimidines in good yields of 70-91%.

Thiazolidinone-linked1,2,3-triazoles with monoterpenic skeleton as new potential anticancer agents: Design, synthesis and molecular docking studies

A novel series of 1,2,3-triazole-thiazolidinone-carvone hybrid compounds has been designed and synthesized using the copper-catalyzed Huisgen azide-alkyne 1,3-dipolar cycloaddition (CuAAC) process based on (R)-Carvone-O-propargylated 5-hydroxybenzylidene-thiazolidin-4-one derivative as starting material. All compounds were characterized and identified based on their NMR and HRMS spectroscopic data. HMBC correlations confirm that under the CuAAC reaction conditions, only the 1,4-disubstituted triazole regioisomers were formed. The targeted 1,2,3-triazole-thiazolidinone-carvone hybrids and their precursors were evaluated for their cytotoxic activity against four human cancer cell lines, including fibrosarcoma (HT-1080), lung carcinoma (A-549), and breast carcinoma (MCF-7 and MDA-MB-231). The obtained data showed that most of these compounds have moderate anti-proliferative activity with IC₅₀ values between 15.04 ± 0.71 and 42.22 ± 1.20 µM. The mechanism of action of the most active compounds 14e and 14f suggested that they induce apoptosis through caspase-3/7 activation, and the compound 14e elicited S-phase arrest, while compound 14f evoked G2/M phase blockade. The molecular docking confirmed that compounds 14e and 14f were nicely bonded with caspace-3 leading up to stable protein-ligand complexes.

Design, synthesis and screening of benzimidazole containing compounds with methoxylated aryl radicals as cytotoxic molecules on (HCT-116) colon cancer cells

A novel series of benzimidazole derivatives with methoxylated aryl groups was designed and synthesized as molecules with potential cytotoxic activity. In vitro cytotoxic activity over HCT-116 cells showed that N-(benzimidazothiazolone)acetamides 11a, 11b and 11c were found to be the most cytotoxic compounds compared camptothecin (CPT). The tested compounds had a dual topoisomerase I-β (Topo I-β) and tubulin inhibiting activities when compared to CPT and Podophyllotoxin (Podo) where, compounds l0a, l0b, 11a and 11b exhibited a potent inhibitory activity on Topo I-β enzyme in nano-molar concentration, on the other hand, compounds 12b and 13b exhibited the best inhibitory activity β-tubulin polymerization. Results of the cell cycle analysis as well as the results of annexin-V on HCT-116 cells showed that benzimidazothiazoles 12b and 13b had a pro-apoptotic activity higher than CPT by 1.33- and 1.30-folds, respectively. Moreover, the concentration of p53, Bax/Bcl-2 ratio and caspase 3/7 increased in compounds l0b, 11b, l2b, 13b, especially, compounds 11b and 13b exhibited an increased level of these mediators than CPT. Finally, compound 11b regulated the radiosensitizing activity of the HCT-116 cells by modulating the chromosomal instability.

One-Pot Synthesis of Benzimidazo[2,1-b]thiazoline Derivatives through an Addition/Cyclization/Oxidative Coupling Reaction

A novel and efficient approach to the synthesis of benzimidazo[2,1-b]thiazoline derivatives has been developed through an addition/cyclization/intramolecular oxidative C-H functionalization process. A variety of alkylene benzimidazo[2,1-b] thiazolines were conveniently assembled from the reaction of aryl isothiocyanate and propargylic amine in the presence of Cu(OAc)₂ and PIFA at room temperature. The product could be further converted to substituted benzimidazo[2,1-b]thiazole derivatives.

Synthesis, characterization and anti-inflammatory activity evaluation of 1,2,4-triazole and its derivatives as a potential scaffold for the synthesis of drugs against prostaglandin-endoperoxide synthase

Substituted 1,2,4-triazole nucleus is common in several drugs used in a variety of clinical conditions including infections, hypoglycemia, hypertension and cancer. In this study, we synthesized 1,2,4-triazole and its 16 hydrazone derivatives (B1-B16), characterized them by IR, NMR and Mass spectroscopy, and evaluated their radical scavenging and anti-inflammatory activities in vitro and in vivo. Out of 16 derivatives, five (B1, B5, B6, B9, and B13) demonstrated a significant radical scavenging and anti-inflammatory activity in vitro. B6, which possessed two electron-donating hydroxyl groups, was most active among all. Molecular docking and MD simulation of the complex of B6 with prostaglandin-endoperoxide synthase (PTGS) or cyclooxygenase (COX) showed that B6 occupied celecoxib binding site in COX with high affinity (the binding free energy of the complex with COX-1 was -10.5, and -11.2 kcal/mol with COX-2). Maximum anti-inflammatory activity was also shown by the B6 derivative in vivo, in the rat model of carrageenan-induced inflammation. B6, along with four other derivatives (B1, B5, B9 and B13) exhibited 80-90% free radical scavenging activity. The IC₅₀ values of these compounds were ≥40 µM. Griess nitrite and dichloro-dihydro-fluorescein-diacetate assays suggested a significant inhibition of nitric oxide and reactive oxygen species, especially by B6 and B9. Taken together, out of 16 derivatives, B6 is reported to have highest anti-inflammatory and antioxidant activity at a low dose level, which may be attributed to its two electron-donating hydroxyls. B6 is proposed to be an important scaffold for the synthesis of new drugs against PTGS for use in a myriad of inflammatory and infectious diseases.Communicated by Ramaswamy H. Sarma.

An expedient synthesis of new imino-thiazolidinone grafted dispiro-pyrrolidine-oxindole/indeno hybrids via a multicomponent [3+2] cycloaddition reaction in a deep eutectic solvent

A facile and selective synthesis of novel factionalized dispiro-pyrrolidines via a three component [3+2] cycloaddition reaction using a deep eutectic solvent.

Design and development of novel N-(pyrimidin-2-yl)-1,3,4-oxadiazole hybrids to treat cognitive dysfunctions

Novel hybrids bearing a 2-aminopyrimidine (2-AP) moiety linked to substituted 1,3,4-oxadiazoles were designed, synthesized and biologically evaluated. Among the developed compounds, 28 noncompetitively inhibited human acetylcholinesterase (hAChE; pIC₅₀ = 6.52; Ki = 0.17 µM) and showed potential in vitro antioxidant activity (60.0%) when evaluated using the Ellman's and DPPH assays, respectively. Compound 28 competitively displaced propidium iodide (PI) from the peripheral anionic site (PAS) of hAChE (17.6%) and showed high blood-brain barrier (BBB) permeability, as observed in the PAMPA-BBB assay. Additionally, compound 28 inhibited hAChE-induced Aβ aggregation in a concentration-dependent manner according to the thioflavin T assay and was devoid of neurotoxic liability towards SH-SY5Y cell lines, as demonstrated by the MTT assay. The behavioral studies of compound 28 in mice showed a significant reversal of scopolamine-induced amnesia, as observed in Y-maze and passive avoidance tests. Furthermore, compound 28 exhibited significant AChE inhibition in the brain in ex vivo studies. An evaluation of oxidative stress biomarkers revealed the antioxidant potential of 28. Moreover, in silico molecular docking and dynamics simulation studies were used as a computational tool to evaluate the interactions of compound 28 with the active site residues of hAChE.

5-Adamantan thiadiazole-based thiazolidinones as antimicrobial agents. Design, synthesis, molecular docking and evaluation

In continuation of our efforts to develop new compounds with antimicrobial properties we describe design, synthesis, molecular docking study and evaluation of antimicrobial activity of seventeen novel 2-{[5-(adamantan-1-yl)-1,3,4-thiadiazol-2-yl]-imino}-5-arylidene-1,3-thiazolidin-4-ones. All compounds showed antibacterial activity against eight Gram positive and Gram negative bacterial species. Twelve out of seventeen compounds were more potent than streptomycin and all compounds exhibited higher potency than ampicillin. Compounds were also tested against three resistant bacterial strains: MRSA, P. aeruginosa and E. coli. The best antibacterial potential against ATCC and resistant strains was observed for compound 8 (2-{[5-(adamantan-1-yl)-1,3,4-thiadiazol-2-yl]-imino}-5-(4-nitrobenzylidene)-1,3thiazolidin-4-one). The most sensitive bacterium appeared to be S. typhimirium, followed by B. cereus while L. monocitogenes and M. flavus were the most resistant. Compounds were also tested for their antifungal activity against eight fungal species. All compounds exhibited antifungal activity better than the reference drugs bifonazole and ketokonazole (3-115 times). It was found that compound 8 appeared again to be the most potent. Molecular docking studies on E. coli MurB, MurA as well as C. albicans CYP 51 and dihydrofolate reductase were used for the prediction of mechanism of antibacterial and antifungal activities confirming the experimental results.

2-{[(4-Hydroxy-3,5-dimethoxyphenyl)methylidene]hydrazinylidene}-4-oxo-1,3-thiazolidin-5-yl Acetic Acid

Thia-Michael addition of 2-[(4-hydroxy-3,5-dimethoxyphenyl)methylidene]hydrazine-1-carbothioamide (1) with maleic anhydride results in the formation of the title compound 2-{[(4-hydroxy-3,5-dimethoxyphenyl)methylidene]hydrazinylidene}-4-oxo-1,3-thiazolidin-5-yl acetic acid 2. The precursor 1 is synthesized by the reaction of 4-hydroxy-3,5-dimethoxybenzaldehyde and thiosemicarbazide in the presence of glacial acetic acid as the catalyst. The structure of the title compound is determined by elemental analysis, FT-IR, 1H-NMR, 13C-NMR and mass spectral data. In order to determine the molecular interactions with the bacterial enzyme, the title compound is further docked into the active site of the MurB protein of Staphylococcus aureus (PDB ID: 1HSK). The in vitro antibacterial and antifungal activity of the title compound is carried out in order to appraise its antimicrobial efficacy by determination of zone of inhibition and minimal inhibitory concentration. The compound is also evaluated for its antioxidant property by 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging assay.

Novel Thiazolidinone/Thiazolo[3,2-a]Benzimidazolone-Isatin Conjugates as Apoptotic Anti-proliferative Agents Towards Breast Cancer: One-Pot Synthesis and In Vitro Biological Evaluation

In connection with our research program on the development of new isatin-based anticancer candidates, herein we report the synthesis of two novel series of thiazolidinone-isatin conjugates (4a⁻n) and thiazolo[3,2-a]benzimidazolone-isatin conjugates (7a⁻d), and in vitro evaluation of their antiproliferative activity towards two breast cancer cell lines; triple negative MDA-MB-231, and MCF-7. Compounds 4m and 7b emerged as the most active congeners against MDA-MB-231 cells (IC50 = 7.6 ± 0.5 and 13.2 ± 1.1 µM, respectively). Compounds 4m and 7b were able to provoke apoptosis in MDA-MB-231 cells, evidenced by the up-regulation of Bax and down-regulation of Bcl-2, besides boosting caspase-3 levels. Hybrid 4m induced a fourfold increase in the percentage of cells at Sub-G₁, with concurrent arrest in G₂-M phase by 2.5-folds. Furthermore, hybrid 4m resulted in a sixfold increase in the percentage of annexin V-FITC positive apoptotic MDA-MB-231 cells as compared with the control. Moreover, the cytotoxic activities of the active conjugates were assessed towards two nontumorigenic cell lines (breast MCF-10A and lung WI-38) where both conjugates 4m and 7b displayed mean tumor selectivity index: 9.6 and 13.9, respectively. Finally, several ADME descriptors were predicted for the active conjugates via a theoretical kinetic study.

Design, synthesis and biological evaluation of novel pyridine-thiazolidinone derivatives as anticancer agents: Targeting human carbonic anhydrase IX

In order to obtain novel Human carbonic anhydrase IX (CAIX) inhibitors, a series of pyridine-thiazolidinone derivatives was synthesized and characterized by various spectroscopic techniques. The binding affinity of the compounds was measured by fluorescence binding studies and enzyme inhibition activity using esterase assay of CAIX. It was observed that compound 8 and 11 significantly inhibit the CAIX activity with the IC₅₀ value, 1.61 μM and 1.84 μM, respectively. The binding-affinity of compound 8 and 11 for CAIX was significantly high with their K_D values 11.21 μM and 2.32 μM, respectively. Docking studies revealed that compound 8 and 11 efficiently binds in the active site cavity of CA IX by forming sufficient numbers of H-bonds and van der Waals interactions with active side residues. All the compounds were further screened in vitro for anticancer activity and found that compound 8 and 11 exhibit considerable anticancer activity against MCF-7 and HepG-2 cell lines. All these findings suggest that compound 8 and 11 may be further exploited as a novel pharmacophore model for the development of anticancer agents.

Novel 2,4-dichlorophenoxy acetic acid substituted thiazolidin-4-ones as anti-inflammatory agents: Design, synthesis and biological screening

A library of fourteen 2-imino-4-thiazolidinone derivatives (1a-1n) has been synthesized and evaluated for in vivo anti-inflammatory activity and effect on ex-vivo COX-2 and TNF-α expression. Compounds 1k (5-(2,4-dichloro-phenooxy)-acetic acid (3-benzyl-4-oxo-thiazolidin-2-ylidene)-hydrazide) and 1m (5-(2,4-dichloro-phenooxy)-acetic acid (3-cyclohexyl-4-oxo-thiazolidin-2-ylidene)-hydrazide) exhibited in vivo inhibition of 81.14% and 78.80% respectively after 5h in comparison to indomethacin which showed 76.36% inhibition of inflammation without causing any damage to the stomach. Compound 1k showed a reduction of 68.32% in the level of COX-2 as compared to the indomethacin which exhibited 66.23% inhibition of COX-2. The selectivity index of compound 1k was found to be 29.00 in comparison to indomethacin showing selectivity index of 0.476. Compounds 1k and 1m were also found to significantly suppress TNF-α concentration to 70.10% and 68.43% in comparison to indomethacin which exhibited 66.45% suppression.

Thiazolidin-4-ones from 4-(methylthio)benzaldehyde and 4-(methylsulfonyl)benzaldehyde: Synthesis, antiglioma activity and cytotoxicity

The present study assessed the biological potential of fourteen 1,3-thiazolidin-4-ones evaluating the antiglioma effect through decreasing of cell viability of glioblastoma multiform cells. The new compounds were efficient synthesized through multicomponent or multicomponent one-pot procedures in moderate to good yields (22-86%) from two arenealdehydes (4-(methylthio)benzaldehyde and 4-(methylsulfonyl)benzaldehyde), seven amines (aromatic and aliphatic) and mercaptoacetic acid. The compounds were identified and characterized by GC/MS and NMR, five of them by HRMS. Six thiazolidinones showed significant effect of decreasing cell viability compared to standard drug TMZ at 100 μM in 72 h in C6 cell line by MTT assay. The compounds 5b, 5e, 5g and 6e showed the best results in the screening at 100 μM and were analyzed at different concentrations (5, 25, 50, 100 and 250 μM). Compounds 5b and 5e showed statistical difference at 5 μM, 6e at 25 μM and 5g at 50 μM in 72 h of treatment. The cytotoxicity study in primary astrocytes cells was evaluated and none of fourteen compounds showed toxicity at 100 μM, eight of them were not cytotoxic at 250 μM, both in 72 h. In addition, the propidium iodide assay demonstrated that the compounds might induce cell death by necrosis. In conclusion, this work reports at least four compounds (5b, 5e, 5g and 6e) with potential anti-tumor effect against glioblastoma multiform cell presenting activity at low concentrations and safe profile of cytotoxicity.

Synthesis and antifungal activity of dehydroabietic acid-based 1,3,4-thiadiazole-thiazolidinone compounds

In an attempt to search for new natural products-based antifungal agents, a series of novel dehydroabietic acid derivatives bearing a 1,3,4-thiadiazole-thiazolidinone moiety were designed and synthesized. The primary bioassay used showed that at a concentration of [Formula: see text], the target compounds 3c, 3f, and 3n exhibited excellent antifungal activity (91.3 % inhibition) against Gibberella zeae, which was equivalent to the commercial antifungal drug azoxystrobin (positive control).

2-Aryl-3-(2-morpholinoethyl)thiazolidin-4-ones: Synthesis, anti-inflammatory in vivo, cytotoxicity in vitro and molecular docking studies

Seven new 4-thiazolidinones bearing the morpholino moiety were easily synthesized by one-pot reactions of 4-(2-aminoethyl)morpholine (2-morpholinoethylamine), arenealdehydes and mercaptoacetic acid refluxing toluene for 19 h with moderate to good yields (45-97%). These novel compounds were fully identified and characterized by NMR spectroscopy and mass spectrometry. Thiazolidin-4-ones in vivo anti-inflammatory activities were determined using a croton oil-induced ear edema model of inflammation in BALB C mice. The best results were found for compounds 4c (49.20 mmol/kg), 4d (49.20 mmol/kg) and 4f (52.48 mmol/kg), which showed the ability to decrease the ear edema in mice by 50%, 48% and 54%, respectively, when compared to the standard drug indomethacin. In addition, the in vitro cytotoxicity activity of thiazolidin-4-ones against Vero cells was also performed and four compounds (4a, 4c, 4d and 4f) showed no toxic effect at 500 μg/mL. A docking simulation of compounds into the 1Q4G (COX-1) and 4PH9 (COX-2) enzymes binding site was conducted. This preliminary result will guide us in for further studies to improve the anti-inflammatory activity.

Molecular modeling and synthesis of some new 2-imino-4-thiazolidinone derivatives with promising TNF-α inhibitory activity

Out of 32 novel 2-imino-4-thiazolidinones, compounds 3f & 3g showed potent anti-inflammatory activity without causing any damage to the stomach.