Synthesis, structures, and cytotoxicity insights of organotin(IV) complexes with thiazole-appended pincer ligand.

Diorganotin complexes of the compositions [Me2Sn(L)] (1), [n-Bu2Sn(L)] (2), [Ph2Sn(L)]⋅C6H6 (3), [Bz2Sn(L)]⋅C6H6 (4) and [n-Oct2Sn(L)] (5) were synthesized by reacting R2SnO (R = Me, n-Bu, Ph, Bz or n-Oct) with the N2,N6-di(thiazol-2-yl)pyridine-2,6-dicarboxamide (H2L, where H2 denotes the two acidic protons) in refluxing toluene. Additionally, the mono-n-butyltin complex [n-BuSn(HL)Cl2]·H2O (6) was synthesized from n-BuSnCl3 and H2L in acetonitrile. Compounds were characterized by FT-IR, 1H, 13C and 119Sn NMR spectroscopy, while their solid-state structures were examined using single-crystal X-ray diffraction studies. In diorganotin compounds 1-5, the dianionic tridentate ligands (Npy, N-, N-) act as κ-N3 chelators. In 6, the L moiety (O, Npy, N-) acts as a κ-ON2 tridentate chelator, with involvement of one of the carboxamide oxygen atoms. The coordination polyhedron around the Sn(IV) ion is completed either by two axial Sn-R ligands in compounds 1-5 or by n-Bu and Cl ligands in compound 6, giving rise to distorted trigonal bipyramid or octahedral structures, respectively. The tin NMR results show that the penta-coordinated structures of compounds 1-5 and the hexacoordinated structure of compound 6, observed in the solid-state, are retained in solution. The in vitro antitumor activities of 1-5 were tested on T-47D breast cancer cells. Of these, diphenyltin compound 3 showed the highest anti-proliferative effect, with an IC50 of 10 ± 1.60 µM. Compound 3 exhibited selective toxicity, potentially inducing apoptosis via reactive oxygen species generation and nuclear changes, indicating promise as a breast cancer treatment. This study is the first to explore thiazole-appended organotin compounds for cytotoxicity.

Insight into the therapeutic potential of pyrazole-thiazole hybrids: A comprehensive review.

Several pyrazole-thiazole hybrids featuring two potentially bioactive pharmacophores with or without linker have been synthesized using the molecular hybridization approach as target structures by medicinal chemists to modulate multiple drug targets simultaneously. The presented review aims to provide an overview of the diversified and wide array of pharmacological activities of these hybrids bestowing anticancer, antifungal, antibacterial, analgesic, anti-inflammatory, antioxidant, antitubercular, antiviral, antiparasitic, and miscellaneous activities. The structure-activity relationships and potential mechanism of action are also reviewed to shed light on the development of more effective and biotargeted candidates. This review focuses on the latest research advances in the biological profile of pyrazole-thiazole hybrids reported from 2015 to the present, providing medicinal researchers with a comprehensive platform to rationally design and develop more promising pyrazole-thiazole hybrids.

Synthesis of New Thiazole-Privileged Chalcones as Tubulin Polymerization Inhibitors with Potential Anticancer Activities.

A series of novel thiazole-based chalcones were evaluated for their anticancer activity as potential tubulin polymerization inhibitors. In vitro anticancer screening for the thiazole derivatives 2a-2p exhibited broad-spectrum antitumor activity against various cancer cell lines particularly Ovar-3 and MDA-MB-468 cells with a GI50 range from 1.55 to 2.95 µΜ, respectively. Compound 2e demonstrated significant inhibition of tubulin polymerization, with an IC50 value of 7.78 µM compared to Combretastatin-A4 (CA-4), with an IC50 value of 4.93 µM. Molecular docking studies of compounds 2e, 2g, and 2h into tubulin further supported these findings, revealing that they bind effectively to the colchicine binding site, mirroring key interactions exhibited by CA-4. Computational predictions suggested favorable oral bioavailability and drug-likeness for these compounds, highlighting their potential for further development as chemotherapeutic agents.

Synthesis and antifungal activity of novel piperidinyl thiazole derivatives.

BACKGROUND: As an investigative program around the development of novel oomycetes fungicides, a systematic exploration of piperidinyl thiazole fungicides employing a bioisosteric replacement strategy was planned. RESULTS: A series of novel piperidinyl thiazole analogues were designed, synthesised, and evaluated as fungicides in vitro and in vivo against three oomycete fungal pathogens: Phytophthora infestans (P. infestans), Plasmopara viticola (P. viticola), and Pseudoperonospora cubensis (P. cubensis). Variation at four different regions of piperidinyl thiazole fungicides like Oxathiapiprolin and Fluoxapiprolin was considered. All variations delivered excellent in vitro and in vivo activity against P. infestans at extremely low concentrations. O-linked heterocyles, bicyclic piperidines, and sulfoximine-substituted aryls demonstrated the most robust transfer of in vitro activity into the greenhouse, while pyridones, acylated sulfoximines, and sultams showed less consistent results concerning the transfer. Specific compounds were selected for deeper evaluation of oomycetes activity. Several of them with representatives of all the series showed an excellent in vivo activity against P. viticola and P. cubensis. Among the most active compounds, P14 and P25 were further profiled in advanced studies and were found to have a robust curative potential. P14, P15, and P25 provided excellent control of P. infestans (in potato), P. viticola (in grapes), and P. cubensis (in cucumber) in field trials at dose rates of 20 and 30 g per hectare. CONCLUSIONS: A bioisosteric replacement strategy was successfully employed to identify novel piperidine thiazole derivatives with robust and commercially interesting control of oomycetes diseases in the greenhouse and under field conditions. A systematic exploration of various modifications of the piperidine thiazole class and their structure activity relationships was described. © 2024 Society of Chemical Industry.

Synthesis of New Chromen-5-one Derivatives from Dimedone and their Antiproliferative Evaluations against Selected Cancer Cell Lines Together with Hepatocellular Carcinoma and Cervical Carcinoma.

BACKGROUND: The coumarin nuclei, which exist in many heterocyclic compounds, has gained a lot of attention over the past decade due to their wide range of biological activities such as antibacterial, anticoagulant, antiviral, antifungal, anticancer, and anti-inflammatory properties. OBJECTIVE: The multi-component reactions of 5,5-dimethylcyclohexane-1,3-dione with acetophenone derivatives and triethoxymethane produced biologically active target chromene molecules and their fused derivatives. METHODS: The reaction of 5,5-dimethylcyclohexane-1,3-dione and each of triethoxymethane and acetophenone derivatives 3a-g in absolute ethanol containing triethylamine gave the 4,6,7,8-tetrahydro-5H-chromen-5-one derivatives 4a-g. Compounds 4a-d were used for further heterocyclization reactions to produce biologically active fused pyrazole, thiophene, and thiazole derivative corporate with the chromenes caffold. RESULTS: The cytotoxicity of the synthesized compounds were evaluated using six cancer cell lines together with c-Met kinase and PC-3 cell line inhibitions. In addition, cytotoxicity toward hepatocellular carcinoma HepG2 and cervical carcinoma HeLa was carried out as well as the in-vitro cytotoxic potential for all compounds against peripheral blood lymphocytes (PBL) extracted from healthy donors. Morphological changes of the A549 cell line by the two most active compounds were also studied. CONCLUSION: The synthesized heterocyclic compounds were originally obtained from 5,5-dimethylcyclohexane1,3-dione. Several of the produced compounds exhibited high inhibitions toward several cancer cell lines proving high inhibitions, therefore, encouraging further studies to synthesize heterocyclic compounds based on chromene scaffold.

Effect of Thiophene-Hydrazinyl-Thiazole derivative as an efficient dye sensitizer and performance enhancer of TiO2 toward rhodamine B photodegradation.

Visible-light-driven photocatalysis is an eco-friendly technology for wastewater treatment, where TiO2-based photocatalysts displayed outstanding performance in this regard. Dye sensitization is a promising approach for overcoming the common drawbacks of TiO2via improving its photocatalytic performance and extending its activity to visible light. Herein, we demonstrate the synthesis of the Thiophene-Hydrazinyl-Thiazole (THT) derivative as a novel organic dye sensitizer to be employed as a visible-light antenna for TiO2 nanoparticles. The physicochemical characteristics of the as-synthesized TiO2-based nanoparticles are examined by different techniques, which revealed the successful fabrication of the proposed THT-TiO2 heterojunction. The incorporation of THT molecules on the TiO2 surface led to slight disorders and deformation in the crystal lattice of TiO2, a remarkable improvement of its absorption in the visible light as a perfect visible-light antenna in the whole visible region, and significant enhancement in the charge transfer. Rhodamine B (RhB) is used as an organic dye model to assess the photocatalytic efficiency of the as-fabricated THT-TiO2 photocatalyst which achieved almost complete degradation (>95% in 150 min) with an observed rate constant (kobs) of 0.0164 min-1; total organic carbon (TOC) measurements suggested ∼75% mineralization. THT-TiO2 achieved 2.1-fold enhancement in photodegradation% and 4.1-fold enhancement in kobs compared to the bare TiO2. THT showed good activity under visible-light irradiation (RhB degradation% was >66% in 150 min and kobs = 0.0085 min-1). The influence of the initial pH of the solution was investigated and pH 4 was the optimum pH value for suitable interaction between RhB and the surface of THT-TiO2. Radical quenching experiments were conducted to assess the crucial reactive species where the ∙OH and O2.- were the most reactive species. THT-TiO2 showed promising stability over three successive cycles. Finally, the improvement mechanism of the photocatalytic activity of THT-TiO2 was attributed to the electron injection from the excited THT (the dye sensitizer) to TiO2 and enhanced charge separation.

Synthesis, Cytotoxicity and Antioxidant Activity Evaluation of Some Thiazolyl-Catechol Compounds.

A series of thiazolyl-catechol compounds with antioxidant and cytotoxic activities were synthesized by a Hantzsch heterocyclization, using diverse thioamides as the thiocarbonyl component and 4-chloroacetyl-catechol as haloketone. These compounds were characterized by MS, IR spectroscopy, and NMR. Their antioxidant potential was evaluated by antiradical, electron transfer, and ferrous ion chelation assays using ascorbic acid, Trolox, and EDTA-Na2 as references. The cytotoxicity of the synthesized compounds was evaluated on two different cell types, normal human foreskin fibroblasts (BJ) and human pulmonary malignant cells (A549), using gefitinib as a reference anticancer drug. The results obtained from the tests highlighted compounds 3g and 3h with significant antioxidant activities. The highest cytotoxic potency against A549 cells was exhibited by compounds 3i and 3j, while compound 3g demonstrated exceptional selectivity on malignant cells compared to gefitinib. These promising results encourage further investigation into targeted modifications on position 2 of the thiazole ring, in order to develop novel therapeutic agents.

Design, synthesis, and hypoxia-inducible factor-1α inhibitory activity evaluation of panaxadiol derivatives containing a thiazole moiety.

The hypoxia-inducible factor-1α (HIF-1α) pathway has been implicated in tumor angiogenesis, growth, and metastasis. Therefore, the inhibition of this pathway is an important therapeutic target for cancer. Here, three series of panaxadiol derivatives containing a thiazole moiety (5a-l, 7a-i, and 9a-i) were synthesized and evaluated for HIF-1α inhibitory activity using a Hep3B cell-based luciferase reporter assay. Compounds 5d and 7b showed the strongest inhibitory activity with IC50 values of 17.37 and 6.42 µM, respectively, and did not show any significant cytotoxicity. Western blot assay results indicated that these two compounds exhibited more potent inhibition, compared with panaxadiol, of the expression of HIF-1α protein in Hep3B cells at a concentration of 50 µM. Molecular docking experiments were also performed to investigate the structure-activity relationship.

Isomers of n-Type Poly(thiophene-alt-co-thiazole) for Organic Thermoelectrics.

n-Type polythiophene represents a promising category of n-type polymer thermoelectric materials known for their straightforward structure and scalable synthesis. However, n-type polythiophene often suffers from a twisted backbone and poor stacking property when introducing high-density electron-withdrawing groups for a lower lowest unoccupied molecular orbital (LUMO) level, which is considered to be beneficial for n-doping efficiency. Herein, we developed two isomers of polythiophene derivatives, PTTz1 and PTTz2, by inserting thiazole units into the polythiophene backbone composed of thieno[3,4-c]pyrrole-4,6-dione (TPD) and thiophene-3,4-dicarbonitrile (2CNT). Although PTTz1 and PTTz2 share a similar polymer skeleton, they differ in thiazole configuration, with the nitrogen atoms of the thiazole units oriented toward TPD and 2CNT, respectively. The insertion of thiazole units significantly planarizes the polythiophene backbone while largely preserving low LUMO levels. Notably, PTTz2 exhibits a more coplanar backbone and closer π-stacking compared to PTTz1, resulting in a greatly enhanced electron mobility. Both PTTz1 and PTTz2 can be easily n-doped due to their deep LUMO levels. PTTz2 demonstrates superior thermoelectric performance, with an electrical conductivity of 50.3 S cm-1 and a power factor of 23.8 µW m-1 K-2, which is approximately double that of PTTz1. This study highlights the impact of the thiazole unit on n-type polythiophene derivatives and provides valuable guidelines for the design of high-performance n-type polymer thermoelectric materials.

Multicomponent reaction for synthesis, molecular docking, and anti-inflammatory evaluation of novel indole-thiazole hybrid derivatives.

In this article, novel thiazol-indolin-2-one derivatives 4a-f have been synthesized via treatment of thiosemicarbazide (1) with some isatin derivative 2a-f and N-(4-(2-bromoacetyl)phenyl)-4-tolyl-sulfonamide (3) under reflux in ethanol in the presence of triethyl amine (TEA). The structures of new products were elucidated by elemental and spectral analyses. Moreover, all compounds were investigated for their in vivo anti-inflammatory activity using celecoxib as a reference drug. The target compound 4b was the most active anti-inflammatory candidate and exhibited higher edema inhibition (EI = 38.50%) than that recorded by celecoxib (EI = 34.58%) after 3 h. Furthermore, the most active compounds 4b and 4f were subjected to a molecular docking study inside COX-2 enzyme to show their binding interactions. Both compounds 4b and 4f showed good fitting into COX-2 binding site with docking energy scores - 11.45 kcal/mol and - 10.48 kcal/mol, respectively which indicated that compound 4b revealed the most promising and effective anti-inflammatory potential.

Unveiling anti-diabetic potential of new thiazole-sulfonamide derivatives: Design, synthesis, in vitro bio-evaluation targeting DPP-4, α-glucosidase, and α-amylase with in-silico ADMET and docking simulation.

Diabetes mellitus type 2 (T2DM) can be managed by targeting dipeptidyl peptidase-4 (DPP-4), an enzyme that breaks down and deactivates peptides such as GIP and GLP-1. In this context, a new series of 2-(2-substituted hydrazineyl)thiazole derivatives 4, 5, 6, 8, 10, and 11 conjugated with the 2-hydroxy-5-(pyrrolidin-1-ylsulfonyl)benzylidene fragment were designed and synthesized. The virtual screening of the designed derivatives inside DPP-4 demonstrated good to moderate activity, with binding affinity ranging from -6.86 to -5.36 kcal/mol compared to Sitagliptin (S=-5.58 kcal/mol). These results encourage us to evaluate DPP-4 using in-vitro fluorescence-based assay. The in-vitro results exhibited inhibitory percentage (IP) values ranging from 40.66 to 75.62 % in comparison to Sitagliptin (IP=63.14 %) at 100 µM. Subsequently, the IC50 values were determined, and the 5-aryl thiazole derivatives 10 and 11 revealed strong potent IC50 values 2.75 ± 0.27 and 2.51 ± 0.27 µM, respectively, compared to Sitagliptin (3.32 ± 0.22 µM). The SAR study exhibited the importance of the substituents on the thiazole scaffold, especially with the hydrophobic fragment at C5 of the thiazole, which has a role in the activity. Compounds 10 and 11 were further assessed toward α-glucosidase and α-amylase enzymes and give promising results. Compound 10 showed good activity against α-glucosidase with IC50 value of 3.02 ± 0.23 µM compared to Acarbose 3.05 ± 0.22 µM and (11 = 3.34 ± 0.10 µM). On the other hand, for α-amylase, compound 11 was found to be most effective with IC50 value of 2.91 ± 0.23 µM compared to compound 10 = 3.30 ± 0.16 µM and Acarbose (2.99 ± 0.21 µM) indicating that these derivatives could reduce glucose by more than one target. The most active derivatives 10 and 11 attracted great interest as candidates for oral bioavailability and safe toxicity profiles compared to positive controls. The in-silico docking simulation was performed to understand the binding interactions inside the DPP-4, α-glucosidase, and α-amylase pockets, and it was found to be promising antidiabetic agents through a number of interactions.

Development of non-acidic 4-methylbenzenesulfonate-based aldose reductase inhibitors; Design, Synthesis, Biological evaluation and in-silicostudies.

Design and virtual screening of a set of non-acidic 4-methyl-4-phenyl-benzenesulfonate-based aldose reductase 2 inhibitors had been developed followed by chemical synthesis. Based on the results, the synthesized compounds 2, 4a,b, 7a-c, 9a-c, 10a-c, 11b,c and 14a-c inhibited the ALR2 enzymatic activity in a submicromolar range (99.29-417 nM) and among them, the derivatives 2, 9b, 10a and 14b were able to inhibit ALR2 by IC50 of 160.40, 165.20, 99.29 and 120.6 nM, respectively. Moreover, kinetic analyses using Lineweaver-Burk plot revealed that the most active candidate 10a inhibited ALR2 potently via a non-competitive mechanism. In vivo studies showed that 10 mg/kg of compound 10a significantly lowered blood glucose levels in alloxan-induced diabetic mice by 46.10 %. Moreover, compound 10a showed no toxicity up to a concentration of 50 mg/kg and had no adverse effects on liver and kidney functions. It significantly increased levels of GSH and SOD while decreasing MDA levels, thereby mitigating oxidative stress associated with diabetes and potentially attenuating diabetic complications. Furthermore, the binding mode of compound 10a was confirmed through MD simulation. Noteworthy, compounds 2 and 14b showed moderate antimicrobial activity against the two fungi Aspergillus fumigatus and Aspergillus niger. Finally, we report the thiazole derivative 10a as a new promising non-acidic aldose reductase inhibitor that may be beneficial in treating diabetic complications.

The therapeutic value of thiazole and thiazolidine derivatives in Alzheimer's disease: a systematic literature review.

Background and purpose: Alzheimer's disease (AD) is a common neurodegenerative disease and the fifth leading cause of death among the elderly. The development of drugs for AD treatment is based on inhibiting cholinesterase (ChE) activity and inhibiting amyloid-beta peptide and tau protein aggregations. Many in vitro findings have demonstrated that thiazole-and thiazolidine-based compounds have a good inhibitory effect on ChE and other elements involved in the AD pathogenicity cascade. Experimental approach: In the present review, we collected available documents to verify whether these synthetic compounds can be a step forward in developing new medications for AD. A systematic literature search was performed in major electronic databases in April 2021. Twenty-eight relevant in vitro and in vivo studies were found and used for data extraction. Findings/Results: Findings demonstrated that thiazole-and thiazolidine-based compounds could ameliorate AD's pathologic condition by affecting various targets, including inhibition of ChE activity, amyloid-beta, and tau aggregation in addition to cyclin-dependent kinase 5/p25, beta-secretase-1, cyclooxygenase, and glycogen synthase kinase-3ß. Conclusion and implications: Due to multitarget effects at micromolar concentration, this review demonstrated that these synthetic compounds could be considered promising candidates for developing anti-Alzheimer drugs.

Thiazolation of phenylthiosemicarbazone to access new thiazoles: anticancer activity and molecular docking.

Aim: Novel thiazole hybrids were synthesized via thiazolation of 4-phenylthiosemicarbazone (4). Materials & methods: The anticancer activity against the NCI 60 cancer cell line panel. Results: Methyl 2-(2-((1-(naphthalen-2-yl)ethylidene)hydrazineylidene)-4-oxo-3-phenylthiazolidin-5-ylidene)acetate (6a) showed significant anticancer activity at 10 µM with a mean growth inhibition (GI) of 51.18%. It showed the highest cytotoxic activity against the ovarian cancer OVCAR-4 with an IC50 of 1.569 ± 0.06 µM. Compound 6a inhibited PI3Kα with IC50 = 0.225 ± 0.01 µM. Moreover, compound 6a revealed a decrease of Akt and mTOR phosphorylation in OVCAR-4 cells. In addition, antibacterial activity showed that compounds 11 and 12 were the most active against Staphylococcus aureus. Conclusion: Compound 6a is a promising molecule that could be a lead candidate for further studies.

Novel naphthalene-azine-thiazole hybrids 5-12 were synthesized via late-stage thiazolation of the corresponding 4-phenylthiosemicarbazone 4. Compound 6a showed significant anticancer activity at single-dose screening and yielded excellent inhibitory activity with a mean GI of 51.18%. Compound 6a showed the highest cytotoxic activity against OVCAR-4 with an IC₅₀ of 1.569 ± 0.06 µM. Moreover, compound 6a exhibited an IC₅₀ of 31.89 ± 1.19 µM against normal ovarian cell line (OCE1) and a selectivity index of 19.1. Compound 6a inhibited PI3Kα with IC₅₀ = 0.225 ± 0.01 µM compared with alpelisib (IC₅₀ = 0.061 ± 0.003 µM). Moreover, compound 6a revealed a powerful decrease of Akt and mTOR phosphorylation in the OVCAR-4 cell line. The cell cycle analysis showed that compound 6a caused an arrest at the G2/M phase. The compound also increased the total apoptosis by 26.8-fold and raised the level of caspase-3 by 4.34 times in OVCAR-4. In addition, antibacterial activity was estimated against Gram-positive and Gram-negative bacterial strains. Compounds 11 and 12 were the most active derivatives, with MIC value of 256 µg/ml against Staphylococcus aureus. Molecular docking was done and showed that 6a interlocked and fitted well into the ATP binding site of PI3Kα kinase (Protein Data Bank ID: 4JPS) with a fitness value (-119.153 kcal/mol) and forms the key H-bonds with Val851 and Ser854 like the marketed PI3Kα inhibitor alpelisib. Consequently, 6a is the most promising molecule that could be a lead candidate for further studies.

Ferrocenyl Azoles: Versatile N-Containing Heterocycles and their Anticancer Activities.

The medicinal chemistry of ferrocene has gained its momentum after the discovery of biological activities of ferrocifen and ferroquine. These ferrocenyl drugs have been designed by replacing the aromatic moiety of the organic drugs, tamoxifen and chloroquine respectively, with a ferrocenyl unit. The promising biological activities of these ferrocenyl drugs have paved a path to explore the medicinal applications of several ferrocenyl conjugates. In these conjugates, the ferrocenyl moiety has played a vital role in enhancing or imparting the anticancer activity to the molecule. The ferrocenyl conjugates induce the cytotoxicity by generating reactive oxygen species and thereby damaging the DNA. In medicinal chemistry, the five membered nitrogen heterocycles (azoles) play a significant role due to their rigid ring structure and hydrogen bonding ability with the biomolecules. Several potent drug candidates with azole groups have been in use as chemotherapeutics. Considering the importance of ferrocenyl moiety and azole groups, several ferrocenyl azole conjugates have been synthesized and screened for their biological activities. Hence, in the view of a wide scope in the development of potent drugs based on ferrocenyl azole conjugates, herein we present the details of synthesis and the anticancer activities of ferrocenyl compounds bearing azole groups such as imidazole, triazoles, thiazole and isoxazoles.

Design, Synthesis of 3-(Aryl)-1-(2-p-tolylthiazol-4-yl)prop-2-en-1-ones as Alpha(α)-Amylase Inhibitors.

α-Amylase inhibition is vital in controlling diabetic complications. Herein, we have synthesized a hybrid scaffold based on thiazole-chalcone to access α-amylase inhbition. The proposed structures were verified with spectroscopic techniques (UV-Vis., FT-IR, 1H-, 13C-NMR, and elemental analysis). The synthesized compounds were evaluated for their α-amylase and antioxidant potential. In vitro hemolytic assay was performed to test biocompatibility of all compounds. Among tested compounds, 4 c (IC50=3.8 µM), 4 g (IC50=14.5 µM), and 4 f (IC50=17.1 µM) were found excellent α-amylase inhibitors. However, none of the tested compounds exhibited significant antioxidant activity. All compounds showed less lysis than Triton X-100, but compounds 4 f and 4 h had the least lysis at all tested concentrations and were found to be safe for human erythrocytes. Molecular docking study was performed to evaluate the binding interactions of ligands with human pancreatic α-amylase (HPA). The binding score -8.09 to -8.507 kcal/mol revealed strong binding interactions in the ligand-protein complex. The docking results supplemented the observed α-amylase inhibition and hence augment the scaffold to serve as leads for the antidiabetic drug development.

Assessing the Effects of Thiazole-Carboxamide Derivatives on the Biophysical Properties of AMPA Receptor Complexes as a Potential Neuroprotective Agent.

An optimal balance between excitatory and inhibitory transmission in the central nervous system provides essential neurotransmission for good functioning of the neurons. In the neurology field, a disturbed balance can lead to neurological diseases like epilepsy, Alzheimer's, and Autism. One of the critical agents mediating excitatory neurotransmission is α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors, which are concerned with synaptic plasticity, memory, and learning. An imbalance in neurotransmission finally results in excitotoxicity and neurological pathologies that should be corrected through specific compounds. Hence, the current study will prove to be an evaluation of new thiazole-carboxamide derivatives concerning AMPAR-modulating activity and extended medicinal potential. In the current project, five previously synthesized thiazole-carboxamide derivatives, i.e., TC-1 to TC-5, were used to interact with the AMPARs expressed in HEK293T cells, which overexpress different subunits of the AMPAR. Patch-clamp analysis was carried out while the effect of the drugs on AMPAR-mediated currents was followed with a particular emphasis on the kinetics of inhibition, desensitization, and deactivation. All tested TC compounds, at all subunits, showed potent inhibition of AMPAR-mediated currents, with TC-2 being the most powerful for all subunits. These compounds shifted the receptor kinetics efficiently, mainly enhancing the deactivation rates, and hence acted as a surrogate for their neuroprotective potentials. Additionally, recently published structure-activity relationship studies identified particular substituent groups as necessary for improving the pharmacologic profiles of these compounds. In this regard, thiazole-carboxamide derivatives, particularly those classified as TC-2, have become essential negative allosteric modulators of AMPAR function and potential therapeutics in neurological disturbances underlain by the dysregulation of excitatory neurotransmission. Given their therapeutic effectiveness and safety profiles, these in vivo studies need to be further validated, although computational modeling can be further developed for drug design and selectivity. This will open possibilities for new drug-like AMPAR negative allosteric modulators with applications at the clinical level toward neurology.

Cholinesterase Inhibition and Antioxidative Capacity of New Heteroaromatic Resveratrol Analogs: Synthesis and Physico-Chemical Properties.

The targeted compounds in this research, resveratrol analogs 1-14, were synthesized as mixtures of isomers by the Wittig reaction using heterocyclic triphenylphosphonium salts and various benzaldehydes. The planned compounds were those possessing the trans-configuration as the biologically active trans-resveratrol. The pure isomers were obtained by repeated column chromatography in various isolated yields depending on the heteroaromatic ring. It was found that butyrylcholinesterase (BChE) was more sensitive to the heteroaromatic resveratrol analogs than acetylcholinesterase (AChE), except for 6, the methylated thiophene derivative with chlorine, which showed equal inhibition toward both enzymes. Compounds 5 and 8 achieved the highest BChE inhibition with IC50 values of 22.9 and 24.8 µM, respectively. The same as with AChE and BChE, methylated thiophene subunits of resveratrol analogs showed better enzyme inhibition than unmethylated ones. Two antioxidant spectrophotometric methods, DPPH and CUPRAC, were applied to determine the antioxidant potential of new heteroaromatic resveratrol analogs. The molecular docking of these compounds was conducted to visualize the ligand-active site complexes' structure and identify the non-covalent interactions responsible for the complex's stability, which influence the inhibitory potential. As ADME properties are crucial in developing drug product formulations, they have also been addressed in this work. The potential genotoxicity is evaluated by in silico studies for all compounds synthesized.