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1.
Int J Mol Sci ; 25(7)2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38612942

RESUMO

Excessive and uncontrolled consumption of alcohol can cause alcohol use disorder (AUD), but its pharmacological mechanisms are not fully understood. Inhibiting the reverse mode activity of the sodium-calcium exchanger (NCX) can reduce the risk of alcohol withdrawal seizures, suggesting that NCX could play a role in controlling alcohol consumption. Here, we investigated how two potent inhibitors of NCX reverse mode activity, SN-6 (NCX1) and KB-R7943 (NCX3), affect voluntary alcohol consumption in adult male and female rats using the intermittent alcohol access two-bottle choice paradigm. Initially, animals were trained to drink 7.5% ethanol and water for four weeks before administering SN-6 and KB-R7934. Afterward, their alcohol intake, preference, and water intake were recorded 2 and 24 h after exposure to water and 7.5% ethanol. SN-6 significantly reduced alcohol consumption by 48% in male and 36% in female rats without affecting their water intake. Additionally, SN-6 significantly reduced alcohol preference in females by 27%. However, KB-R7943 reduced alcohol consumption by 42% in female rats and did not affect alcohol preference or water intake. These findings suggest that alcohol exposure increased NCX reverse activity, and targeting NCX1 could be an effective strategy for reducing alcohol consumption in subjects susceptible to withdrawal seizures.


Assuntos
Alcoolismo , Síndrome de Abstinência a Substâncias , Tioureia/análogos & derivados , Humanos , Adulto , Feminino , Masculino , Animais , Ratos , Trocador de Sódio e Cálcio , Consumo de Bebidas Alcoólicas , Etanol , Água
2.
Molecules ; 29(7)2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38611717

RESUMO

In the present work, the synthesis of new ethacrynic acid (EA) derivatives containing nitrogen heterocyclic, urea, or thiourea moieties via efficient and practical synthetic procedures was reported. The synthesised compounds were screened for their anti-proliferative activity against two different cancer cell lines, namely, HL60 (promyelocytic leukaemia) and HCT116 (human colon carcinoma). The results of the in vitro tests reveal that compounds 1-3, 10, 16(a-c), and 17 exhibit potent anti-proliferative activity against the HL60 cell line, with values of the percentage of cell viability ranging from 20 to 35% at 1 µM of the drug and IC50 values between 2.37 µM and 0.86 µM. Compounds 2 and 10 showed a very interesting anti-proliferative activity of 28 and 48% at 1 µM, respectively, against HCT116. Two PyTAP-based fluorescent EA analogues were also synthesised and tested, showing good anti-proliferative activity. A test on the drug-likeness properties in silico of all the synthetised compounds was performed in order to understand the mechanism of action of the most active compounds. A molecular docking study was conducted on two human proteins, namely, glutathione S-transferase P1-1 (pdb:2GSS) and caspase-3 (pdb:4AU8) as target enzymes. The docking results show that compounds 2 and 3 exhibit significant binding modes with these enzymes. This finding provides a potential strategy towards developing anticancer agents, and most of the synthesised and newly designed compounds show good drug-like properties.


Assuntos
Antineoplásicos , Ureia , Humanos , Tioureia/farmacologia , Ácido Etacrínico , Simulação de Acoplamento Molecular , Antineoplásicos/farmacologia , Células HL-60 , Nitrogênio
3.
Nat Commun ; 15(1): 2493, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38509098

RESUMO

The histamine H4 receptor (H4R) plays key role in immune cell function and is a highly valued target for treating allergic and inflammatory diseases. However, structural information of H4R remains elusive. Here, we report four cryo-EM structures of H4R/Gi complexes, with either histamine or synthetic agonists clobenpropit, VUF6884 and clozapine bound. Combined with mutagenesis, ligand binding and functional assays, the structural data reveal a distinct ligand binding mode where D943.32 and a π-π network determine the orientation of the positively charged group of ligands, while E1825.46, located at the opposite end of the ligand binding pocket, plays a key role in regulating receptor activity. The structural insight into H4R ligand binding allows us to identify mutants at E1825.46 for which the agonist clobenpropit acts as an inverse agonist and to correctly predict inverse agonism of a closely related analog with nanomolar potency. Together with the findings regarding receptor activation and Gi engagement, we establish a framework for understanding H4R signaling and provide a rational basis for designing novel antihistamines targeting H4R.


Assuntos
Agonismo Inverso de Drogas , Histamina , Imidazóis , Tioureia/análogos & derivados , Histamina/metabolismo , Receptores Histamínicos H4 , Receptores Acoplados a Proteínas G/metabolismo , Ligantes , Receptores Histamínicos/metabolismo , Antagonistas dos Receptores Histamínicos/farmacologia
4.
J Agric Food Chem ; 72(14): 7727-7734, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38530940

RESUMO

To discover novel transketolase (TKL, EC 2.2.1.1) inhibitors with potential herbicidal applications, a series of pyrazole acyl thiourea derivatives were designed based on a previously obtained pyrazolamide acyl lead compound, employing a scaffold hopping strategy. The compounds were synthesized, their structures were characterized, and they were evaluated for herbicidal activities. The results indicate that 7a exhibited exceptional herbicidal activity against Digitaria sanguinalis and Amaranthus retroflexus at a dosage of 90 g ai/ha, using the foliar spray method in a greenhouse. This performance is comparable to that of commercial products, such as nicosulfuron and mesotrione. Moreover, 7a showed moderate growth inhibitory activity against the young root and stem of A. retroflexus at 200 mg/L in the small cup method, similar to that of nicosulfuron and mesotrione. Subsequent mode-of-action verification experiments revealed that 7a and 7e inhibited Setaria viridis TKL (SvTKL) enzyme activity, with IC50 values of 0.740 and 0.474 mg/L, respectively. Furthermore, they exhibited inhibitory effects on the Brassica napus acetohydroxyacid synthase enzyme activity. Molecular docking predicted potential interactions between these (7a and 7e) and SvTKL. A greenhouse experiment demonstrated that 7a exhibited favorable crop safety at 150 g ai/ha. Therefore, 7a is a promising herbicidal candidate that is worthy of further development.


Assuntos
Cicloexanonas , Herbicidas , Piridinas , Compostos de Sulfonilureia , Herbicidas/farmacologia , Herbicidas/química , Relação Estrutura-Atividade , Simulação de Acoplamento Molecular , Esqueleto , Pirazóis/farmacologia , Pirazóis/química , Tioureia
5.
Chirality ; 36(3): e23659, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38445305

RESUMO

Due to a great demand for amylose and cellulose polymeric chromatographic chiral columns, the enantiomeric separation of thiourea derivatives of naringenin was achieved on the different amylose (Chiralpak-IB) and cellulose chiral (Chiralcel-OJ and Chiralcel-OD-3R) columns with varied chromatographic conditions. The isocratic mobile phases used were ethanol and methanol, where ethanol/hexane and methanol/hexane were used as gradient mode and were prepared in volume/volume relation. The separation and resolution factors for all the enantiomers were in the range of 1.25 to 3.47 and 0.48 to 1.75, respectively. The enantiomeric resolution was obtained within 12 min making fast separation. The docking studies confirmed the chiral recognition mechanisms with binding affinities in the range of -4.7 to -5.7 kcal/mol. The reported compounds have good anticoagulant activities and may be used as anticoagulants in the future. Besides, chiral separation is fast and is useful for enantiomeric separation in any laboratory in the world.


Assuntos
Amilose , Flavanonas , Hexanos , Metanol , Estereoisomerismo , Celulose , Polímeros , Etanol , Tioureia
6.
Nat Commun ; 15(1): 2101, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38453892

RESUMO

The architectural design of polycyclic/multisubstituted pentafulvenes has demonstrated great potential for the development of electrochromic materials and biologically active motifs. Unfortunately, the enantioselective construction of such distinctive cores with all carbon quaternary chiral centers has remained untouched to date. Herein, we disclose an enantioselective homologating annulation of cyclopent-4-ene-dione with 3-cyano-4-methylcoumarins through L-tert-leucine derived thiourea catalysis, affording a wide range of enantioenriched polycyclic multisubstituted embedded aminopentafulvenes with excellent stereocontrol (up to 99:1 er) and chemical yields up to 87%. A detailed photophysical and cytotoxicity analysis of racemic and chiral homologated adducts unveils the exceptional behavior of chiral adducts over their racemic analogs, highlighting the importance of stereoselectivity of the developed scaffolds. A cellular uptake experiment in a mammalian fibroblast cell line confirmed the potential of developed polycyclic aminopentafulvene cores as a highly promising labeling dye that can be utilized for bioimaging without any adverse effects.


Assuntos
Tioureia , Estereoisomerismo , Catálise
7.
J Mol Graph Model ; 129: 108760, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38513601

RESUMO

A new iminophosphorane-thiourea superbase was rationally designed and investigated as an organocatalyst for the enantioselective Michael addition reaction of nitromethane to 4-phenylbut-3-en-2-one. Starting from an iminophosphorane-thiourea organocatalyst structure already known, we have used theoretical calculations to determine the structures of transition states involved in the carbon-carbon bond formation step and carried out structural modifications to accelerate the reaction rate and to increase the enantioselectivity. The effective structural modification was adding a rigid hydroxyl group able to make an additional hydrogen bond to the transition state, producing a substantial decrease of the ΔG‡ by 7 kcal mol-1. The enantiomeric excess is predicted to be above of 97% using the reliable M06-2X and ωB97M - V functionals. The determination of the complete reaction mechanism and free energy profile was followed by a detailed microkinetic analysis. The present study points out a new direction for structural modifications on this kind of organocatalyst.


Assuntos
Carbono , Tioureia , Ligação de Hidrogênio , Catálise , Estereoisomerismo , Tioureia/química
8.
Int J Biol Macromol ; 263(Pt 1): 130231, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38368975

RESUMO

Three newly synthesized amantadine thiourea conjugates namely MS-1 N-(((3 s,5 s,7 s)-adamantan-1-yl)carbamothioyl)benzamide, MS-2 N-(((3 s,5 s,7 s)-adamantan-1-yl)carbamothioyl)-4-methylbenzamide and MS-3 N-((3 s,5 s,7 s)-adamantan-1-ylcarbamothioyl)-4-chlorobenzamide were investigated for their structures, bindings (DNA/ elastase), and for their impact on healthy and cancerous cells. Theoretical (DFT/docking) and experimental {UV-visible (UV-), fluorescence (Flu-), and cyclic voltammetry (CV)} studies indicated binding interactions of each conjugate with DNA and elastase enzyme. Theoretically and experimentally calculated binding parameters for conjugate - DNA interaction revealed MS-3 - DNA to have most significant binding with comparatively greater values of binding parameters {(Kb/M-1: docking, 3.8 × 105; UV-, 5.95 × 103; Flu-,1.55 × 105; CV, 1.52 × 104), (∆G/ kJmol-1: docking, -32.09; UV-, -22.40; Flu-,-30.81; CV, -24.82)}. The docked structures, greater bindings site size values (n), and the trend in DNA viscosity changes in the presence of each conjugate concentration confirmed a mixed binding mode of interaction among them. Conjugate - elastase binding by docking agreed with the experimental anti-elastase findings. Cytotoxicity studies of each tested conjugate demonstrated greater cytotoxicity for cancerous (MG-U87) cells in comparison to control, while for the normal (HEK-293) cells the cytotoxicity was found comparatively low. Overall exploration suggested that MS-3 is the most effective candidate for DNA binding, anti-elastase, and for anti-glioma activities.


Assuntos
Amantadina , Tioureia , Humanos , Tioureia/farmacologia , Tioureia/química , Células HEK293 , Simulação de Acoplamento Molecular , Amantadina/farmacologia , DNA/química , Elastase Pancreática
9.
PLoS One ; 19(2): e0292190, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38359044

RESUMO

Amyotrophic lateral sclerosis (ALS) has been linked to overactivity of the protein kinase RNA-like ER kinase (PERK) branch of the unfolded protein response (UPR) pathway, both in ALS patients and mouse models. However, attempts to pharmacologically modulate PERK for therapeutic benefit have yielded inconsistent and often conflicting results. This study sought to address these discrepancies by comprehensively evaluating three commonly used, CNS-penetrant, PERK modulators (GSK2606414, salubrinal, and Sephin1) in the same experimental models, with the goal of assessing the viability of targeting the PERK pathway as a therapeutic strategy for ALS. To achieve this goal, a tunicamycin-challenge assay was developed using wild-type mice to monitor changes in liver UPR gene expression in response to PERK pathway modulation. Subsequently, multiple dosing regimens of each PERK modulator were tested in standardized, well-powered, gender-matched, and litter-matched survival efficacy studies using the SOD1G93A mouse model of ALS. The alpha-2-adrenergic receptor agonist clonidine was also tested to elucidate the results obtained from the Sephin1, and of the previously reported guanabenz studies, by comparing the effects of presence or absence of α-2 agonism. The results revealed that targeting PERK may not be an ideal approach for ALS treatment. Inhibiting PERK with GSK2606414 or activating it with salubrinal did not confer therapeutic benefits. While Sephin1 showed some promising therapeutic effects, it appears that these outcomes were mediated through PERK-independent mechanisms. Clonidine also produced some favorable therapeutic effects, which were unexpected and not linked to the UPR. In conclusion, this study highlights the challenges of pharmacologically targeting PERK for therapeutic purposes in the SOD1G93A mouse model and suggests that exploring other targets within, and outside, the UPR may be more promising avenues for ALS treatment.


Assuntos
Adenina/análogos & derivados , Esclerose Amiotrófica Lateral , Cinamatos , Guanabenzo , Guanabenzo/análogos & derivados , Indóis , Tioureia/análogos & derivados , Camundongos , Humanos , Animais , Guanabenzo/farmacologia , Guanabenzo/uso terapêutico , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismo , Esclerose Amiotrófica Lateral/tratamento farmacológico , Esclerose Amiotrófica Lateral/genética , Clonidina , Resposta a Proteínas não Dobradas , Agonistas de Receptores Adrenérgicos alfa 2
10.
Drug Dev Res ; 85(1): e22143, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38349267

RESUMO

The effectiveness of a new series of thiopyrimidine and thiourea containing sulfonamides moieties was tested on HCT-116, MCF-7, HepG2, and A549. HepG2 cell line was the one that all the new derivatives affected the most. The greatest potent compounds against the four HepG2, HCT116, MCF-7, and A549 cell lines were 8f and 8g with IC50 = 4.13, 6.64, 5.74, 6.85 µM and 4.09, 4.36, 4.22, 7.25 µM correspondingly. Compound 8g exhibited higher activity than sorafenib against HCT116 and MCF-7 but exhibited lower activity against HepG2 and A549. Moreover, compounds 8f and 8g exhibited higher activities than erlotinib on HepG2, HCT116, and MCF-7 but demonstrated lower activity on A549. The most potent cytotoxic derivatives 6f, 6g, 8c, 8d, 8e, 8f, and 8g were examined on normal VERO cell lines. Our derivatives have low toxicity on VERO cells with IC50 values ranging from 32.05 to 53.15 µM. Additionally, all compounds were assessed for dual VEGFR-2 and EGFRT790M inhibition effects. Compounds 8f and 8g were the most potent derivatives inhibited VEGFR-2 at IC50 value of 0.88 and 0.90 µM, correspondingly. As well, derivatives 8f and 8g could inhibit EGFRT790M demonstrating strongest effects with IC50 = 0.32 and 0.33 µM sequentially. Additionally, the greatest active derivatives ADMET profile was evaluated in relationship with sorafenib and erlotinib as reference agents. The data attained from docking were greatly related to that achieved from the biological testing.


Assuntos
Neoplasias Pulmonares , Tioureia , Chlorocebus aethiops , Animais , Tioureia/farmacologia , Receptores ErbB , Cloridrato de Erlotinib , Sorafenibe , Receptor 2 de Fatores de Crescimento do Endotélio Vascular , Células Vero , Mutação , Inibidores de Proteínas Quinases/farmacologia , Sulfanilamida
11.
Future Med Chem ; 16(6): 497-511, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38372209

RESUMO

Background: Unsymmetrical thioureas 1-20 were synthesized and then characterized by various spectroscopy techniques such as UV, IR, fast atom bombardment (FAB)-MS, high-resolution FAB-MS, 1H-NMR and 13C-NMR. Methods: Synthetic compounds 1-20 were tested for their ability for antioxidant, lipoxygenase and xanthine oxidase activities. Results: Compounds 1, 2, 9, 12 and 15 exhibited strong antioxidant potential, whereas compounds 1-3, 9, 12, 15 and 19 showed good to moderate lipoxygenase activity. Ten compounds demonstrated moderate xanthine oxidase inhibition. Conclusion: Compound 15 displayed the highest potency among the series, exhibiting good antioxidant, lipoxygenase and xanthine oxidase activities. Theoretical calculations using density functional theory and molecular docking studies supported the experimental findings, indicating the potential of the synthesized compounds as potent antioxidants, lipoxygenases and xanthine oxidase agents.


Assuntos
Antioxidantes , Lipoxigenase , Antioxidantes/química , Simulação de Acoplamento Molecular , Xantina Oxidase/química , Xantina Oxidase/metabolismo , Inibidores Enzimáticos/química , Tioureia/farmacologia , Tioureia/química , Relação Estrutura-Atividade
12.
Inhal Toxicol ; 36(1): 31-43, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38261520

RESUMO

BACKGROUND: Lysosomal ion channels are proposed therapeutic targets for a number of diseases, including those driven by NLRP3 inflammasome-mediated inflammation. Here, the specific role of the lysosomal big conductance Ca2+-activated K+ (BK) channel was evaluated in a silica model of inflammation in murine macrophages. A specific-inhibitor of BK channel function, paxilline (PAX), and activators NS11021 and NS1619 were utilized to evaluate the role of lysosomal BK channel activity in silica-induced lysosomal membrane permeabilization (LMP) and NLRP3 inflammasome activation resulting in IL-1ß release. METHODS: Murine macrophages were exposed in vitro to crystalline silica following pretreatment with BK channel inhibitors or activators and LMP, cell death, and IL-1ß release were assessed. In addition, the effect of PAX treatment on silica-induced cytosolic K+ decrease was measured. Finally, the effects of BK channel modifiers on lysosomal pH, proteolytic activity, and cholesterol transport were also evaluated. RESULTS: PAX pretreatment significantly attenuated silica-induced cell death and IL-1ß release. PAX caused an increase in lysosomal pH and decrease in lysosomal proteolytic activity. PAX also caused a significant accumulation of lysosomal cholesterol. BK channel activators NS11021 and NS1619 increased silica-induced cell death and IL-1ß release. BK channel activation also caused a decrease in lysosomal pH and increase in lysosomal proteolytic function as well as a decrease in cholesterol accumulation. CONCLUSION: Taken together, these results demonstrate that inhibiting lysosomal BK channel activity with PAX effectively reduced silica-induced cell death and IL-1ß release. Blocking cytosolic K+ entry into the lysosome prevented LMP through the decrease of lysosomal acidification and proteolytic function and increase in lysosomal cholesterol.


Assuntos
Canais de Potássio Ativados por Cálcio de Condutância Alta , Proteína 3 que Contém Domínio de Pirina da Família NLR , Tetrazóis , Tioureia/análogos & derivados , Camundongos , Animais , Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Dióxido de Silício/metabolismo , Inflamassomos/metabolismo , Inflamação/induzido quimicamente , Inflamação/metabolismo , Lisossomos/metabolismo , Macrófagos/metabolismo , Colesterol
13.
Plant Physiol Biochem ; 207: 108320, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38183901

RESUMO

Water stress (WS) poses a significant threat to global food and energy security by adversely affecting soybean growth and nitrogen metabolism. This study explores the synergistic effects of exogenous salicylic acid (SA, 0.5 mM) and thiourea (TU, 400 mg L-1), potent plant growth regulators, on soybean responses under WS conditions. The treatments involved foliar spraying for 3 days before inducing WS by reducing soil moisture to 50% of field capacity, followed by 2 weeks of cultivation under normal or WS conditions. WS significantly reduced plant biomass, chlorophyll content, photosynthetic efficiency, water status, protein content, and total nitrogen content in roots and leaves. Concurrently, it elevated levels of leaf malondialdehyde, H2O2, proline, nitrate, and ammonium. WS also triggered an increase in antioxidant enzyme activity and osmolyte accumulation in soybean plants. Application of SA and TU enhanced the activities of key enzymes crucial for nitrogen assimilation and amino acid synthesis. Moreover, SA and TU improved plant growth, water status, chlorophyll content, photosynthetic efficiency, protein content, and total nitrogen content, while reducing oxidative stress and leaf proline levels. Indeed, the simultaneous application of SA and TU demonstrated a heightened impact compared to their separate use, suggesting a synergistic interaction. This study underscores the potential of SA and TU to enhance WS tolerance in soybean plants by modulating nitrogen metabolism and mitigating oxidative damage. These findings hold significant promise for improving crop productivity and quality in the face of escalating water limitations due to climate change.


Assuntos
Antioxidantes , Nitrogênio , Antioxidantes/metabolismo , Soja , Desidratação , Ácido Salicílico/farmacologia , Ácido Salicílico/metabolismo , Tioureia/farmacologia , Peróxido de Hidrogênio/metabolismo , Clorofila/metabolismo , Plantas/metabolismo , Prolina/metabolismo
14.
Am J Physiol Cell Physiol ; 326(3): C905-C916, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38223930

RESUMO

We studied urea, thiourea, and methylurea transport and interaction in human red blood cells (RBCs) under conditions of self-exchange (SE), net efflux (NE), and net influx (NI) at pH 7.2. We combined four methods, a four-centrifuge technique, the Millipore-Swinnex filtering technique, the continuous flow tube method, and a continuous pump method to measure the transport of the 14C-labeled compounds. Under SE conditions, both urea and thiourea show perfect Michaelis-Menten kinetics with half-saturation constants, K½,SE (mM), of ≈300 (urea) and ≈20 (thiourea). The solutes show no concentration-dependent saturation under NE conditions. Under NI conditions, transport displays saturation or self-inhibition kinetics with a K½,NI (mM) of ≈210 (urea) and ≈20 (thiourea). Urea, thiourea, and methylurea are competitive inhibitors of the transport of analog solutes. This study supports the hypothesis that the three compounds share the same urea transport system (UT-B). UT-B functions asymmetrically as it saturates from the outside only under SE and NI conditions, whereas it functions as a high-capacity channel-like transporter under NE conditions. When the red blood cell enters the urea-rich kidney tissue, self-inhibition reduces the urea uptake in the cell. When the cell leaves the kidney, the channel-like function of UT-B implies that intracellular urea rapidly equilibrates with external urea. The net result is that the cell during the passage in the kidney capillaries carries urea to the kidney to be excreted while the urea transfer from the kidney via the bloodstream is minimized.NEW & NOTEWORTHY The kinetics of urea transport in red blood cells was determined by means of a combination of four methods that ensures a high time resolution. In the present study, we disclose that the urea transporter UT-B functions highly asymmetric being channel-like with no saturation under conditions of net efflux and saturable under conditions of net influx and self-exchange in the concentration range 1-1,000 mM (pH 7.2 and 25-38 °C).


Assuntos
Compostos de Metilureia , 60540 , Ureia , Humanos , Tioureia/farmacologia , Eritrócitos
15.
J Chromatogr A ; 1717: 464683, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38295741

RESUMO

The complex and cumbersome preparation of magnetic covalent organic frameworks (COFs) nanocomposites on a small scale limits their application. Herein, a rapid and easy route was employed for the preparation of magnetic thiourea-based COFs nanocomposites. COFs were coated on Fe3O4 nanoparticles at room temperature without a catalyst within approximately 30 min. This method is suitable for the large-scale preparation of magnetic adsorbent. Using the as-prepared magnetic adsorbent (Fe3O4@COF-TpTU), we developed a simple, efficient, and sensitive magnetic solid-phase extraction-high performance liquid chromatography-inductively coupled plasma-mass spectrometry (MSPE-HPLC-ICP-MS) for the enrichment and determination of mercury species, including Hg2+, methylmercury (MeHg), and ethylmercury (EtHg). The effects of the experimental parameters on the extraction efficiency, including solution pH, adsorption and desorption time, composition and volume of the elution solvent, salinity, coexisting ions, and dissolved organic matter, were comprehensively investigated. Under optimised conditions, the limits of detection in the developed method were 0.56, 0.34, and 0.47 ng L-1 with enrichment factors of 190, 195, and 180-fold for Hg2+, MeHg, and EtHg, respectively. The satisfactory spiked recoveries (97.0-103%) in real water samples and high consistency between the certified and determined values in a certified reference material demonstrate the high accuracy and reproducibility of the developed method. The as-proposed method with simple operation, high sensitivity, and excellent anti-matrix interference performance was successfully applied to the enrichment and determination of trace levels of mercury species in the natural samples with complicated matrices, such as underground water, surface water, seawater and biological samples.


Assuntos
Mercúrio , Estruturas Metalorgânicas , Compostos de Metilmercúrio , Mercúrio/análise , Estruturas Metalorgânicas/química , Cromatografia Líquida de Alta Pressão/métodos , Tioureia , Reprodutibilidade dos Testes , Temperatura , Compostos de Metilmercúrio/análise , Água/química , Fenômenos Magnéticos , Extração em Fase Sólida/métodos
16.
J Biomol Struct Dyn ; 42(2): 1047-1063, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37029768

RESUMO

Angiogenesis is mediated by the vascular endothelial growth factor (VEGF) that plays a key role in the modulation of progression, invasion and metastasis, related to solid tumors and hematological malignancies. Several small-molecule VEGFR-2 inhibitors are marketed, but their usage is restricted to specific cancers due to severe toxicities. Therefore, cost-effective novel small molecule VEGFR-2 inhibitors may be an alternative to overcome these adverse effects. Here, a set of thiourea-based VEGFR-2 inhibitors were considered for a combined fragment-based QSAR technique, structure-based molecular docking followed by molecular dynamics simulation studies to acquire insights into the key structural attributes and the binding pattern of enzyme-ligand interactions. Noticeably, amine-substituted quinazoline phenyl ring and a higher number of nitrogen atoms, and the hydrazide function in the molecular structure are crucial for VEGFR-2 inhibition whereas methoxy groups are detrimental to VEGFR-2 inhibition. The MD simulation study of sorafenib and thiourea derivatives explored the significance of urea and thiourea moiety binding at VEGFR-2 active site that can be utilized further in the future to design molecules for greater binding stability and better VEGFR-2 selectivity. Therefore, such findings can be beneficial for the development of newer VEGFR-2 inhibitors for further refinement to acquire better therapeutic efficacy.Communicated by Ramaswamy H. Sarma.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Simulação de Acoplamento Molecular , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Ligantes , Fator A de Crescimento do Endotélio Vascular , Estrutura Molecular , Simulação de Dinâmica Molecular , Neoplasias/tratamento farmacológico , Tioureia/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/química , Antineoplásicos/química , Proliferação de Células
17.
Anal Bioanal Chem ; 416(2): 431-438, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37982846

RESUMO

This study reports a novel analytical approach for the simultaneous determination of ethylene-thiourea (ETU) and propylene-thiourea (PTU) in fruits and vegetables by (reverse phase) high-performance liquid chromatography (HPLC) coupled to inductively coupled plasma-tandem mass spectrometry (ICP-QQQMS or ICP-MS/MS). A baseline separation of ETU and PTU was achieved in less than 5 min. A robust method validation by using the accuracy profile approach was performed by carrying out four measurement series in duplicate at six different levels over a timespan of 4 weeks (different days). The recovery factors ranged from 87 to 101% for ETU and from 98 to 99% for PTU (depending on the spiking level). The coefficient of variation in terms of repeatability (CVr) ranged from 1 to 4.7% for ETU and from 1.8 to 3.9% for PTU (depending also on the analyte level) while the coefficient of variation in terms of intermediate reproducibility (CVR) ranged from 3.4 to 10% for ETU and from 1.8 to 10.8% for PTU. The limit of quantification was 0.022 mg kg-1 (wet weight) for ETU and 0.010 mg kg-1 (ww) for PTU. This novel approach was proved to be highly robust and suitable for the determination of ETU and PTU in foodstuffs of vegetal origin.


Assuntos
Etilenotioureia , Tioureia , Tioureia/análise , Etilenotioureia/análise , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Reprodutibilidade dos Testes , Etilenos
18.
Naunyn Schmiedebergs Arch Pharmacol ; 397(1): 305-315, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37436497

RESUMO

Inhibition of Helicobacter pylori urease is an effective method in the treatment of several gastrointestinal diseases in humans. This bacterium plays an important role in the pathogenesis of gastritis and peptic ulceration. Considering the presence of cysteine and N-arylacetamide derivatives in potent urease inhibitors, here, we designed hybrid derivatives of these pharmacophores. Therefore, cysteine-N-arylacetamide derivatives 5a-l were synthesized through simple nucleophilic reactions with good yield. In vitro urease inhibitory activity assay of these compounds demonstrated that all newly synthesized compounds exhibited high inhibitory activity (IC50 values = 0.35-5.83 µM) when compared with standard drugs (thiourea: IC50 = 21.1 ± 0.11 µM and hydroxyurea: IC50 = 100.0 ± 0.01 µM). Representatively, compound 5e with IC50 = 0.35 µM was 60 times more potent than strong urease inhibitor thiourea. Enzyme kinetic study of this compound revealed that compound 5e is a competitive urease inhibitor. Moreover, a docking study of compound 5e was performed to explore crucial interactions at the urease active site. This study revealed that compound 5e is capable to inhibit urease by interactions with two crucial residues at the active site: Ni and CME592. Furthermore, a molecular dynamics study confirmed the stability of the 5e-urease complex and Ni chelating properties of this compound. It should be considered that, in the following study, the focus was placed on jack bean urease instead of H. pylori urease, and this was acknowledged as a limitation.


Assuntos
Helicobacter pylori , Urease , Humanos , Urease/química , Urease/metabolismo , Cisteína/farmacologia , Simulação de Acoplamento Molecular , Helicobacter pylori/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Tioureia/química , Tioureia/farmacologia , Relação Estrutura-Atividade
19.
Bioorg Chem ; 143: 107022, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38142558

RESUMO

Liver fibrosis remains a global health challenge due to its rapidly rising prevalence and limited treatment options. The orphan nuclear receptor Nur77 has been implicated in regulation of autophagy and liver fibrosis. Targeting Nur77-mediated autophagic flux may thus be a new promising strategy against hepatic fibrosis. In this study, we synthesized four types of Nur77-based thiourea derivatives to determine their anti-hepatic fibrosis activity. Among the synthesized thiourea derivatives, 9e was the most potent inhibitor of hepatic stellate cells (HSCs) proliferation and activation. This compound could directly bind to Nur77 and inhibit TGF-ß1-induced α-SMA and COLA1 expression in a Nur77-dependent manner. In vivo, 9e significantly reduced CCl4-mediated hepatic inflammation response and extracellular matrix (ECM) production, revealing that 9e is capable of blocking the progression of hepatic fibrosis. Mechanistically, 9e induced Nur77 expression and enhanced autophagic flux by inhibiting the mTORC1 signaling pathway in vitro and in vivo. Thus, the Nur77-targeted lead 9e may serve as a promising candidate for treatment of chronic liver fibrosis.


Assuntos
Antifibróticos , Tiossemicarbazonas , Humanos , Tiossemicarbazonas/metabolismo , Células Estreladas do Fígado , Fígado/metabolismo , Cirrose Hepática/metabolismo , Tioureia/metabolismo , Tetracloreto de Carbono
20.
Chemosphere ; 350: 141013, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38145847

RESUMO

Photocatalysis has emerged as a highly effective method for eliminating organic pollutants from wastewater. The immobilization of photocatalysts on a suitable solid surface is highly desired to achieve enhanced photocatalytic activity. In this work, graphitic carbon nitride (g-C3N4) is synthesized with three different precursors (melamine, thiourea, and urea) via a simple thermal exfoliation method and successfully immobilized on a polyurethane (PU) foam using the facile dip coating method. The photocatalytic activity of g-C3N4 bulk and g-C3N4 nanosheets-coated PU foams are compared using methyl orange dye and tetracycline hydrochloride as a test pollutant under visible light irradiation. Our results show that the type of precursors and surface area of the sample have a significant role in photocatalytic dye degradation. The urea-based g-C3N4 - PU foam shows better photocatalytic activity than the melamine or thiourea based g-C3N4 - PU foam. The scavenger test unveils that superoxide radical (O2●-) and holes (h+) are the main reactive oxidative species responsible for MO dye and TcH degradations. The cycling experiments are also carried out to confirm the reusability of the g-C3N4 floating catalyst for practical applications. Furthermore, a possible reaction mechanism has also been proposed.


Assuntos
Poluentes Ambientais , Poliuretanos , Luz , Ureia , Tioureia
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