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1.
Anticancer Res ; 40(10): 5427-5436, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988864

RESUMO

BACKGROUND/AIM: The tetrazolium-based MTT cytotoxicity assay is well established for screening putative anti-cancer agents. However, it has limitations including lack of reproducibility with glioma cells treated with polyphenols. The aim of this study was to evaluate whether a flow cytometric assay with the anthraquinone, DRAQ7, was a better alternative than the colorimetric MTT assay for measuring cell viability. MATERIALS AND METHODS: Two glioma cell lines (IPSB-18, U373) and 1 pancreatic cancer cell line (AsPC-1) were treated with 4 polyphenols, namely red grape seed extract, red clover extract, anthocyanin-rich extract and curcumin. Cell viability was assessed using MTT assay and DRAQ7 staining. RESULTS: Limitations of MTT assay included lack of sensitivity and interference with the structure and absorbance spectra of polyphenols. Also, DMSO was toxic to glioma cells. Microscopic observations of cells treated with polyphenols confirmed the range of IC50 values evaluated by DRAQ7, but not by the MTT assay. CONCLUSION: DRAQ7 is a better alternative than MTT for measuring viability of glioma cells treated with brightly coloured polyphenols.


Assuntos
Antraciclinas/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Glioma/tratamento farmacológico , Polifenóis/farmacologia , Antraciclinas/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Glioma/patologia , Humanos , Concentração Inibidora 50 , Sais de Tetrazólio/química , Tiazóis/química
2.
Life Sci ; 258: 118179, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32758626

RESUMO

OBJECTIVE: To evaluate whether approved gastroprokinetic agent, acotiamide exerts a direct excitatory effect on bladder to help explain the reported meaningful reduction of post-void residual urine volume (PVR) in detrusor underactivity (DU) patients after thrice daily oral intake of acotiamide 100 mg for 2 weeks. METHODS: Effect of acotiamide [1-16 µM] was assessed on nerve-mediated contractions evoked by electrical field stimulation (EFS) for 5 s with 5 ms pulse trains of 10 V in longitudinal, mucosa intact rat and human bladder strips to construct frequency response curve (1-32 Hz) and repeat 10 Hz stimulation at 60s interval. Effect of acotiamide 2 µM on spontaneous and carbachol evoked contractions was also assessed. RESULTS: Acotiamide 2 µM significantly enhanced the Atropine and Tetrodotoxin (TTX)-sensitive EFS evoked contractions of rat and human bladder at 8-32 Hz (Two-way ANOVA followed Sidak's multiple comparison; *p < 0.01) and on repeat 10 Hz stimulation (Paired Student's t-test; *p < 0.05), while producing a modest effect on the spontaneous contractions and a negligible effect on the carbachol evoked contractions. CONCLUSIONS: Enhancement of TTX-sensitive evoked contractions of rat and human bladder by acotiamide is consistent with the enhancement of excitatory neuro-effector transmission mainly through prejunctional mechanisms. Findings highlight immense therapeutic potential of antimuscarinics with low M3 receptor affinity like acotiamide in Underactive bladder (UAB)/DU treatment.


Assuntos
Benzamidas/uso terapêutico , Tiazóis/uso terapêutico , Bexiga Inativa/tratamento farmacológico , Bexiga Urinária/patologia , Animais , Benzamidas/química , Benzamidas/farmacologia , Carbacol/farmacologia , Estimulação Elétrica , Humanos , Masculino , Contração Muscular/efeitos dos fármacos , Ratos Sprague-Dawley , Tiazóis/química , Tiazóis/farmacologia , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/inervação
3.
Chem Biol Interact ; 330: 109244, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32861748

RESUMO

The 2-aminothiazole functionality has long been established as a privileged structural feature and therefore frequently exploited in the process of drug discovery and development. It has been introduced into numerous compounds due to its capacity for targeting a wide range of therapeutic target proteins. On the other hand, the aminothiazole group has also been classified as a toxicophore susceptible to metabolic activation and the ensuing reactive metabolite formation, hence caution is warranted when used in drug design. This review is divided into three parts entailing: (i) the general characteristics of the aminothiazole group, (ii) the advantages of the aminothiazole group in medicinal chemistry, and (iii) the impact of the integrated aminothiazole group on compound safety profile.


Assuntos
Descoberta de Drogas/métodos , Tiazóis/química , Animais , Humanos , Relação Estrutura-Atividade , Tiazóis/metabolismo , Tiazóis/toxicidade
4.
Toxicol Appl Pharmacol ; 401: 115080, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32497533

RESUMO

Upregulation of ABCB1/MDR1 (P-gp) and BIRC5/Survivin promotes multidrug resistance in a variety of human cancers. LCL161 is an anti-cancer DIABLO/SMAC mimetic currently being tested in patients with solid tumors, but the molecular mechanism of action of LCL161 in cancer cells is still incompletely understood. It is still unclear whether LCL161 is therapeutically applicable for patients with ABCB1-overexpressing multidrug resistant tumors. In this study, we found that the potency of LCL161 is not affected by the expression of ABCB1 in KB-TAX50, KB-VIN10, and NTU0.017 cancer cells. Besides, LCL161 is equally potent towards the parental MCF7 breast cancer cells and its BIRC5 overexpressing, hormone therapy resistance subline MCF7-TamC3 in vitro. Mechanistically, we found that LCL161 directly modulates the ABCB1-ATPase activity and inhibits ABCB1 multi-drug efflux activity at low cytotoxic concentrations (i.e. 0.5xIC50 or less). Further analysis revealed that LCL161 also decreases intracellular ATP levels in part through BIRC5 downregulation. Therapeutically, co-treatment with LCL161 at low cytotoxic concentrations restored the sensitivity to the known ABCB1 substrate, paclitaxel, in ABCB1-expressing cancer cells and increased the sensitivity to tamoxifen in MCF7-TamC3 cells. In conclusion, LCL161 has the potential for use in the management of cancer patients with ABCB1 and BIRC5-related drug resistance. The findings of our study provide important information to physicians for designing a more "patient-specific" LCL161 clinical trial program in the future.


Assuntos
Adenosina Trifosfatases/antagonistas & inibidores , Antineoplásicos/farmacologia , Proteínas Reguladoras de Apoptose/farmacologia , Proteínas Mitocondriais/farmacologia , Survivina/antagonistas & inibidores , Tiazóis/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Adenosina Trifosfatases/metabolismo , Antineoplásicos/química , Proteínas Reguladoras de Apoptose/química , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Proteínas Mitocondriais/química , Estrutura Secundária de Proteína , Survivina/biossíntese , Survivina/genética , Tiazóis/química
5.
Nat Commun ; 11(1): 2272, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385237

RESUMO

Lactazole A is a cryptic thiopeptide from Streptomyces lactacystinaeus, encoded by a compact 9.8 kb biosynthetic gene cluster. Here, we establish a platform for in vitro biosynthesis of lactazole A, referred to as the FIT-Laz system, via a combination of the flexible in vitro translation (FIT) system with recombinantly produced lactazole biosynthetic enzymes. Systematic dissection of lactazole biosynthesis reveals remarkable substrate tolerance of the biosynthetic enzymes and leads to the development of the minimal lactazole scaffold, a construct requiring only 6 post-translational modifications for macrocyclization. Efficient assembly of such minimal thiopeptides with FIT-Laz opens access to diverse lactazole analogs with 10 consecutive mutations, 14- to 62-membered macrocycles, and 18 amino acid-long tail regions, as well as to hybrid thiopeptides containing non-proteinogenic amino acids. This work suggests that the minimal lactazole scaffold is amenable to extensive bioengineering and opens possibilities to explore untapped chemical space of thiopeptides.


Assuntos
Bioengenharia , Peptídeos/metabolismo , Tiazóis/metabolismo , Sequência de Aminoácidos , Vias Biossintéticas , Código Genético , Peptídeos/química , Especificidade por Substrato , Tiazóis/química
6.
Biofouling ; 36(3): 351-367, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32401555

RESUMO

Pseudomonas aeruginosa and Serratia marcescens are prominent members belonging to the group of ESKAPE pathogens responsible for Urinary Tract Infections (UTI) and nosocomial infections. Both the pathogens regulate several virulence factors, including biofilm formation through quorum sensing (QS), an intercellular communication mechanism. The present study describes the anti-biofilm and QS quenching effect of thiazolinyl-picolinamide based palladium(II) complexes against P. aeruginosa and S. marcescens. Palladium(II) complexes showed quorum sensing inhibitory potential in inhibiting swarming motility behaviour, pyocyanin production and other QS mediated virulence factors in both P. aeruginosa and S. marcescens. In addition, the establishment of biofilms was prevented on palladium (II) coated catheters. Overall, the present study demonstrates that thiazolinyl-picolinamide based palladium (II) complexes will be a promising strategy to combat device-mediated UTI infections.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Paládio/farmacologia , Ácidos Picolínicos/química , Tiazóis/química , Cateteres Urinários/microbiologia , Antibacterianos/química , Antibacterianos/toxicidade , Biofilmes/crescimento & desenvolvimento , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/química , Complexos de Coordenação/toxicidade , Infecção Hospitalar/prevenção & controle , Humanos , Células MCF-7 , Paládio/química , Paládio/toxicidade , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/metabolismo , Piocianina/metabolismo , Percepção de Quorum/efeitos dos fármacos , Serratia marcescens/efeitos dos fármacos , Serratia marcescens/metabolismo , Infecções Urinárias/microbiologia , Infecções Urinárias/prevenção & controle , Virulência , Fatores de Virulência/metabolismo
7.
AAPS PharmSciTech ; 21(3): 115, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32296987

RESUMO

The objective of the current study was to develop ziprasidone hydrochloride monohydrate (ZHM) nanocrystal-based orally dispersible tablet (ODT) formulations. Design of experiment approach was used to develop ODTs. The tablets were compressed using direct compression method and characterized with quality control tests. In vitro dissolution studies and Caco-2 cell permeability tests were executed. The hardness and friability values of nanocrystal-based ODTs were found 31.2 N and 1.05%, respectively. The disintegration time was below 10 s. Dissolution profile in pH 7.4 phosphate buffer showed that nanocrystal-based ODTs and commercial product were dissolved in 120 min 58.98% and 16%, respectively. In pH 7.4 phosphate buffer with SLS, sample groups dissolved above 85% at the end of the study. Permeability value and cumulative ZHM amount on the cells were improved with nanocrystals. In conclusion, the novel formulation of ZHM nanocrystal-based ODTs was successfully developed for alternative dosage form.


Assuntos
Piperazinas/administração & dosagem , Tiazóis/administração & dosagem , Administração Oral , Células CACO-2 , Humanos , Concentração de Íons de Hidrogênio , Nanopartículas , Permeabilidade , Piperazinas/química , Solubilidade , Comprimidos , Tiazóis/química
8.
Phys Chem Chem Phys ; 22(9): 4957-4966, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32073078

RESUMO

We analyzed the near-degenerate states of the firefly dioxetanone anion (FDO-) and its prototypes, especially in the biradical region, using multi-configurational approaches. The importance of utilizing full valence active spaces by means of density-matrix renormalization group self-consistent field (DMRG-SCF) calculations was described. Our results revealed that the neglect of some valence orbitals can affect the quantitative accuracy in later multi-reference calculations or the qualitative conclusion when optimizing conical intersections. Using all of the relevant valence orbitals of FDO-, we confirmed that there were two conical intersections, as reported in previous work, and that the intersecting states were changed when the active space was enlarged. Beyond these, we found that there were strong interactions between states in the biradical regions, in which the changes in entanglements can be used to visualize the interacting state evolution.


Assuntos
Vaga-Lumes/química , Compostos Heterocíclicos com 1 Anel/química , Animais , Ânions/química , Vaga-Lumes/metabolismo , Luminescência , Teoria Quântica , Tiazóis/química
9.
Mem Inst Oswaldo Cruz ; 115: e190348, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049098

RESUMO

BACKGROUND: It was previously demonstrated that CMC-20, a nitazoxanide and N-methyl-1H-benzimidazole hybrid molecule, had higher in vitro activity against Giardia intestinalis WB strain than metronidazole and albendazole and similar to nitazoxanide. OBJETIVES: To evaluate the in vitro activity of CMC-20 against G. intestinalis strains with different susceptibility/resistance to albendazole and nitazoxanide and evaluate its effect on the distribution of parasite cytoskeletal proteins and its in vivo giardicidal activity. METHODS: CMC-20 activity was tested against two isolates from patients with chronic and acute giardiasis, an experimentally induced albendazole resistant strain and a nitazoxanide resistant clinical isolate. CMC-20 effect on the distribution of parasite cytoskeletal proteins was analysed by indirect immunofluorescence and its activity was evaluated in a murine model of giardiasis. FINDINGS CMC-20: showed broad activity against susceptible and resistant strains to albendazole and nitaxozanide. It affected the parasite microtubule reservoir and triggered the parasite encystation. In this process, alpha-7.2 giardin co-localised with CWP-1 protein. CMC-20 reduced the infection time and cyst load in feces of G. muris infected mice similar to albendazole. MAIN CONCLUSIONS: The in vitro and in vivo giardicidal activity of CMC-20 suggests its potential use in the treatment of giardiasis.


Assuntos
Albendazol/farmacologia , Antiprotozoários/farmacologia , Proteínas do Citoesqueleto/efeitos dos fármacos , Giardia lamblia/efeitos dos fármacos , Tiazóis/farmacologia , Albendazol/química , Animais , Antiprotozoários/química , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Camundongos , Testes de Sensibilidade Parasitária , Tiazóis/química , Fatores de Tempo
10.
RNA ; 26(5): 541-549, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32014999

RESUMO

The PI3K/Akt/mTOR kinase pathway is extensively deregulated in human cancers. One critical node under regulation of this signaling axis is eukaryotic initiation factor (eIF) 4F, a complex involved in the control of translation initiation rates. eIF4F-dependent addictions arise during tumor initiation and maintenance due to increased eIF4F activity-generally in response to elevated PI3K/Akt/mTOR signaling flux. There is thus much interest in exploring eIF4F as a small molecule target for the development of new anticancer drugs. The DEAD-box RNA helicase, eIF4A, is an essential subunit of eIF4F, and several potent small molecules (rocaglates, hippuristanol, pateamine A) affecting its activity have been identified and shown to demonstrate anticancer activity in vitro and in vivo in preclinical models. Recently, a number of new small molecules have been reported as having the capacity to target and inhibit eIF4A. Here, we undertook a comparative analysis of their biological activity and specificity relative to the eIF4A inhibitor, hippuristanol.


Assuntos
Antineoplásicos/química , Fator de Iniciação 4A em Eucariotos/química , Neoplasias/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/química , Esteróis/química , Antineoplásicos/farmacologia , Benzofuranos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Compostos de Epóxi/química , Fator de Iniciação 4A em Eucariotos/antagonistas & inibidores , Fator de Iniciação 4F em Eucariotos/antagonistas & inibidores , Fator de Iniciação 4F em Eucariotos/química , Humanos , Macrolídeos/química , Neoplasias/genética , Fosfatidilinositol 3-Quinases/genética , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/genética , Bibliotecas de Moléculas Pequenas/farmacologia , Esteróis/farmacologia , Serina-Treonina Quinases TOR/genética , Tiazóis/química
11.
J Enzyme Inhib Med Chem ; 35(1): 549-554, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31967484

RESUMO

A small series of 2,4-dioxothiazolidinyl acetic acids was prepared from thiourea, chloroacetic acid, aromatic aldehydes, and ethyl-2-bromoacetate. They were assayed for the inhibition of four physiologically relevant carbonic anhydrase (CA, EC 4.2.1.1) isoforms of human (h) origin, the cytosolic hCA I and II, and the transmembrane hCA IX and XII, involved among others in tumorigenesis (hCA IX and XII) and glaucoma (hCA II and XII). The two cytosolic isoforms were not inhibited by these carboxylates, which were also rather ineffective as hCA IX inhibitors. On the other hand, they showed submicromolar hCA XII inhibition, with KIs in the range of 0.30-0.93 µM, making them highly CA XII-selective inhibitors.


Assuntos
Acetatos/farmacologia , Anidrase Carbônica IX/antagonistas & inibidores , Inibidores da Anidrase Carbônica/classificação , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Tiazóis/farmacologia , Acetatos/síntese química , Acetatos/química , Antígenos de Neoplasias/metabolismo , Anidrase Carbônica IX/metabolismo , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/química
12.
J Med Chem ; 63(4): 1642-1659, 2020 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-31961685

RESUMO

Indoleamine 2,3-dioxygenase (IDO1) inhibitors are speculated to be useful in cancer immunotherapy, but a phase III clinical trial of the most advanced IDO1 inhibitor, epacadostat, did not meet its primary end point and was abandoned. In previous work, we identified the novel IDO1 inhibitor N-(4-chlorophenyl)-2-((5-phenylthiazolo[2,3-c][1,2,4]triazol-3-yl)thio)acetamide 1 through high-throughput screening (HTS). Herein, we report a structure-activity relationship (SAR) study of this compound, which resulted in the potent IDO1 inhibitor 1-(4-cyanophenyl)-3-(3-(cyclopropylethynyl)imidazo[2,1-b]thiazol-5-yl)thiourea 47 (hIDO IC50 = 16.4 nM). X-ray cocrystal structural analysis revealed that the basis for this high potency is a unique sulfur-aromatic interaction network formed by the thiourea moiety of 47 with F163 and F226. This finding is expected to inspire new approaches toward the discovery of potent IDO1 inhibitors in the future.


Assuntos
Inibidores Enzimáticos/química , Imidazóis/química , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Tiazóis/química , Sítios de Ligação , Cristalografia por Raios X , Descoberta de Drogas , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Humanos , Imidazóis/síntese química , Imidazóis/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/química , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Estrutura Molecular , Ligação Proteica , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/metabolismo
13.
PLoS One ; 15(1): e0227224, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31905374

RESUMO

The imidazo[2,1-b]thiazole-5-carboxamides (ITAs) are a promising class of anti-tuberculosis agents shown to have potent activity in vitro and to target QcrB, a key component of the mycobacterial cytochrome bcc-aa3 super complex critical for the electron transport chain. Herein we report the intracellular macrophage potency of nine diverse ITA analogs with MIC values ranging from 0.0625-2.5 µM and mono-drug resistant potency ranging from 0.0017 to 7 µM. The in vitro ADME properties (protein binding, CaCo-2, human microsomal stability and CYP450 inhibition) were determined for an outstanding compound of the series, ND-11543. ND-11543 was tolerable at >500 mg/kg in mice and at a dose of 200 mg/kg displayed good drug exposure in mice with an AUC(0-24h) >11,700 ng·hr/mL and a >24 hr half-life. Consistent with the phenotype observed with other QcrB inhibitors, compound ND-11543 showed efficacy in a chronic murine TB infection model when dosed at 200 mg/kg for 4 weeks. The efficacy was not dependent upon exposure, as pre-treatment with a known CYP450-inhibitor did not substantially improve efficacy. The ITAs are an interesting scaffold for the development of new anti-TB drugs especially in combination therapy based on their favorable properties and novel mechanism of action.


Assuntos
Antituberculosos/uso terapêutico , Imidazóis/uso terapêutico , Mycobacterium tuberculosis/efeitos dos fármacos , Tiazóis/uso terapêutico , Tuberculose/tratamento farmacológico , Animais , Antituberculosos/química , Antituberculosos/farmacologia , Células CACO-2 , Chlorocebus aethiops , Inibidores das Enzimas do Citocromo P-450/química , Inibidores das Enzimas do Citocromo P-450/farmacologia , Inibidores das Enzimas do Citocromo P-450/uso terapêutico , Humanos , Imidazóis/química , Imidazóis/farmacologia , Camundongos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/crescimento & desenvolvimento , Células RAW 264.7 , Tiazóis/química , Tiazóis/farmacologia , Células Vero
14.
Chem Rev ; 120(4): 1981-2048, 2020 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-31967451

RESUMO

In this contribution, we provide a comprehensive overview of C-H activation methods promoted by NHC-transition metal complexes, covering the literature since 2002 (the year of the first report on metal-NHC-catalyzed C-H activation) through June 2019, focusing on both NHC ligands and C-H activation methods. This review covers C-H activation reactions catalyzed by group 8 to 11 NHC-metal complexes. Through discussing the role of NHC ligands in promoting challenging C-H activation methods, the reader is provided with an overview of this important area and its crucial role in forging carbon-carbon and carbon-heteroatom bonds by directly engaging ubiquitous C-H bonds.


Assuntos
Técnicas de Química Sintética/métodos , Compostos Heterocíclicos/química , Metano/análogos & derivados , Compostos Organometálicos/química , Paládio/química , Compostos Heterocíclicos/síntese química , Imidazóis/química , Metano/química , Oxazóis/química , Tiazóis/química
15.
Org Biomol Chem ; 18(5): 931-940, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-31922157

RESUMO

The design of glycogen phosphorylase (GP) inhibitors targeting the catalytic site of the enzyme is a promising strategy for a better control of hyperglycaemia in the context of type 2 diabetes. Glucopyranosylidene-spiro-heterocycles have been demonstrated as potent GP inhibitors, and more specifically spiro-oxathiazoles. A new synthetic route has now been elaborated through 1,3-dipolar cycloaddition of an aryl nitrile oxide to a glucono-thionolactone affording in one step the spiro-oxathiazole moiety. The thionolactone was obtained from the thermal rearrangement of a thiosulfinate precursor according to Fairbanks' protocols, although with a revisited outcome and also rationalised with DFT calculations. The 2-naphthyl substituted glucose-based spiro-oxathiazole 5h, identified as one of the most potent GP inhibitors (Ki = 160 nM against RMGPb) could be produced on the gram-scale from this strategy. Further evaluation in vitro using rat and human hepatocytes demonstrated that compound 5h is a anti-hyperglycaemic drug candidates performing slightly better than DAB used as a positive control. Investigation in Zucker fa/fa rat model in acute and subchronic assays further confirmed the potency of compound 5h since it lowered blood glucose levels by ∼36% at 30 mg kg-1 and ∼43% at 60 mg kg-1. The present study is one of the few in vivo investigations for glucose-based GP inhibitors and provides data in animal models for such drug candidates.


Assuntos
Inibidores Enzimáticos/farmacologia , Glucose/metabolismo , Glicogênio Fosforilase/antagonistas & inibidores , Hipoglicemiantes/farmacologia , Compostos de Espiro/farmacologia , Tiazóis/farmacologia , Animais , Glicemia/metabolismo , Ciclização , Teoria da Densidade Funcional , Glicogênio/metabolismo , Glicogênio Fosforilase/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Hipoglicemiantes/síntese química , Hipoglicemiantes/química , Concentração Inibidora 50 , Cinética , Lactonas/síntese química , Lactonas/química , Oxirredução , Ratos Zucker , Compostos de Espiro/síntese química , Compostos de Espiro/química , Estereoisomerismo , Temperatura , Tiazóis/síntese química , Tiazóis/química
16.
Chem Biodivers ; 17(2): e1900577, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31823465

RESUMO

Organopromoter, 2-aminoethanesulfonic acid was used to catalyze the synthesis of a series of structurally intriguing new hybrids thiazolyl acridine-1,8(2H,5H)-diones and dihydropyrido[2,3-d : 6,5-d']dipyrimidine-2,4,6,8(1H,3H,5H,7H)-tetraones for the first time. 2-Aminoethanesulfonic acid is a biobased organopromoter, used to generate four new bonds for the synthesis of new coupled thiazole-based decahydroacridine-1,8-diones. Superior green credentials, operational simplicity, easy work-up and recyclability of the catalyst are the key strengths of this method. The broad substrate scope, mild reaction conditions, short reaction time, cost effectiveness, high atom economy and good to excellent yields make the present method a distinct improvement over existing methods. Spectral (IR, 1 H-NMR,13 C-NMR, Mass) data and elemental analyses confirmed the structures of the titled products. A series of thiazolyl acridine-1,8(2H,5H)-diones and dihydropyrido[2,3-d : 6,5-d']dipyrimidine-2,4,6,8(1H,3H,5H,7H)-tetraones were screened for their antimicrobial activity against four bacterial and three fungal strains.


Assuntos
Acridinas/química , Anti-Infecciosos/síntese química , Piridinas/química , Ácidos Sulfônicos/química , Tiazóis/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Aspergillus/efeitos dos fármacos , Candida/efeitos dos fármacos , Catálise , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Água/química
17.
Biomed Chromatogr ; 34(2): e4716, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31633824

RESUMO

Tizoxanide, the active metabolite of nitazoxanide, has recently been reported as an effective agent for the treatment of glioma. As there had been no report about the analysis of tizoxanide in brain tissue, we established extraction and UHPLC-MS/MS methods to quantify tizoxanide in rat brain and plasma to evaluate the brain-to-plasma ratio of tizoxanide. The biological samples were mainly prepared by acetonitrile and the separation was performed on a Waters XBridge® BEH C18 column. The mobile phase was composed of water mixed with 10 mm ammonium formate (pH 3.0) and acetonitrile according a gradient volume. Tizoxanide and topiramate (internal standard) were monitored utilizing negative electron spray ionization in multiple reaction monitoring mode. The methods were validated to be precise and accurate within the dynamic range of 5-1000 ng/mL and 0.2-50 ng/g for plasma and brain tissue samples, respectively. The lower limit of quantitation of the method was 0.2 ng/g, which was far more sensitive than all existing methods to quantify tizoxanide in biological samples. Application performed on rats exhibited that the brain-to-plasma ratio of tizoxanide ranged from 3.16 to 26.86% in 1 h after administration of 10 mg/kg nitazoxanide.


Assuntos
Encéfalo/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Tiazóis/análise , Animais , Limite de Detecção , Modelos Lineares , Masculino , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Tiazóis/química , Tiazóis/farmacocinética , Distribuição Tecidual
18.
Magn Reson Chem ; 58(1): 97-105, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31441102

RESUMO

Quantitative nuclear magnetic resonance (qNMR) is an analytical technique that offers numerous advantages in pharmaceutical applications including minimum sample preparation and rapid data collection times with no need for response factor corrections, being a powerful tool for assaying drug content in both drug discovery and early drug development. In the present work, we have applied qNMR, using both the internal standard and the electronic reference to access in vivo concentrations 2 calibration methods, to assess the purity of RI76, a novel antifungal drug candidate. NMR acquisition and processing parameters were optimized in order to obtain spectra with intense, well-resolved signals of completely relaxed nuclei. The analytical method was validated following current guidelines, demonstrating selectivity, linearity, accuracy, precision, and robustness. The calibration approaches were statistically compared, and no significant difference was observed when comparing the obtained results and their dispersion in terms of relative standard deviation. The proposed qNMR method may, therefore, be used for both qualitative and quantitative assessments of RI76 in early drug development and for characterization of this compound.


Assuntos
Antifúngicos/química , Espectroscopia de Ressonância Magnética/métodos , Tiazóis/química , Acetanilidas/química , Acetanilidas/normas , Calibragem , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Reprodutibilidade dos Testes
19.
Eur J Med Chem ; 186: 111879, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31780082

RESUMO

Adenosine acts as a powerful signaling molecule via four distinct G protein-coupled receptors, designated A1, A2A, A2B and A3 adenosine receptors (ARs). A2A and A2B ARs are Gs-coupled, while A1 and A3 ARs inhibit cAMP production via Gi proteins. Antagonists for A1 and A3 ARs may be useful for the treatment of (neuro)inflammatory diseases including acute kidney injury and kidney failure, pulmonary diseases, and Alzheimer's disease. In the present study, we optimized the versatile 2-amino-4-phenylthiazole scaffold by introducing substituents at N2 and C5 to obtain A1 and A3 AR antagonists including dual-target compounds. Selective A1 antagonists with (sub)nanomolar potency were produced, e.g. 11 and 13. These compounds showed species differences being significantly more potent at the rat as compared to the human A1 AR, and were characterized as inverse agonists. Several potent and selective A3 AR antagonists, e.g. 7, 8, 17 and 22 (Ki values of 5-9 nM at the human A3 AR) were prepared, which were much less potent at the rat orthologue. Moreover, dual A1/A3 antagonists (10, 18) were developed showing Ki values between 8 and 42 nM. Docking and molecule dynamic simulation studies using the crystal structure of the A1 AR and a homology model of the A3 AR were performed to rationalize the observed structure-activity relationships.


Assuntos
Antagonistas de Receptores Purinérgicos P1/farmacologia , Receptor A1 de Adenosina/metabolismo , Receptor A3 de Adenosina/metabolismo , Tiazóis/farmacologia , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Antagonistas de Receptores Purinérgicos P1/síntese química , Antagonistas de Receptores Purinérgicos P1/química , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/química
20.
Chem Commun (Camb) ; 56(1): 74-77, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31790117

RESUMO

We developed a new method for the de novo formation of fluorophores based on citrate (DNFC) in biological samples. Use of an amide coupling reagent and microwave irradiation greatly facilitates the fluorophore formation on peptides and proteins with N-terminal cysteine or serine. Since N-terminal cysteine and serine can form thiazolopyridone- or oxazolopyridone-based fluorophores emitting blue and green fluorescence, respectively, by the DNFC staining, each organelle, cell and tissue exhibited a characteristic fluorescence distribution. The DNFC staining is able to provide a new potential protocol for future cell imaging, histology and diagnosis.


Assuntos
Corantes Fluorescentes/metabolismo , Sondas Moleculares/metabolismo , Peptídeos/metabolismo , Proteínas/metabolismo , Animais , Linhagem Celular Tumoral , Ácido Cítrico/metabolismo , Cisteína/química , Fluorescência , Corantes Fluorescentes/química , Células HEK293 , Humanos , Camundongos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Sondas Moleculares/química , Células NIH 3T3 , Peptídeos/química , Estudo de Prova de Conceito , Proteínas/química , Piridonas/química , Piridonas/metabolismo , Serina/química , Tiazóis/química , Tiazóis/metabolismo
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