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1.
J Agric Food Chem ; 67(38): 10764-10773, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31487158

RESUMO

It has been hypothesized that the α-methylene-γ-lactone moiety of sesquiterpene lactones is a key unit for their bioactivity. As a consequence, modifications of these compounds have been focused on this fragment. In the work reported here, two sesquiterpene lactones, namely, dehydrocostuslactone and ß-cyclocostunolide, a eudesmanolide obtained by controlled cyclization of costunolide, were chosen for modification by Michael addition at C-13. On applying this reaction to both compounds, it was possible to introduce the functional groups alkoxy, amino, carbamoyl, hydroxy, and thiol to give products in good to high yields, depending on the base and solvent employed. In particular, the introduction of a thiol group at C-13 in both compounds was achieved with outstanding yields (>90%) and this is unprecedented for these sesquiterpene lactones. The bioactivities of the products were evaluated on etiolated wheat coleoptile elongation and germination of seeds of parasitic weeds, with significant activity observed on Orobanche cumana and Phelipanche ramosa. The structure-activity relationships are discussed.


Assuntos
Lactonas/química , Orobanchaceae/química , Orobanche/química , Extratos Vegetais/química , Plantas Daninhas/química , Sesquiterpenos/química , Germinação , Estrutura Molecular , Orobanchaceae/crescimento & desenvolvimento , Orobanche/crescimento & desenvolvimento , Plantas Daninhas/crescimento & desenvolvimento , Sementes/química , Sementes/crescimento & desenvolvimento , Compostos de Sulfidrila/química
2.
J Enzyme Inhib Med Chem ; 34(1): 1414-1425, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31401901

RESUMO

The emergence of drug-resistant pathogenic bacteria is occurring due to the global overuse and misuse of ß-lactam antibiotics. Infections caused by some bacteria which secrete metallo-ß-lactamases (enzymes that inactivate ß-lactam antibiotics) are increasingly prevalent and have become a major worldwide threat to human health. These bacteria are resistant to ß-lactam antibiotics and MBL-inhibitor/ß-lactam antibiotic combination therapy can be a strategy to overcome this problem. So far, no clinically available inhibitors of metallo-ß-lactamases (MBLs) have been reported. In this study, L-benzyl tyrosine thiol carboxylic acid analogues (2a-2k) were synthesized after the study of computational simulation by adding of methyl, chloro, bromo and nitro groups to the benzyl ring for investigation of SAR analysis. Although the synthesized molecules 2a-k shows the potent inhibitory effects against metallo-ß-lactamase (IMP-1) with the range of Kic values of 1.04-4.77 µM, they are not as potent as the candidate inhibitor.


Assuntos
Ácidos Carboxílicos/síntese química , Ácidos Carboxílicos/farmacologia , Compostos de Sulfidrila/química , Tirosina/química , Inibidores de beta-Lactamases/síntese química , Inibidores de beta-Lactamases/farmacologia , beta-Lactamases/efeitos dos fármacos , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Ácidos Carboxílicos/química , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Espectroscopia de Prótons por Ressonância Magnética , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/enzimologia , Serratia marcescens/efeitos dos fármacos , Serratia marcescens/enzimologia , Relação Estrutura-Atividade , Inibidores de beta-Lactamases/química
3.
Chem Biol Interact ; 311: 108787, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31400341

RESUMO

Antipsychotic drugs interfere with the antioxidant defense system provoking complex and often toxicological effects. Here we examined differences in plasma albumin reduced free thiol (SH) group content and its reactivity as a consequence of clozapine (CLZ) and ziprasidone (ZIP) binding. Chronic administration of CLZ reduced, whereas treatment with ZIP increased albumin-SH content in rats. Regardless of the ratio of stearic acid (SA) bound to protein, in vitro binding of ZIP to human serum albumin (HSA) increased both the SH group level and reactivity. In contrast, the effect of CLZ on HSA-SH reactivity was dependent on HSA to SA molar ratio. CLZ binding was accompanied by an increase in HSA-SH reactivity in samples with normal, but a reduction of its reactivity level with higher SA/HSA ratio, compared to drug-free samples. We demonstrate by steady-state fluorescence quenching studies that an increase in SA binding to HSA is associated with a significant reduction of binding constant for both antipsychotics. In addition, this is the first report of quantitative characterization of ZIP binding to HSA. Our findings suggest that albumin-SH content and reactivity is modulated by ZIP towards an increased antioxidant defense capacity in circulation, as opposed to CLZ, which can contribute to the safer, more effective treatment of schizophrenia.


Assuntos
Clozapina/química , Ácidos Graxos/química , Piperazinas/química , Albumina Sérica/química , Compostos de Sulfidrila/química , Tiazóis/química , Animais , Clozapina/metabolismo , Ácidos Graxos/metabolismo , Humanos , Masculino , Piperazinas/metabolismo , Ligação Proteica , Ratos , Ratos Wistar , Albumina Sérica/metabolismo , Espectrometria de Fluorescência , Espectrofotometria , Compostos de Sulfidrila/análise , Compostos de Sulfidrila/metabolismo , Tiazóis/metabolismo
4.
Chem Commun (Camb) ; 55(65): 9697-9700, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31347623

RESUMO

An ultra-high sensitivity sensor with the function of chiral signal amplification has been proposed for the enantiomer discrimination of various amino acid enantiomers based on charge transfer (CT)-induced SERS spectroscopy. The introduced TiO2 in this sensor improves the CT behavior and discrimination efficiency distinctly and enantiomeric discrimination is realized even at low concentration.


Assuntos
Compostos de Anilina/química , Nanopartículas Metálicas/química , Compostos de Sulfidrila/química , Triptofano/análise , beta-Ciclodextrinas/química , Ligações de Hidrogênio , Fenilalanina/análise , Fenilalanina/química , Prata/química , Análise Espectral Raman/métodos , Estereoisomerismo , Titânio/química , Triptofano/química , Tirosina/análise , Tirosina/química
5.
Nature ; 571(7766): 546-549, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31292542

RESUMO

Amide bond formation is one of the most important reactions in both chemistry and biology1-4, but there is currently no chemical method of achieving α-peptide ligation in water that tolerates all of the 20 proteinogenic amino acids at the peptide ligation site. The universal genetic code establishes that the biological role of peptides predates life's last universal common ancestor and that peptides played an essential part in the origins of life5-9. The essential role of sulfur in the citric acid cycle, non-ribosomal peptide synthesis and polyketide biosynthesis point towards thioester-dependent peptide ligations preceding RNA-dependent protein synthesis during the evolution of life5,9-13. However, a robust mechanism for aminoacyl thioester formation has not been demonstrated13. Here we report a chemoselective, high-yielding α-aminonitrile ligation that exploits only prebiotically plausible molecules-hydrogen sulfide, thioacetate12,14 and ferricyanide12,14-17 or cyanoacetylene8,14-to yield α-peptides in water. The ligation is extremely selective for α-aminonitrile coupling and tolerates all of the 20 proteinogenic amino acid residues. Two essential features enable peptide ligation in water: the reactivity and pKaH of α-aminonitriles makes them compatible with ligation at neutral pH and N-acylation stabilizes the peptide product and activates the peptide precursor to (biomimetic) N-to-C peptide ligation. Our model unites prebiotic aminonitrile synthesis and biological α-peptides, suggesting that short N-acyl peptide nitriles were plausible substrates during early evolution.


Assuntos
Evolução Química , Nitrilos/química , Nitrilos/síntese química , Origem da Vida , Peptídeos/química , Peptídeos/síntese química , Água/química , Acetileno/análogos & derivados , Acetileno/química , Dipeptídeos/síntese química , Dipeptídeos/química , Ferricianetos/química , Sulfeto de Hidrogênio/química , Concentração de Íons de Hidrogênio , Oxirredução , Compostos de Sulfidrila/química , Sulfetos/química
6.
Food Chem ; 298: 124868, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260976

RESUMO

This work aimed to evaluate the efficacy of protein hydrolysates from bighead carp gill in inhibiting protein oxidation and quality loss in surimi. Firstly, antioxidant activity of hydrolysates in vitro was assessed, then 1%, 2% hydrolysates with better antioxidant activity and 4% sucrose were added to surimi respectively and stored at -18 °C for 4 months. Peptide sequences of above hydrolysates were also identified. The results suggested that hydrolysates of neutral protease had excellent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability (42.93%) and Fe2+-chelating activity (73.27%). Compared with surimi without treatments, surimi with hydrolysates had higher sulfhydryl and salt-soluble protein concentrations, greater Ca2+-ATPase activity, lower disulfide bonds, carbonyls and hydrophobicity, as well as better gel strength and texture (p < 0.05). This study demonstrated that gill hydrolysate had antioxidant and dose-dependent cryoprotective effects on surimi that were comparable to the effects of sucrose, representing it as an alternative to sugar cryoprotectants in surimi industry.


Assuntos
Antioxidantes/farmacologia , Cyprinidae , Produtos Pesqueiros , Proteínas de Peixes/farmacologia , Hidrolisados de Proteína/farmacologia , Animais , Antioxidantes/química , Crioprotetores/química , Crioprotetores/farmacologia , Proteínas de Peixes/química , Congelamento , Brânquias/química , Interações Hidrofóbicas e Hidrofílicas , Oxirredução , Peptídeos/análise , Hidrolisados de Proteína/química , Compostos de Sulfidrila/química
7.
Food Chem ; 298: 124952, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260994

RESUMO

The riboflavin-mediated photo-degradation of methionine in white wine has been related to onset of undesired light-struck taste. This research investigated the effects of different concentrations of riboflavin and methionine, hydrolysable tannins from various sources (nut galls, chestnut and oak woods) and sulfur dioxide on methionine degradation in a model wine exposed to light. Increased methionine concentration resulted in its increased degradation with the consequent formation of volatile sulfur compounds, namely methanethiol, dimethyl disulphide and dimethyl trisulphide. Tannins, especially nut gall tannin, were effective in limiting both methionine degradation and the production of volatile sulfur compounds. Sulfur dioxide enhanced the methionine degradation although the light-struck taste was not perceived when sulfur dioxide concentration was higher than 50 mg/L. In conclusion, the use of hydrolysable tannins can represent a promising tool for protecting white wine against the light-struck taste also limiting the use of sulfur dioxide.


Assuntos
Taninos Hidrolisáveis/química , Metionina/química , Riboflavina/química , Dióxido de Enxofre/química , Vinho , Dissulfetos/química , Luz , Metionina/metabolismo , Processos Fotoquímicos , Compostos de Sulfidrila/química , Paladar/efeitos dos fármacos , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo , Vinho/análise
8.
Nature ; 571(7765): 419-423, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31292545

RESUMO

Single-cell RNA sequencing (scRNA-seq) has highlighted the important role of intercellular heterogeneity in phenotype variability in both health and disease1. However, current scRNA-seq approaches provide only a snapshot of gene expression and convey little information on the true temporal dynamics and stochastic nature of transcription. A further key limitation of scRNA-seq analysis is that the RNA profile of each individual cell can be analysed only once. Here we introduce single-cell, thiol-(SH)-linked alkylation of RNA for metabolic labelling sequencing (scSLAM-seq), which integrates metabolic RNA labelling2, biochemical nucleoside conversion3 and scRNA-seq to record transcriptional activity directly by differentiating between new and old RNA for thousands of genes per single cell. We use scSLAM-seq to study the onset of infection with lytic cytomegalovirus in single mouse fibroblasts. The cell-cycle state and dose of infection deduced from old RNA enable dose-response analysis based on new RNA. scSLAM-seq thereby both visualizes and explains differences in transcriptional activity at the single-cell level. Furthermore, it depicts 'on-off' switches and transcriptional burst kinetics in host gene expression with extensive gene-specific differences that correlate with promoter-intrinsic features (TBP-TATA-box interactions and DNA methylation). Thus, gene-specific, and not cell-specific, features explain the heterogeneity in transcriptomes between individual cells and the transcriptional response to perturbations.


Assuntos
Regulação da Expressão Gênica/genética , Análise de Sequência de RNA/métodos , Análise de Célula Única , Transcrição Genética/genética , Alquilação , Animais , Ciclo Celular , Citomegalovirus/fisiologia , Metilação de DNA , Fibroblastos/metabolismo , Fibroblastos/virologia , Cinética , Camundongos , Regiões Promotoras Genéticas/genética , RNA/análise , RNA/química , Compostos de Sulfidrila/química
9.
Food Chem ; 298: 125087, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31272052

RESUMO

In this study, comprehensive analysis was performed to evaluate the impact of high hydrostatic pressure (HHP) and traditional thermal processing methods (baking and steaming) on cod proteins. Results showed that HHP, but not baking or steaming, was able to increase the content of soluble protein nitrogen (1.42-fold), compared with control. Total peptide contents of HHP-treated samples were also significantly higher than baked and steamed ones. In addition, protein oxidation was greatly increased after baking (1.56-fold) and steaming (1.97-fold), whereas HHP did not exhibit any appreciable effect. Furthermore, the allergenicity of cod was significantly reduced after HHP as reflected by the attenuated IgE and IgG-binding capacities (67-84% relative to control), while baking and steaming resulted in higher allergenicity. This study strongly supports the potential of HHP for reducing allergenicity, avoiding protein oxidation, and improving digestibility of cod and other protein-rich foods susceptible to quality deterioration during thermal processing.


Assuntos
Proteínas de Peixes da Dieta/química , Hipersensibilidade Alimentar/prevenção & controle , Indústria de Processamento de Alimentos/métodos , Gadus morhua , Animais , Culinária , Digestão , Produtos Pesqueiros/análise , Proteínas de Peixes da Dieta/farmacocinética , Hipersensibilidade Alimentar/imunologia , Humanos , Interações Hidrofóbicas e Hidrofílicas , Pressão Hidrostática , Imunoglobulina G/metabolismo , Nitrogênio/análise , Oxirredução , Carbonilação Proteica , Vapor , Compostos de Sulfidrila/análise , Compostos de Sulfidrila/química
10.
Food Chem ; 293: 529-536, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151644

RESUMO

The effect of glucose oxidase (GOx) catalytic oxidation on the efficacy of gallic acid (GA) to modify the chemical structure and gelling behavior of myofibrillar protein (MP) was investigated. In contrast to non-oxidized MP samples where GA induced very little changes, GA (0, 6, 30, and 60 µmol/g MP) under GOx treatment promoted sulfhydryl and amine loss (up to 58% and 49%, respectively). The attenuation of intrinsic tryptophan fluorescence in the GA/GOx-treated MP corroborated the finding. The gelling capacity of MP, corresponding to disulfide and non-disulfide bond formation in protein aggregates, was markedly enhanced by 60 µmol GA under GOx, up to 86% in gel storage modulus G' and 53% in gel strength. The GOx-aided GA modification of MP could be a potential ingredient strategy in meat processing to promote textural attributes of cooked products.


Assuntos
Ácido Gálico/química , Géis/química , Glucose Oxidase/metabolismo , Proteínas Musculares/química , Aminas/química , Aminas/metabolismo , Animais , Ácido Gálico/metabolismo , Carne/análise , Microscopia Eletrônica de Varredura , Proteínas Musculares/metabolismo , Oxirredução , Reologia , Compostos de Sulfidrila/química , Compostos de Sulfidrila/metabolismo
11.
Talanta ; 202: 486-493, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31171211

RESUMO

A completely new voltammetric method has been developed for quantitative determination of food additive Taurine (Tau) in energy drinks. This electroanalytical method is based on voltammetric oxidation of o-phthalaldehyde-ethanthiol derivative of Tau at glassy carbon electrode in 95% methanol containing 0.1 mol L-1 lithium perchlorate. Working conditions necessary for quantitative Tau derivatization reaction and electrochemical detection using square wave voltammetry were optimized. Linear range from 1.0 × 10-5 to 1.0 × 10-4 mol L-1 characterized by coefficient of determination 0.9998, limits of quantification 6.8 × 10-6 mol L-1 and detection 2.1 × 10-6 mol L-1 were obtained at pulse amplitude 50 mV and frequency 80 Hz. Analytical method of calibration curve was used for evaluation of Tau content in several commercially available energy drinks. The procedure was validated using standard reference high performance liquid chromatography (HPLC) method. Both methods showed nearly identical Tau content, around 0.35% (w/w). Besides its reliability to the Tau determination, that is totally comparable to reference method used, present voltammetric approach is more advantageous on the economic and simplicity basis. Finally, developed voltammetric method could find employment in food quality control.


Assuntos
Técnicas Eletroquímicas , Bebidas Energéticas/análise , Compostos de Sulfidrila/química , Taurina/análise , o-Ftalaldeído/química , Calibragem , Cromatografia Líquida de Alta Pressão , Qualidade dos Alimentos
12.
Food Chem ; 295: 449-455, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174781

RESUMO

The aroma stability of fresh coffee brew was investigated during storage over 60 min, there was a substantial reduction in available 2-furfurylthiol (2-FFT) (84%), methanethiol (72%), 3-methyl-1H-pyrole (68%) and an increase of 2-pentylfuran (65%). It is proposed that 2-FFT was reduced through reversible chemical binding and irreversible losses. Bound 2-FFT was released after cysteine addition, thereby demonstrating that a reversible binding reaction was the dominant mechanism of 2-FFT loss in natural coffee brew. The reduction in available 2-FFT was investigated at different pH and temperatures. At high pH, the reversible binding of 2-FFT was shown to protect 2-FFT from irreversible losses, while irreversible losses led to the reduction of total 2-FFT at low pH. A model reaction system was developed and a potential conjugate, hydroxyhydroquinone, was reacted with 2-FFT. Hydroxyhydroquinone also showed 2-FFT was released after cysteine addition at high pH.


Assuntos
Café/química , Armazenamento de Alimentos/métodos , Furanos/química , Odorantes/análise , Compostos de Sulfidrila/química , Furanos/análise , Concentração de Íons de Hidrogênio , Compostos de Sulfidrila/análise , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química
13.
Chem Commun (Camb) ; 55(56): 8130-8133, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31237579

RESUMO

A robust fluorescent probe, MCP1, was developed for triple-detection of H2S, H2Sn and biothiols for the first time. Introduction of H2S, H2Sn and biothiols to MCP1 lead to distinct emission peaks at 508, 576 and 469 nm, respectively, enabling simultaneous detection of H2S, H2Sn and biothiols from distinct emission channels.


Assuntos
Corantes Fluorescentes/química , Sulfeto de Hidrogênio/química , Compostos de Sulfidrila/química , Animais , Espectrometria de Massas/métodos , Camundongos , Células RAW 264.7 , Espectrometria de Fluorescência/métodos , Espectrofotometria Ultravioleta/métodos
14.
Inorg Chem ; 58(16): 10501-10507, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31247870

RESUMO

Zinc thiolate bonds are intriguing targets of study because of their redox noninnocence and prevalence in bioinorganic sites. A five-coordinate zinc dithiolate complex [Et4N]2[LZn] (H4L = N,N'-di(2-sulfhydrylphenyl)-pyridine-2,6-dicarboxamide) was synthesized to study the oxidative reactivity of zinc thiolate bonds. Multiple chemically reversible reactions of the zinc thiolate bonds were identified. Oxidation of [Et4N]2[LZn] with iodine resulted in structural rearrangement to a bimetallic disulfide-bridged complex. In contrast, the addition of elemental sulfur to [Et4N]2[LZn] resulted in the insertion of a neutral S3 fragment into the Zn-thiolate bond to selectively form an unusual monometallic tetrasulfanido complex. When oxidized, this tetrasulfanido compound rearranged to form a bimetallic trisulfide-bridged complex. The observed diversity of zinc thiolate reactivity, particularly with sulfur, is likely important in biological contexts.


Assuntos
Complexos de Coordenação/química , Compostos de Sulfidrila/química , Sulfetos/química , Enxofre/química , Zinco/química , Modelos Moleculares , Estrutura Molecular , Oxirredução
15.
Talanta ; 201: 119-125, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31122401

RESUMO

Glycated hemoglobin (HbA1c) represents the average glucose level over the past three months and has been considered as the most important biomarker for the diagnosis of Type Ⅱ diabetes (T2D). Herein, a label-free and quantitative electrochemical biosensor based on 4-mercaptophenylboronic acid (4-MPBA) modified gold nano-flowers (Au NFs) substrate was developed for the determination of HbA1c. Under optimal conditions, the linear dynamic ranges of HbA1c (5 µg/mL - 1000 µg/mL) and HbA1c% (2%-20%) by cyclic voltammetry were achieved. The electrochemical biosensor showed great detection specificity towards HbA1c and relatively stability after storage at 4 °C. This method could also be applied in human serum system which holds great potential to be applied to monitor real blood samples of diabetes patients. In human serum system, the recovery rate could reach 103.8% and 99.0%. It could achieve fast detection, the total analysis time was less than 65 min, and the detection time was less than 10 s. Moreover, in terms of fabrication process, operation procedure, detection time and cost, this technique was superior to the current HbA1c detection methods suggesting great promise for the practical clinical use in the future.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Hemoglobina A Glicada/análise , Ouro/química , Nanopartículas Metálicas/química , Técnicas Biossensoriais/instrumentação , Ácidos Borônicos/química , Carbono/química , Técnicas Eletroquímicas/instrumentação , Eletrodos , Hemoglobina A Glicada/química , Humanos , Peróxido de Hidrogênio/química , Limite de Detecção , Oxirredução , Compostos de Sulfidrila/química
16.
Talanta ; 201: 465-473, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31122452

RESUMO

We report results of the studies relating to the fabrication of a surface plasmon resonance (SPR) based label-free immunosensor for real-time monitoring of endothelin-1 (ET-1), a colon cancer biomarker. A gold disk modified with a self-assembled monolayer (SAM) of 11-mercaptoundecanoic acid (11-MUA) was functionalised via covalent immobilization of monoclonal anti-ET-1 antibodies using EDC-NHS (1-(3-(dimethylamine)-propyl)-3-ethylcarbodiimide hydrochloride, N-hydroxy succinimide) chemistry. This immunosensing platform (ethanolamine/anti-ET-1/11-MUA/Au) was characterized via atomic force microscopy (AFM), contact angle (CA) and Fourier transform infrared (FT-IR) spectroscopic techniques. The fabricated SPR electrode was further used to detect ET-1 in the broad concentration range 2-100 pg mL-1, with a detection limit of 0.30 pg mL-1 and remarkable sensitivity of 2.18 mo pg-1mL. The adsorption mechanism was studied using monophasic model and the values of association (ka) and dissociation (kd) constants for anti-ET-1 and ET-1 binding were calculated to be 4.4 ±â€¯0.4 × 105 M-1 s-1 and 2.04 ±â€¯0.0003 × 10-3 s-1, respectively. The results obtained via analysis of serum samples of colorectal cancer patients were found to be in good agreement with those obtained from enzyme-linked immunosorbent assay (ELISA) technique. Further, electrochemical studies were performed to prove the efficacy of the fabricated platform as a point of care device for the detection of ET-1.


Assuntos
Técnicas Biossensoriais/métodos , Neoplasias do Colo/diagnóstico , Técnicas Eletroquímicas/métodos , Endotelina-1/sangue , Ressonância de Plasmônio de Superfície/métodos , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/imunologia , Neoplasias do Colo/sangue , Técnicas Eletroquímicas/instrumentação , Eletrodos , Endotelina-1/imunologia , Ácidos Graxos/química , Ouro/química , Humanos , Cinética , Limite de Detecção , Compostos de Sulfidrila/química
17.
Analyst ; 144(11): 3552-3555, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31049496

RESUMO

Here we demonstrate light mediated heating of nanoparticles confined deep inside mammalian tissue, whilst directly monitoring their temperature non-invasively using a form of deep Raman spectroscopy, T-SESORS. One of the main barriers to the introduction of photo-thermal therapies (PTT) has been recognised as the inability to directly monitor the local temperature deep within the tissue at the point of therapy. Here Au nanoparticles with a Raman reporter molecule (temperature reporters) are used in combination with Au nanoshells (heat mediators) to provide simultaneously heating under NIR illumination and direct spectroscopic monitoring of local temperature deep within mammalian tissues. The surface enhanced Raman signal was read out at the tissue surface using a transmission geometry in this example and the temperature of the tissue was ascertained from the anti-Stokes to Stokes Raman reporter. This approach opens the prospect of non-invasive hyperthermia treatments with direct temperature feedback from deep inside within tissue, where nanoparticles can be used to both provide localised heating and accurately monitor the local temperature.


Assuntos
Febre/metabolismo , Análise Espectral Raman/métodos , Temperatura Ambiente , Termometria/métodos , Animais , Benzoatos/química , Benzoatos/efeitos da radiação , Ouro/química , Raios Infravermelhos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/efeitos da radiação , Estudo de Prova de Conceito , Compostos de Sulfidrila/química , Compostos de Sulfidrila/efeitos da radiação , Suínos
18.
Chem Commun (Camb) ; 55(47): 6629-6671, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31119257

RESUMO

In the past few years, the preparation of novel small-molecule fluorescent probes for specific detection and imaging of chemical species inside lysosomes has attracted considerable attention because of their wide applications in chemistry, biology, and medical science. This feature article summarizes the recent advances in the design and preparation of small-molecule fluorescent probes for specific detection of chemical species inside lysosomes. In addition, their properties and applications for the detection and imaging of pH, H2O2, HOCl, O2˙-, lipid peroxidation, H2S, HSO3-, thiols, NO, ONOO-, HNO, Zn2+, Cu2+, enzymes, etc. in lysosomes are discussed as well.


Assuntos
Corantes Fluorescentes/química , Lisossomos/química , Animais , Infecções Bacterianas/patologia , Infecções Bacterianas/veterinária , Linhagem Celular , Humanos , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Peroxidação de Lipídeos , Lisossomos/metabolismo , Camundongos , Microscopia Confocal , Ratos , Compostos de Sulfidrila/química
19.
Chem Commun (Camb) ; 55(44): 6193-6196, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31070620

RESUMO

Hydrogen sulfide (H2S) is an important signaling molecule with promising protective effects in many physiological and pathological processes. However, the study of H2S has been impeded by the lack of appropriate H2S donors that could mimic its slow-releasing process in vivo. Herein, we report the rational design, synthesis, and biological evaluation of a series of thioester-based H2S donors. These cysteine-activated H2S donors release H2S in a slow and controllable manner. Most of the donors comprising an allyl moiety showed significant cytoprotective effects in H9c2 cellular models of oxidative damage. The most potent donor 5e decreased the mitochondrial membrane potential (MMP) loss and lactate dehydrogenase (LDH) release in H2O2-stimulated H9c2 cells. More importantly, donor 5e exhibited a potent cardioprotective effect in an in vivo myocardial infarction (MI) mouse model by reducing myocardial infarct size and cardiomyocyte apoptosis. Taken together, our studies demonstrated that these new allyl thioesters are potential cardioprotective agents by releasing H2S.


Assuntos
Cardiotônicos/farmacologia , Cardiotônicos/uso terapêutico , Ésteres/química , Sulfeto de Hidrogênio/química , Compostos de Sulfidrila/química , Animais , Linhagem Celular , Modelos Animais de Doenças , Peróxido de Hidrogênio/farmacologia , L-Lactato Desidrogenase/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/enzimologia , Infarto do Miocárdio/metabolismo , Estresse Oxidativo
20.
Org Lett ; 21(10): 3828-3833, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-31058515

RESUMO

A chemoselective primary amine modification strategy that enables the three-component, one-pot bioconjugation is described. The specifically designed, mercaptobenzaldehyde-based bifunctional linker achieves highly selective and robust amine labeling under biocompatible conditions. This linker demonstrates wide functional group tolerance and is simple to prepare, which allowed facile payload incorporation. Finally, our studies have shown that the introduction of linker does not impair the function of modified protein such as insulin.


Assuntos
Aminas/química , Benzaldeídos/química , Processamento de Proteína Pós-Traducional/genética , Compostos de Sulfidrila/química , Estrutura Molecular
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