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1.
Nat Commun ; 11(1): 4857, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978402

RESUMO

Characterization of the dynamic conformational changes in membrane protein signaling complexes by nuclear magnetic resonance (NMR) spectroscopy remains challenging. Here we report the site-specific incorporation of 4-trimethylsilyl phenylalanine (TMSiPhe) into proteins, through genetic code expansion. Crystallographic analysis revealed structural changes that reshaped the TMSiPhe-specific amino-acyl tRNA synthetase active site to selectively accommodate the trimethylsilyl (TMSi) group. The unique up-field 1H-NMR chemical shift and the highly efficient incorporation of TMSiPhe enabled the characterization of multiple conformational states of a phospho-ß2 adrenergic receptor/ß-arrestin-1(ß-arr1) membrane protein signaling complex, using only 5 µM protein and 20 min of spectrum accumulation time. We further showed that extracellular ligands induced conformational changes located in the polar core or ERK interaction site of ß-arr1 via direct receptor transmembrane core interactions. These observations provided direct delineation and key mechanism insights that multiple receptor ligands were able to induce distinct functionally relevant conformational changes of arrestin.


Assuntos
Arrestina/química , Arrestina/genética , Arrestina/metabolismo , Ligantes , Espectroscopia de Prótons por Ressonância Magnética/métodos , Sítios de Ligação , Cristalografia por Raios X , Humanos , Modelos Moleculares , Fenilalanina , Ligação Proteica , Conformação Proteica , Receptores Adrenérgicos beta 2/metabolismo , Transdução de Sinais , beta-Arrestina 1/química , beta-Arrestina 1/genética , beta-Arrestina 1/metabolismo
2.
Nat Commun ; 11(1): 4372, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873801

RESUMO

3D molecular structure determination is a challenge for organic compounds or natural products available in minute amounts. Proton/proton and proton/carbon correlations yield the constitution. J couplings and NOEs oftentimes supported by one-bond 1H,13C residual dipolar couplings (RDCs) or by 13C residual chemical shift anisotropies (RCSAs) provide the relative configuration. However, these RDCs or carbon RCSAs rely on 1% natural abundance of 13C preventing their use for compounds available only in quantities of a few 10's of µgs. By contrast, 1H RCSAs provide similar information on spatial orientation of structural moieties within a molecule, while using the abundant 1H spin. Herein, 1H RCSAs are accurately measured using constrained aligning gels or liquid crystals and applied to the 3D structural determination of molecules with varying complexities. Even more, deuterated alignment media allow the elucidation of the relative configuration of around 35 µg of a briarane compound isolated from Briareum asbestinum.


Assuntos
Antozoários/química , Produtos Biológicos/química , Diterpenos/química , Conformação Molecular , Prótons , Animais , Anisotropia , Espectroscopia de Prótons por Ressonância Magnética
3.
J Chromatogr A ; 1626: 461351, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797831

RESUMO

Traditional polymer-separation methods, such as size-exclusion chromatography and (gradient) liquid adsorption chromatography, cannot provide separations exclusively based on the number of deprotonated carboxylic-acid groups along the backbone chain of polymers. A novel separation method, based on non-aqueous ion-exchange chromatography (NAIEX), was developed, which allows such a separation of acid-functional polymers that are soluble in organic solvents. The polar, aprotic N-methyl-2-pyrrolidone was found to be a suitable solvent. It features a high relative permittivity (favouring dissociation of ion pairs into free ions) and it is a good solvent for polymers and organic salts, such as triethyl-ammonium formate. A negative charge is established on these polymers by deprotonation of the carboxylic-acid groups in the presence of an organic superbase (tetramethyl guanidine). Traditional potent organic bases, such as triethylamine, do not possess the base strength to compensate for the increase in pKa of polymeric carboxylic acid groups in non-aqueous conditions. Triethyl-ammonium formate is proposed as an alternative to traditional salts used for elution in aqueous ion-exchange chromatography. Separation was performed on an industry-standard strong-anion-exchange column and (near-)universal detection of the polymers was performed by high-temperature evaporative-light-scattering detection. The NAIEX method yielded a separation based on the acid-functionality distribution of the polymer. NAIEX was compared with traditional normal- and reversed-phase liquid-chromatography approaches for the separation of acid-functional copolymers.


Assuntos
Cromatografia por Troca Iônica/métodos , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Polímeros/química , Espectroscopia de Prótons por Ressonância Magnética , Sais/química , Solventes/química
4.
Int J Nanomedicine ; 15: 4779-4791, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32753866

RESUMO

Background: Considering the timeline required for the development of novel antimicrobial drugs, increased attention should be given to repurposing old drugs and improving antimicrobial efficacy, particularly for chronic infections associated with biofilms. Methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) are common causes of biofilm-associated infections but produce different biofilm matrices. MSSA biofilm cells are typically embedded in an extracellular polysaccharide matrix, whereas MRSA biofilms comprise predominantly of surface proteins and extracellular DNA (eDNA). Nanoparticles (NPs) have the potential to enhance the delivery of antimicrobial agents into biofilms. However, the mechanisms which influence the interactions between NPs and the biofilm matrix are not yet fully understood. Methods: To investigate the influence of NPs surface chemistry on vancomycin (VAN) encapsulation and NP entrapment in MRSA and MSSA biofilms, mesoporous silica nanoparticles (MSNs) with different surface functionalization (bare-B, amine-D, carboxyl-C, aromatic-A) were synthesised using an adapted Stöber method. The antibacterial efficacy of VAN-loaded MSNs was assessed against MRSA and MSSA biofilms. Results: The two negatively charged MSNs (MSN-B and MSN-C) showed a higher VAN loading in comparison to the positively charged MSNs (MSN-D and MSN-A). Cellular binding with MSN suspensions (0.25 mg mL-1) correlated with the reduced viability of both MSSA and MRSA biofilm cells. This allowed the administration of low MSNs concentrations while maintaining a high local concentration of the antibiotic surrounding the bacterial cells. Conclusion: Our data suggest that by tailoring the surface functionalization of MSNs, enhanced bacterial cell targeting can be achieved, leading to a novel treatment strategy for biofilm infections.


Assuntos
Anti-Infecciosos/farmacologia , Biofilmes , Staphylococcus aureus Resistente à Meticilina/fisiologia , Nanopartículas/química , Biofilmes/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/ultraestrutura , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Espectroscopia de Prótons por Ressonância Magnética , Dióxido de Silício/química , Vancomicina/farmacologia
5.
Biomol NMR Assign ; 14(2): 329-333, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32770392

RESUMO

The ongoing pandemic caused by the Betacoronavirus SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) demonstrates the urgent need of coordinated and rapid research towards inhibitors of the COVID-19 lung disease. The covid19-nmr consortium seeks to support drug development by providing publicly accessible NMR data on the viral RNA elements and proteins. The SARS-CoV-2 genome encodes for approximately 30 proteins, among them are the 16 so-called non-structural proteins (Nsps) of the replication/transcription complex. The 217-kDa large Nsp3 spans one polypeptide chain, but comprises multiple independent, yet functionally related domains including the viral papain-like protease. The Nsp3e sub-moiety contains a putative nucleic acid-binding domain (NAB) with so far unknown function and consensus target sequences, which are conceived to be both viral and host RNAs and DNAs, as well as protein-protein interactions. Its NMR-suitable size renders it an attractive object to study, both for understanding the SARS-CoV-2 architecture and drugability besides the classical virus' proteases. We here report the near-complete NMR backbone chemical shifts of the putative Nsp3e NAB that reveal the secondary structure and compactness of the domain, and provide a basis for NMR-based investigations towards understanding and interfering with RNA- and small-molecule-binding by Nsp3e.


Assuntos
Betacoronavirus/metabolismo , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Isótopos de Nitrogênio/química , Ácidos Nucleicos/metabolismo , Espectroscopia de Prótons por Ressonância Magnética , Proteínas não Estruturais Virais/química , Ligação Proteica , Domínios Proteicos
6.
Biomol NMR Assign ; 14(2): 339-346, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32803496

RESUMO

The SARS-CoV-2 genome encodes for approximately 30 proteins. Within the international project COVID19-NMR, we distribute the spectroscopic analysis of the viral proteins and RNA. Here, we report NMR chemical shift assignments for the protein Nsp3b, a domain of Nsp3. The 217-kDa large Nsp3 protein contains multiple structurally independent, yet functionally related domains including the viral papain-like protease and Nsp3b, a macrodomain (MD). In general, the MDs of SARS-CoV and MERS-CoV were suggested to play a key role in viral replication by modulating the immune response of the host. The MDs are structurally conserved. They most likely remove ADP-ribose, a common posttranslational modification, from protein side chains. This de-ADP ribosylating function has potentially evolved to protect the virus from the anti-viral ADP-ribosylation catalyzed by poly-ADP-ribose polymerases (PARPs), which in turn are triggered by pathogen-associated sensing of the host immune system. This renders the SARS-CoV-2 Nsp3b a highly relevant drug target in the viral replication process. We here report the near-complete NMR backbone resonance assignment (1H, 13C, 15N) of the putative Nsp3b MD in its apo form and in complex with ADP-ribose. Furthermore, we derive the secondary structure of Nsp3b in solution. In addition, 15N-relaxation data suggest an ordered, rigid core of the MD structure. These data will provide a basis for NMR investigations targeted at obtaining small-molecule inhibitors interfering with the catalytic activity of Nsp3b.


Assuntos
Adenosina Difosfato Ribose/metabolismo , Apoproteínas/química , Betacoronavirus/metabolismo , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Isótopos de Nitrogênio/química , Espectroscopia de Prótons por Ressonância Magnética , Proteínas não Estruturais Virais/química , Sequência de Aminoácidos , Apoproteínas/metabolismo , Domínios Proteicos , Estrutura Secundária de Proteína , Proteínas não Estruturais Virais/metabolismo
7.
Food Chem ; 332: 127424, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32619947

RESUMO

Celery (Apium graveolens L. var dulce) is a widely cultivated vegetable which is popularly consumed due to its nutrient content and contains bioactive metabolites with positive effects on human physiology. In this study, 1H NMR spectroscopy coupled with multivariate statistical analyses was used to distinguish celery stem and leaf samples from different geographical origins. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were employed to investigate the differences between celery extracts from three geographical origins: Australia, Taiwan and China. Sugars, amino acids and organic acids were found to contribute significantly to the differentiation between origins, with mannitol identified as an important discriminating metabolite. It was demonstrated that NMR-based metabolomics is an effective approach for establishing reliable metabolomic fingerprints and profiles, enabling the identification of metabolite biomarkers for the possible discrimination of geographical origin.


Assuntos
Apium/química , Metabolômica/métodos , Espectroscopia de Prótons por Ressonância Magnética/métodos , Aminoácidos/análise , Apium/metabolismo , Austrália , China , Análise Discriminante , Humanos , Análise dos Mínimos Quadrados , Manitol/análise , Manitol/metabolismo , Análise Multivariada , Folhas de Planta/química , Análise de Componente Principal , Verduras/química , Verduras/metabolismo
8.
Nat Commun ; 11(1): 3541, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32669562

RESUMO

Dynamic spatiotemporal patterns that arise from out-of-equilibrium biochemical reactions generate forces in living cells. Despite considerable recent efforts, rational design of spatiotemporal patterns in artificial molecular systems remains at an early stage of development. Here, we describe force generation by a propagating wave of supramolecular nanofibers. Inspired by actin dynamics, a reaction network is designed to control the formation and degradation of nanofibers by two chemically orthogonal stimuli. Real-time fluorescent imaging successfully visualizes the propagating wave based on spatiotemporally coupled generation and collapse of nanofibers. Numerical simulation indicates that the concentration gradient of degradation stimulus and the smaller diffusion coefficient of the nanofiber are critical for wave emergence. Moreover, the force (0.005 pN) generated by chemophoresis and/or depletion force of this propagating wave can move nanobeads along the wave direction.


Assuntos
Modelos Químicos , Nanofibras/química , Hidrogéis/química , Cinética , Fenômenos Mecânicos , Estrutura Molecular , Nanofibras/ultraestrutura , Espectroscopia de Prótons por Ressonância Magnética
9.
Nat Commun ; 11(1): 2820, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32499486

RESUMO

As an intrinsically disordered protein, monomeric alpha-synuclein (aSyn) occupies a large conformational space. Certain conformations lead to aggregation prone and non-aggregation prone intermediates, but identifying these within the dynamic ensemble of monomeric conformations is difficult. Herein, we used the biologically relevant calcium ion to investigate the conformation of monomeric aSyn in relation to its aggregation propensity. We observe that the more exposed the N-terminus and the beginning of the NAC region of aSyn are, the more aggregation prone monomeric aSyn conformations become. Solvent exposure of the N-terminus of aSyn occurs upon release of C-terminus interactions when calcium binds, but the level of exposure and aSyn's aggregation propensity is sequence and post translational modification dependent. Identifying aggregation prone conformations of monomeric aSyn and the environmental conditions they form under will allow us to design new therapeutics targeted to the monomeric protein.


Assuntos
Agregados Proteicos , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo , Benzotiazóis/metabolismo , Cálcio/metabolismo , Humanos , Cinética , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Mutação/genética , Fosforilação , Conformação Proteica , Espectroscopia de Prótons por Ressonância Magnética , Relação Estrutura-Atividade
10.
Nat Commun ; 11(1): 3135, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32561713

RESUMO

It is commonly thought that when multiple carbon sources are available, bacteria metabolize them either sequentially (diauxic growth) or simultaneously (co-utilization). However, this view is mainly based on analyses in relatively simple laboratory settings. Here we show that a heterotrophic marine bacterium, Pseudoalteromonas haloplanktis, can use both strategies simultaneously when multiple possible nutrients are provided in the same growth experiment. The order of nutrient uptake is partially determined by the biomass yield that can be achieved when the same compounds are provided as single carbon sources. Using transcriptomics and time-resolved intracellular 1H-13C NMR, we reveal specific pathways for utilization of various amino acids. Finally, theoretical modelling indicates that this metabolic phenotype, combining diauxie and co-utilization of substrates, is compatible with a tight regulation that allows the modulation of assimilatory pathways.


Assuntos
Carbono/metabolismo , Processos Heterotróficos/fisiologia , Modelos Biológicos , Pseudoalteromonas/fisiologia , Biomassa , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Meios de Cultura/metabolismo , Cinética , Espectroscopia de Prótons por Ressonância Magnética
11.
PLoS Biol ; 18(6): e3000728, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32516311

RESUMO

The development of multicellularity is a key evolutionary transition allowing for differentiation of physiological functions across a cell population that confers survival benefits; among unicellular bacteria, this can lead to complex developmental behaviors and the formation of higher-order community structures. Herein, we demonstrate that in the social δ-proteobacterium Myxococcus xanthus, the secretion of a novel biosurfactant polysaccharide (BPS) is spatially modulated within communities, mediating swarm migration as well as the formation of multicellular swarm biofilms and fruiting bodies. BPS is a type IV pilus (T4P)-inhibited acidic polymer built of randomly acetylated ß-linked tetrasaccharide repeats. Both BPS and exopolysaccharide (EPS) are produced by dedicated Wzx/Wzy-dependent polysaccharide-assembly pathways distinct from that responsible for spore-coat assembly. While EPS is preferentially produced at the lower-density swarm periphery, BPS production is favored in the higher-density swarm interior; this is consistent with the former being known to stimulate T4P retraction needed for community expansion and a function for the latter in promoting initial cell dispersal. Together, these data reveal the central role of secreted polysaccharides in the intricate behaviors coordinating bacterial multicellularity.


Assuntos
Myxococcus xanthus/citologia , Myxococcus xanthus/metabolismo , Polissacarídeos Bacterianos/metabolismo , Acetilação , Vias Biossintéticas/genética , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Membrana Celular/metabolismo , Família Multigênica , Myxococcus xanthus/genética , Polissacarídeos Bacterianos/química , Espectroscopia de Prótons por Ressonância Magnética , Tensoativos/metabolismo
12.
Int J Nanomedicine ; 15: 3539-3550, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32547012

RESUMO

Background: Methotrexate (MTX) is an antiproliferative drug widely used to treat inflammatory diseases and autoimmune diseases. The application of percutaneous administration is hindered due to its poor transdermal penetration. To reduce side effects and enhanced percutaneous delivery of MTX, novel methotrexate (MTX)-loaded micelles prepared with a amphiphilic cationic material, N,N-dimethyl-(N',N'-di-stearoyl-1-ethyl)1,3-diaminopropane (DMSAP), was designed. Materials and Methods: DMSAP was synthesized via three steps using simple chemical agents. H nuclear magnetic resonance and mass spectroscopy were used to confirm the successful synthesis of DMSAP. A safe and non-toxic phosphatidylcholine, soybean phosphatidylcholine (SPC), was added to DMSAP at different ratios to form P/D-micelles. Then, MTX-entrapped micelles (M/P/D-micelles) were prepared by electrostatic adsorption. The physicochemical properties and blood stability of micelles were examined thoroughly. In addition, the transdermal potential of the micelles was evaluated by permeation experiments. Results: In aqueous environments, DMSAP conjugates could self-assemble spontaneously into micelles with a low critical micelle concentration (CMC) of 0.056 mg/mL. Stable, spherical MTX-entrapped micelles (M/P/D-micelles) with a size of 100-120 nm and high zeta potential of +36.26 mV were prepared. In vitro permeation studies showed that M/P/D-micelles exhibited superior skin permeability and deposition of MTX in the epidermis and dermis compared with that of free MTX. Conclusion: These special novel cationic M/P/D-micelles can enhance the permeability of MTX and are expected to be a promising percutaneous delivery system for therapy skin diseases.


Assuntos
Metotrexato/administração & dosagem , Micelas , Administração Cutânea , Animais , Cátions , Bovinos , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Humanos , Metotrexato/química , Camundongos , Concentração Osmolar , Tamanho da Partícula , Fosfatidilcolinas/química , Espectroscopia de Prótons por Ressonância Magnética , Soroalbumina Bovina/química , Pele/efeitos dos fármacos , Eletricidade Estática
13.
Zhongguo Zhong Yao Za Zhi ; 45(9): 2186-2192, 2020 May.
Artigo em Chinês | MEDLINE | ID: mdl-32495570

RESUMO

Proton nuclear magnetic resonance(~1H-NMR) is used to investigate the effect of Renshenjian Decoction on serum and urine metabolism of type 2 diabetic rats with insulin resistance induced by high-sugar and high-fat diet combined with low-dose streptozotocin(STZ). After the successful establishment of the insulin resistance model of type 2 diabetes, administration for 35 days, the serum and urine of rats were taken. Once the ~1H-NMR data have been collected and processed, PCA and OPLS-DA were used to analyze them. The results show that: compared with the blank group, the contents of methionine, taurine, α-glucose and ß-glucose in the serum of the model group increased significantly(P<0.001), while the contents of 3-hydroxybutyric acid, lactic acid and unsaturated fatty acids decreased significantly(P<0.01). In the model group, the contents of trimethylamine oxide, glycine, α-glucose, ß-glucose, taurine and phosphocholine in urine increased significantly(P<0.05), while the contents of creatine, lactic acid, acetic acid and citric acid decreased significantly(P<0.05). Compared with the model group, the contents of 3-hydroxybutyric acid and unsaturated fatty acids in serum of rats in the treatment group increased significantly(P<0.05), while the contents of taurine, α-glucose and ß-glucose decreased significantly(P<0.01). In the treatment group, the contents of lactic acid, taurine and creatine in urine increased significantly(P<0.05), while the contents of trimethylamine oxide, glycine, α-glucose, ß-glucose and phosphocholine decreased significantly(P<0.01). The results show that Renshenjian Decoction can regulate metabolic disorder and promote the metabolic phenotype to return to the normal range. It displayed therapeutic effect on type 2 diabetic rats with insulin resistance and provided a certain scientific basis for the biological basic research of Renshenjian Decoction by improving insulin resistance in diabetes mellitus.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Animais , Glicemia , Metabolômica , Espectroscopia de Prótons por Ressonância Magnética , Ratos , Ratos Sprague-Dawley
14.
Food Chem ; 331: 127278, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32569965

RESUMO

1H quantitative Nuclear Magnetic Resonance (qNMR) spectroscopy technique has certain advantages such as low-temperature operation, authentic structural prediction and short data acquisition time. In this study, a 1H qNMR method was developed for the analysis of propenylbenzenes (eugenol and seven analogues) in the essential oils, a broadly distributed class of natural flavours. It was validated in terms of specificity (methoxy/acetate signal), linearity (range 0.05-5.00 mg per assay), sensitivity (limit of detection and quantification 4.4 and 14.9 µg/mL respectively), accuracy and precision. The qNMR technique was utilized during the sensory or activity-guided identification of chavibetol as the key odorant and antioxidant in the betel (Piper betle L., Bangla cultivar) oil, a widely consumed chewing stimulant and valuable flavouring agent. The method was also applied for the evaluation of six different post-harvest drying techniques for betel leaves through the quantitative analysis of unambiguously identified propenylbenzene markers (chavibetol, chavibetol acetate and 4-allyl-1,2-phenylene diacetate).


Assuntos
Antioxidantes/análise , Odorantes/análise , Óleos Voláteis/análise , Piper betle/química , Espectroscopia de Prótons por Ressonância Magnética/métodos , Benzeno/análise , Benzeno/química , Dessecação , Eugenol/análogos & derivados , Eugenol/análise , Humanos , Limite de Detecção , Micro-Ondas , Óleos Voláteis/química , Folhas de Planta/química , Reprodutibilidade dos Testes
15.
Food Chem ; 331: 127351, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32580126

RESUMO

We processed three quinoa ecotypes as they are commonly consumed in a daily diet. For the treatments, quinoa seeds were washed, cooked, and/or germinated. Following treated, we used 1H NMR-based metabolomic profiling to explore differences between the ecotypes. Then, for a non-targeted and targeted food fingerprint analysis of samples, we performed multivariable data analyses, including principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and hierarchical cluster analysis. From our study, we were able to discriminate each quinoa ecotype regardless of treatment based on its metabolomic profiling. Additionally, we were able to identify 30 metabolites that were useful to determine the effect of each treatment on nutritional composition. Germination increased the content of most metabolites irrespective of ecotype. In general, ecotype CQE_03 was different from ecotypes CQE_01 and CQE_02. Our phytochemical analysis revealed the effects of washing, cooking, and/or germination, particularly on saponins content.


Assuntos
Chenopodium quinoa/química , Chenopodium quinoa/crescimento & desenvolvimento , Metabolômica/métodos , Espectroscopia de Prótons por Ressonância Magnética/métodos , Chenopodium quinoa/metabolismo , Culinária , Análise Discriminante , Ecótipo , Equador , Germinação , Análise dos Mínimos Quadrados , Metabolômica/estatística & dados numéricos , Análise de Componente Principal , Espectroscopia de Prótons por Ressonância Magnética/estatística & dados numéricos , Sementes/química , Sementes/crescimento & desenvolvimento
16.
Food Chem ; 328: 126959, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32474235

RESUMO

This study presents a level-1 identification of the seven carbon (7-C) sugar C-methyl-scyllo-inositol (mytilitol) in mussels and clams (Mytilus and Ruditapes spp., respectively) purchased in Denmark and Italy. For each sample, the hydrophilic extract of the soft tissue was analyzed by proton nuclear magnetic resonance (1H NMR) spectroscopy using a 600 MHz NMR spectrometer. A first tentative identification of mytilitol was carried out by computing a statistical total correlation spectroscopy (STOCY) analysis of the 1H NMR spectra, followed by a level-1 identification based on first-principles methods including chemical synthesis, structure elucidation and standard-addition experiments. Mytilitol was quantified in the 1H NMR spectra and its average relative concentration turned out to be significantly lower in clams than in mussels (p-value < 0.001), with Danish mussels having the highest mytilitol concentration. Principal component analysis (PCA) of the NMR dataset brought further evidence to a species-specific and geographic-dependent content of mytilitol in mussels and clams.


Assuntos
Bivalves/metabolismo , Metaboloma , Mytilus/metabolismo , Animais , Análise de Componente Principal , Espectroscopia de Prótons por Ressonância Magnética , Especificidade da Espécie
17.
J Chromatogr A ; 1621: 461081, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32349863

RESUMO

The chemical composition distribution (CCD) of three single site made ethylene/1-octene copolymers was investigated through offline-hyphenation of solvent gradient interaction chromatography (SGIC) with 1H NMR. Thus, a clear, non-linear correlation between SGIC elution time and chemical composition was found under the specific measurement conditions applied here. The application of 1H NMR as detection allowed to determine the CCD with unprecedented accuracy. 2D-LC of the copolymers revealed the correlation between CCD and molar mass distribution (MMD) in a quantitative manner. Furthermore, this approach allowed a comparison between the response behavior of an evaporative light scattering detector (ELSD, semi-quantitative, commonly applied in SGIC) and that of an infrared (IR) detector (quantitative, commonly applied in SEC). As a result, it could be shown that ELSD results are close to IR results for the system investigated here, in other words, the often-criticized semi-quantitative response behavior of the ELSD is affecting results in an acceptable manner.


Assuntos
Alcenos/análise , Cromatografia Líquida de Alta Pressão/métodos , Elastômeros/análise , Etilenos/análise , Polienos/análise , Calibragem , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Elastômeros/química , Peso Molecular , Espectroscopia de Prótons por Ressonância Magnética , Solventes/química , Temperatura , Fatores de Tempo
18.
Medicine (Baltimore) ; 99(19): e19909, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32384434

RESUMO

BACKGROUND: Panic disorder (PD), defined by repeated and unexpected panic attacks, severely affects patients' living quality and social function. Perimenopausal women are high-risk group of PD and suffer greatly from it. Modern medicine therapies for this disorder have many side reactions and poor effects, so nonpharmacological modality is an urgent need. Although acupoint catgut embedding is widely used in clinical practice, there is no persuasive evidence of its effect for perimenopausal PD. The aim of this study is to investigate the effectiveness and safety of acupoint catgut embedding for perimenopausal PD and to elucidate the correlations among brain neural activation, bio-markers (amino acids) and clinical outcomes with radiographic evidence, thus to explore its neural mechanism. METHODS: The parallel designed, exploratory randomized controlled trial will include 70 outpatients with perimenopausal PD recruited from two hospitals of Chinese Medicine. These subjects will be randomly allocated to an intervention group (Group Embedding) and a control group (Group Medication) in a 1:1 ratio. The subjects in the intervention group will receive acupoint catgut embedding treatment two weeks a time in the following predefined acupuncture points: Shenshu (BL23), Sanyinjiao (SP6), Guanyuan (RN4), Ganshu (BL18), Zusanli (ST36) and Pishu (BL20). The included women of the control group will take 0.4 mg Alprazolam tablet orally, 1 tablet a time, 3 times a day. There is a study period of 3 months and a follow-up period of 1 month for each group. The primary outcomes will be the following therapeutic indexes: the frequency of panic attack, Panic Disorder Severity Score (PDSS), and Panic-associated Symptoms Score (PASS) during the observation period and follow-up period. The changes in Hamilton Anxiety Scale (HAMA) Score and Symptom Checklist 90 (SCL-90) Score will also be compared between these two groups. Additionally, functional magnetic resonance imaging (fMRI) and proton magnetic resonance spectroscopy (1H-MRS) scans will be done before and after the observation period to show cranial neuroimaging changes. DISCUSSION: We present a study design and rationale to explore the effectiveness and neural mechanism of acupoint catgut embedding for perimenopausal PD. There are still several factors restrict our research such as no unified standard of diagnostic criteria and curative effect evaluation. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR-INR-16009724, registered in November 2016.


Assuntos
Pontos de Acupuntura , Categute , Transtorno de Pânico/terapia , Perimenopausa , Adulto , Biomarcadores/análise , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Feminino , Humanos , Imagem por Ressonância Magnética , Pessoa de Meia-Idade , Neuroimagem/métodos , Transtorno de Pânico/diagnóstico por imagem , Transtorno de Pânico/fisiopatologia , Espectroscopia de Prótons por Ressonância Magnética , Ensaios Clínicos Controlados Aleatórios como Assunto , Índice de Gravidade de Doença , Resultado do Tratamento
19.
Phytochemistry ; 176: 112401, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32464510

RESUMO

Psiadia arguta (Asteraceae) is endemic to the island of Mauritius in the Indian Ocean. The species is traditionally used to treat various ailments, such as its use as an expectorant or for the treatment of bronchitis and asthma. Preliminary biological screenings have displayed the antimalarial (Plasmodium falciparum) and anticancer (HeLa human cell line) potential of P. arguta leaves. The phytochemical investigation of this plant has led to the isolation and characterization of sixteen compounds including five antiplasmodial molecules. The accumulation of the antiplasmodial compounds during the growth of the plant was studied by a 1H NMR-based metabolomic approach. In order to identify factors influencing the production of bioactive compounds, young plants of P. arguta were multiplied using in vitro culture techniques, and micro-propagated plants at different stages of development were acclimatized and followed for the experiments. The multivariate data analysis showed an accumulation of four bioactive compounds in the leaves of P. arguta when these plants were challenged with a biotic stress: labdan-13(E)-en-8α-ol-15-yl acetate, labdan-8α-ol-15-yl acetate, labdan-13(E)-ene-8α-ol-15-diol, and (8R,13S)-labdan-8,15-diol.


Assuntos
Antimaláricos , Asteraceae , Humanos , Extratos Vegetais , Folhas de Planta , Plasmodium falciparum , Espectroscopia de Prótons por Ressonância Magnética
20.
Int J Nanomedicine ; 15: 2987-2998, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32431497

RESUMO

Background: Emerging cancer therapy requires highly sensitive diagnosis in combination with cancer-targeting therapy. In this study, a self-assembled pH-sensitive curcumin (Cur)-loaded nanoparticle of 99mTc radiolabeled hyaluronan-cholesteryl hemisuccinate conjugates (HA-CHEMS) and D-a-tocopheryl polyethylene glycol succinate (TPGS) was prepared for breast cancer synergistic theranostics. Materials and Methods: The synthesized amphiphilic HA-CHEMS conjugates and TPGS self-assembled into Cur-loaded nanoparticles (HA-CHEMS-Cur-TPGS NPs) in an aqueous environment. The physicochemical properties of HA-CHEMS-Cur-TPGS NPs were characterized by transmission electron microscopy (TEM) and dynamic lighter scattering (DLS). The in vitro cytotoxicity of HA-CHEMS-Cur-TPGS NPs against breast cancer cells was evaluated by using the methyl thiazolyl tetrazolium (MTT) assay. Moreover, the in vivo animal experiments of HA-CHEMS-Cur-TPGS NPs including SPECT/CT imaging biodistribution and antitumor efficiency were investigated in 4T1 tumor-bearing BALB/c mice; furthermore, pharmacokinetics were investigated in healthy mice. Results: HA-CHEMS-Cur-TPGS NPs exhibited high curcumin loading, uniform particle size distribution, and excellent stability in vitro. In the cytotoxicity assay, HA-CHEMS-Cur-TPGS NPs showed remarkably higher cytotoxicity to 4T1 cells with an IC50 value at 38 µg/mL, compared with free curcumin (77 µg/mL). Moreover, HA-CHEMS-Cur-TPGS NPs could be effectively and stably radiolabeled with 99mTc. The SPECT images showed that 99mTc-HA-CHEMS-Cur-TPGS NPs could target the 4T1 tumor up to 4.85±0.24%ID/g at 4 h post-injection in BALB/c mice. More importantly, the in vivo antitumor efficacy studies showed that HA-CHEMS-Cur-TPGS NPs greatly inhibited the tumor growth without resulting in obvious toxicities to major organs. Conclusion: The results indicated that HA-CHEMS-Cur-TPGS NPs with stable 99mTc labeling and high curcumin-loading capacity hold great potential for breast cancer synergistic theranostics.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Curcumina/uso terapêutico , Ácido Hialurônico/química , Nanopartículas/química , Tecnécio/química , Nanomedicina Teranóstica , alfa-Tocoferol/química , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Curcumina/farmacocinética , Curcumina/farmacologia , Feminino , Humanos , Camundongos Endogâmicos BALB C , Nanopartículas/ultraestrutura , Tamanho da Partícula , Polietilenoglicóis/química , Espectroscopia de Prótons por Ressonância Magnética , Distribuição Tecidual/efeitos dos fármacos
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