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1.
Neurology ; 97(8): e803-e813, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34426551

RESUMO

OBJECTIVE: To evaluate progressive cerebral degeneration in amyotrophic lateral sclerosis (ALS) by assessing alterations in N-acetylaspartate (NAA) ratios in the motor and prefrontal cortex within clinical subgroups of ALS. METHODS: Seventy-six patients with ALS and 59 healthy controls were enrolled in a prospective, longitudinal, multicenter study in the Canadian ALS Neuroimaging Consortium. Participants underwent serial clinical evaluations and magnetic resonance spectroscopy at baseline and 4 and 8 months using a harmonized protocol across 5 centers. NAA ratios were quantified in the motor cortex and prefrontal cortex. Patients were stratified into subgroups based on disease progression rate, upper motor neuron (UMN) signs, and cognitive status. Linear mixed models were used for baseline and longitudinal comparisons of NAA metabolite ratios. RESULTS: Patients with ALS had reduced NAA ratios in the motor cortex at baseline (p < 0.001). Ratios were lower in those with more rapid disease progression and greater UMN signs (p < 0.05). A longitudinal decline in NAA ratios was observed in the motor cortex in the rapidly progressing (p < 0.01) and high UMN burden (p < 0.01) cohorts. The severity of UMN signs did not change significantly over time. NAA ratios were reduced in the prefrontal cortex only in cognitively impaired patients (p < 0.05); prefrontal cortex metabolites did not change over time. CONCLUSIONS: Progressive degeneration of the motor cortex in ALS is associated with more aggressive clinical presentations. These findings provide biological evidence of variable spatial and temporal cerebral degeneration linked to the disease heterogeneity of ALS. The use of standardized imaging protocols may have a role in clinical trials for patient selection or subgrouping. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that MRS NAA metabolite ratios of the motor cortex are associated with more rapid disease progression and greater UMN signs in patients with ALS. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov Identifier: NCT02405182.


Assuntos
Esclerose Amiotrófica Lateral/metabolismo , Ácido Aspártico/análogos & derivados , Disfunção Cognitiva/metabolismo , Progressão da Doença , Espectroscopia de Ressonância Magnética , Córtex Motor/metabolismo , Córtex Pré-Frontal/metabolismo , Adulto , Idoso , Esclerose Amiotrófica Lateral/complicações , Esclerose Amiotrófica Lateral/diagnóstico por imagem , Esclerose Amiotrófica Lateral/patologia , Ácido Aspártico/metabolismo , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/patologia , Feminino , Humanos , Estudos Longitudinais , Espectroscopia de Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Córtex Motor/diagnóstico por imagem , Córtex Motor/patologia , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/patologia , Índice de Gravidade de Doença
2.
Sci Rep ; 11(1): 16174, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376712

RESUMO

Oncostatin M (OSM) is a pleiotropic, interleukin-6 family inflammatory cytokine that plays an important role in inflammatory diseases, including inflammatory bowel disease, rheumatoid arthritis, and cancer progression and metastasis. Recently, elevated OSM levels have been found in the serum of COVID-19 patients in intensive care units. Multiple anti-OSM therapeutics have been investigated, but to date no OSM small molecule inhibitors are clinically available. To pursue a high-throughput screening and structure-based drug discovery strategy to design a small molecule inhibitor of OSM, milligram quantities of highly pure, bioactive OSM are required. Here, we developed a reliable protocol to produce highly pure unlabeled and isotope enriched OSM from E. coli for biochemical and NMR studies. High yields (ca. 10 mg/L culture) were obtained in rich and minimal defined media cultures. Purified OSM was characterized by mass spectrometry and circular dichroism. The bioactivity was confirmed by induction of OSM/OSM receptor signaling through STAT3 phosphorylation in human breast cancer cells. Optimized buffer conditions yielded 1H, 15N HSQC NMR spectra with intense, well-dispersed peaks. Titration of 15N OSM with a small molecule inhibitor showed chemical shift perturbations for several key residues with a binding affinity of 12.2 ± 3.9 µM. These results demonstrate the value of bioactive recombinant human OSM for NMR-based small molecule screening.


Assuntos
Descoberta de Drogas/métodos , Oncostatina M/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Sítios de Ligação , Linhagem Celular Tumoral , Humanos , Espectroscopia de Ressonância Magnética/métodos , Simulação de Acoplamento Molecular , Oncostatina M/química , Oncostatina M/metabolismo , Fosforilação , Ligação Proteica , Fator de Transcrição STAT3/metabolismo , Bibliotecas de Moléculas Pequenas/química
3.
Nat Commun ; 12(1): 4798, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376656

RESUMO

We describe the anaerobic conversion of inositol stereoisomers to propionate and acetate by the abundant intestinal genus Anaerostipes. A inositol pathway was elucidated by nuclear magnetic resonance using [13C]-inositols, mass spectrometry and proteogenomic analyses in A. rhamnosivorans, identifying 3-oxoacid CoA transferase as a key enzyme involved in both 3-oxopropionyl-CoA and propionate formation. This pathway also allowed conversion of phytate-derived inositol into propionate as shown with [13C]-phytate in fecal samples amended with A. rhamnosivorans. Metabolic and (meta)genomic analyses explained the adaptation of Anaerostipes spp. to inositol-containing substrates and identified a propionate-production gene cluster to be inversely associated with metabolic biomarkers in (pre)diabetes cohorts. Co-administration of myo-inositol with live A. rhamnosivorans in western-diet fed mice reduced fasting-glucose levels comparing to heat-killed A. rhamnosivorans after 6-weeks treatment. Altogether, these data suggest a potential beneficial role for intestinal Anaerostipes spp. in promoting host health.


Assuntos
Acetatos/metabolismo , Clostridiales/metabolismo , Inositol/metabolismo , Intestinos/química , Propionatos/metabolismo , Animais , Clostridiales/classificação , Clostridiales/fisiologia , Dieta , Fezes/microbiologia , Interações entre Hospedeiro e Microrganismos , Humanos , Intestinos/microbiologia , Espectroscopia de Ressonância Magnética/métodos , Masculino , Camundongos Endogâmicos C57BL , Ácido Fítico/metabolismo , Espectrometria de Massas em Tandem/métodos
4.
Molecules ; 26(12)2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34205539

RESUMO

This review outlines methods to investigate the structure of natural products with emphasis on intramolecular hydrogen bonding, tautomerism and ionic structures using NMR techniques. The focus is on 1H chemical shifts, isotope effects on chemical shifts and diffusion ordered spectroscopy. In addition, density functional theory calculations are performed to support NMR results. The review demonstrates how hydrogen bonding may lead to specific structures and how chemical equilibria, as well as tautomeric equilibria and ionic structures, can be detected. All these features are important for biological activity and a prerequisite for correct docking experiments and future use as drugs.


Assuntos
Produtos Biológicos/química , Preparações Farmacêuticas/química , Humanos , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética/métodos , Simulação de Acoplamento Molecular/métodos
5.
J Enzyme Inhib Med Chem ; 36(1): 1267-1281, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34210221

RESUMO

Mirolysin is a secretory protease of Tannerella forsythia, a member of the dysbiotic oral microbiota responsible for periodontitis. In this study, we show that mirolysin latency is achieved by a "cysteine-switch" mechanism exerted by Cys23 in the N-terminal profragment. Mutation of Cys23 shortened the time needed for activation of the zymogen from several days to 5 min. The mutation also decreased the thermal stability and autoproteolysis resistance of promirolysin. Mature mirolysin is a thermophilic enzyme and shows optimal activity at 65 °C. Through NMR-based fragment screening, we identified a small molecule (compound (cpd) 9) that blocks promirolysin maturation and functions as a competitive inhibitor (Ki = 3.2 µM), binding to the S1' subsite of the substrate-binding pocket. Cpd 9 shows superior specificity and does not interact with other T. forsythia proteases or Lys/Arg-specific proteases.


Assuntos
Peptídeo Hidrolases/metabolismo , Periodontite/microbiologia , Inibidores de Proteases/farmacologia , Tannerella forsythia/enzimologia , Proteínas de Bactérias/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Descoberta de Drogas , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática , Humanos , Espectroscopia de Ressonância Magnética/métodos , Simulação de Acoplamento Molecular , Estrutura Molecular , Peptídeo Hidrolases/efeitos dos fármacos , Inibidores de Proteases/química , Tannerella forsythia/isolamento & purificação , Temperatura
6.
Molecules ; 26(14)2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34299495

RESUMO

Bicuspid aortic valve (BAV) is the most common congenital heart defect responsible for valvular and aortic complications in affected patients. Causes and mechanisms of this pathology are still elusive and thus the lack of early detection biomarkers leads to challenges in its diagnosis and prevention of associated cardiovascular anomalies. The aim of this study was to explore the potential use of urine Nuclear Magnetic Resonance (NMR) metabolomics to evaluate a molecular fingerprint of BAV. Both multivariate and univariate statistical analyses were performed to compare the urinary metabolome of 20 patients with BAV with that of 24 matched controls. Orthogonal partial least squared discriminant analysis (OPLS-DA) showed statistically significant discrimination between cases and controls, suggesting seven metabolites (3-hydroxybutyrate, alanine, betaine, creatine, glycine, hippurate, and taurine) as potential biomarkers. Among these, glycine, hippurate and taurine individually displayed medium sensitivity and specificity by receiver operating characteristic (ROC) analysis. Pathway analysis indicated two metabolic pathways likely perturbed in BAV subjects. Possible contributions of gut microbiota activity and energy imbalance are also discussed. These results constitute encouraging preliminary findings in favor of the use of urine-based metabolomics for early diagnosis of BAV.


Assuntos
Doença da Válvula Aórtica Bicúspide/metabolismo , Doença da Válvula Aórtica Bicúspide/urina , Biomarcadores/urina , Metaboloma/fisiologia , Adolescente , Adulto , Idoso , Análise Discriminante , Feminino , Humanos , Análise dos Mínimos Quadrados , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Masculino , Redes e Vias Metabólicas/fisiologia , Metabolômica/métodos , Pessoa de Meia-Idade , Curva ROC , Adulto Jovem
7.
Molecules ; 26(14)2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34299514

RESUMO

Aspergillus is one of the most diverse genera, and it is chemically profound and known to produce many biologically active secondary metabolites. In the present study, a new aspochalasin H1 (1), together with nine known compounds (2-10), were isolated from a Hawaiian plant-associated endophytic fungus Aspergillus sp. FT1307. The structures were elucidated using nuclear magnetic resonance (NMR) (1H, 1H-1H COSY, HSQC, HMBC, ROESY and 1D NOE), high-resolution electrospray ionization mass spectroscopy (HRESIMS), and comparisons with the reported literature. The absolute configuration of the new compound was established by electronic circular dichroism (ECD) in combination with NMR calculations. The new compound contains an epoxide moiety and an adjacent trans-diol, which has not been reported before in the aspochalasin family. The antibacterial screening of the isolated compounds was carried out against pathogenic bacteria (Staphylococcus aureus, Methicillin-resistant S. aureus and Bacillus subtilis). The antiproliferative activity of compounds 1-10 was evaluated against human breast cancer cell lines (MCF-7 and T46D) and ovarian cancer cell lines (A2780).


Assuntos
Aspergillus/metabolismo , Boraginaceae/microbiologia , Citocalasinas/farmacologia , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dicroísmo Circular , Feminino , Hawaii , Humanos , Células MCF-7 , Espectroscopia de Ressonância Magnética/métodos , Neoplasias Ovarianas/tratamento farmacológico
8.
Molecules ; 26(14)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34299654

RESUMO

A tripodal Schiff base ligand, 2,4,6-Tris(4-carboxybenzimino)-1,3,5-triazine (MT) and its trinuclear Dy(III), Er(III), and Gd(III) complexes were synthesized. These were characterized using UV-visible, IR, 1H, and 13C NMR spectroscopies, elemental analysis, and molar conductivity measurements. The spectral studies indicate that the ligand is hexadentate and coordinates to the Ln(III) ions through the oxygen atoms of the carboxylic group. The trinuclear complexes were characterized as being bridged by carboxylate anions to the Dy(III), Er(III), and Gd(III) salen centers and displaying a coordination number of six. Biological studies revealed that MT is more active against the test micro-organisms relative to the trinuclear complexes. Acute toxicity studies revealed that MT is safe and has a wide range of effective doses (ED50). In vivo antimalarial studies indicate that MT could serve as an effective antimalarial agent since it has parasitemia inhibition of 84.02% at 50 mg/kg and 65.81% at 25 mg/kg, close to the value (87.22%) of the standard drug-Artesunate. Molecular docking simulation studies on the compounds against SARS-CoV-2 (6Y84) and E. coli DNA gyrase (5MMN) revealed effective binding interactions through multiple bonding modes. The binding energy calculated for Er(III)MT-6Y84 and Er(III)MT-5MMN complexes showed active molecules with the ability to inhibit SARS-CoV-2 and E. coli DNA gyrase.


Assuntos
Triazinas/química , Triazinas/farmacologia , Ânions/química , Ácidos Carboxílicos/química , Simulação por Computador , Complexos de Coordenação/química , Cristalografia por Raios X/métodos , Disprósio/química , Érbio/química , Gadolínio/química , Elementos da Série dos Lantanídeos/química , Ligantes , Espectroscopia de Ressonância Magnética/métodos , Simulação de Acoplamento Molecular , Estrutura Molecular , Bases de Schiff/química , Triazinas/síntese química
9.
Molecules ; 26(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34207949

RESUMO

BACKGROUND: Nanobodies, or VHHs, are derived from heavy chain-only antibodies (hcAbs) found in camelids. They overcome some of the inherent limitations of monoclonal antibodies (mAbs) and derivatives thereof, due to their smaller molecular size and higher stability, and thus present an alternative to mAbs for therapeutic use. Two nanobodies, Nb23 and Nb24, have been shown to similarly inhibit the self-aggregation of very amyloidogenic variants of ß2-microglobulin. Here, the structure of Nb23 was modeled with the Chemical-Shift (CS)-Rosetta server using chemical shift assignments from nuclear magnetic resonance (NMR) spectroscopy experiments, and used as prior knowledge in PONDEROSA restrained modeling based on experimentally assessed internuclear distances. Further validation was comparatively obtained with the results of molecular dynamics trajectories calculated from the resulting best energy-minimized Nb23 conformers. METHODS: 2D and 3D NMR spectroscopy experiments were carried out to determine the assignment of the backbone and side chain hydrogen, nitrogen and carbon resonances to extract chemical shifts and interproton separations for restrained modeling. RESULTS: The solution structure of isolated Nb23 nanobody was determined. CONCLUSIONS: The structural analysis indicated that isolated Nb23 has a dynamic CDR3 loop distributed over different orientations with respect to Nb24, which could determine differences in target antigen affinity or complex lability.


Assuntos
Anticorpos Monoclonais/química , Cadeias Pesadas de Imunoglobulinas/química , Espectroscopia de Ressonância Magnética/métodos , Ressonância Magnética Nuclear Biomolecular/métodos , Anticorpos de Domínio Único/química , Microglobulina beta-2/metabolismo , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/metabolismo , Humanos , Cadeias Pesadas de Imunoglobulinas/imunologia , Cadeias Pesadas de Imunoglobulinas/metabolismo , Elementos Estruturais de Proteínas , Anticorpos de Domínio Único/imunologia , Anticorpos de Domínio Único/metabolismo , Microglobulina beta-2/imunologia
10.
Molecules ; 26(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208349

RESUMO

A new 11 amino acid linear peptide named roseabol A (1) and the known compound 13-oxo-trans-9,10-epoxy-11(E)-octadecenoic acid (2) were isolated from the fungus Clonostachys rosea. Combined NMR and MS analysis revealed that roseabol A (1) contained amino acid residues characteristic of the peptaibol family of peptides such as isovaline, α-aminoisobutyric acid, hydroxyproline, leucinol, and an N-terminal isovaleric acid moiety. The amino acid sequence was established by a combination of NMR studies and tandem MS fragmentation analyses, and the absolute configurations of the constituent amino acids of 1 were determined by the advanced Marfey's method. Compound 2 showed inhibitory activity against Merkel cell carcinoma, a rare and difficult-to-treat type of skin cancer, with an IC50 value of 16.5 µM.


Assuntos
Antineoplásicos/farmacologia , Carcinoma de Célula de Merkel/tratamento farmacológico , Hypocreales/química , Peptaibols/química , Peptaibols/farmacologia , Neoplasias Cutâneas/tratamento farmacológico , Sequência de Aminoácidos , Antineoplásicos/química , Carcinoma de Célula de Merkel/química , Carcinoma de Célula de Merkel/metabolismo , Linhagem Celular Tumoral , Humanos , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular , Neoplasias Cutâneas/química , Neoplasias Cutâneas/metabolismo
11.
Molecules ; 26(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204550

RESUMO

Recently, considerable attention has been paid to Bombyx mori silk fibroin by a range of scientists from polymer chemists to biomaterial researchers because it has excellent physical properties, such as strength, toughness, and biocompatibility. These appealing physical properties originate from the silk fibroin structure, and therefore, structural determinations of silk fibroin before (silk I) and after (silk II) spinning are a key to make wider applications of silk. There are discrepancies about the silk I structural model, i.e., one is type II ß-turn structure determined using many solid-state and solution NMR spectroscopies together with selectively stable isotope-labeled model peptides, but another is α-helix or partially α-helix structure speculated using IR and Raman methods. In this review, firstly, the process that led to type II ß-turn structure by the authors was introduced in detail. Then the problems in speculating silk I structure by IR and Raman methods were pointed out together with the problem in the assignment of the amide I band in the spectra. It has been emphasized that the conformational analyses of proteins and peptides from IR and Raman studies are not straightforward and should be very careful when the proteins contain ß-turn structure using many experimental data by Vass et al. In conclusion, the author emphasized here that silk I structure should be type II ß-turn, not α-helix.


Assuntos
Fibroínas/química , Fibroínas/metabolismo , Seda/química , Animais , Bombyx/química , Proteínas de Insetos/química , Espectroscopia de Ressonância Magnética/métodos , Peptídeos/química , Conformação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Seda/metabolismo , Espectrofotometria Infravermelho/métodos , Análise Espectral Raman/métodos
12.
Molecules ; 26(12)2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34204651

RESUMO

The driving forces and conformational pathways leading to amphitropic protein-membrane binding and in some cases also to protein misfolding and aggregation is the subject of intensive research. In this study, a chimeric polypeptide, A-Cage-C, derived from α-Lactalbumin is investigated with the aim of elucidating conformational changes promoting interaction with bilayers. From previous studies, it is known that A-Cage-C causes membrane leakages associated with the sporadic formation of amorphous aggregates on solid-supported bilayers. Here we express and purify double-labelled A-Cage-C and prepare partially deuterated bicelles as a membrane mimicking system. We investigate A-Cage-C in the presence and absence of these bicelles at non-binding (pH 7.0) and binding (pH 4.5) conditions. Using in silico analyses, NMR, conformational clustering, and Molecular Dynamics, we provide tentative insights into the conformations of bound and unbound A-Cage-C. The conformation of each state is dynamic and samples a large amount of overlapping conformational space. We identify one of the clusters as likely representing the binding conformation and conclude tentatively that the unfolding around the central W23 segment and its reorientation may be necessary for full intercalation at binding conditions (pH 4.5). We also see evidence for an overall elongation of A-Cage-C in the presence of model bilayers.


Assuntos
Proteína Oncogênica pp60(v-src)/química , Fragmentos de Peptídeos/química , Peptídeos/química , Lactalbumina/química , Espectroscopia de Ressonância Magnética/métodos , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Membranas , Simulação de Dinâmica Molecular , Proteína Oncogênica pp60(v-src)/metabolismo , Fragmentos de Peptídeos/metabolismo , Peptídeos/metabolismo , Ligação Proteica , Conformação Proteica
13.
Molecules ; 26(13)2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34279429

RESUMO

Racemic ketoprofen (KP) and ß-cyclodextrin (ß-CD) powder samples from co-precipitation (1), evaporation (2), and heating-under-reflux (3) were analysed using X-ray techniques and nuclear magnetic resonance (NMR) spectroscopy. On the basis of NMR studies carried out in an aqueous solution, it was found that in the samples obtained by methods 1 and 2, there were large excesses of ß-CD in relation to KP, 10 and 75 times, respectively, while the sample obtained by method 3 contained equimolar amounts of ß-CD and KP. NMR results indicated that KP/ß-CD inclusion complexes were formed and the estimated binding constants were approximately 2400 M-1, showing that KP is quite strongly associated with ß-CD. On the other hand, the X-ray single-crystal technique in the solid state revealed that the (S)-KP/ß-CD inclusion complex with a stoichiometry of 2:2 was obtained as a result of heating-under-reflux, for which the crystal and molecular structure were examined. Among the methods used for the preparation of the KP/ß-CD complex, only method 3 is suitable.


Assuntos
Cetoprofeno/química , Espectroscopia de Ressonância Magnética/métodos , Difração de Raios X/métodos , beta-Ciclodextrinas/química , Estrutura Molecular
14.
Molecules ; 26(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34299389

RESUMO

Currently, most clinical studies in metabolomics only consider a single type of sample such as urine, plasma, or feces and use a single analytical platform, either NMR or MS. Although some studies have already investigated metabolomics data from multiple fluids, the information is limited to a unique analytical platform. On the other hand, clinical studies investigating the human metabolome that combine multi-analytical platforms have focused on a single biofluid. Combining data from multiple sample types for one patient using a multimodal analytical approach (NMR and MS) should extend the metabolome coverage. Pre-analytical and analytical phases are time consuming. These steps need to be improved in order to move into clinical studies that deal with a large number of patient samples. Our study describes a standard operating procedure for biological specimens (urine, blood, saliva, and feces) using multiple platforms (1H-NMR, RP-UHPLC-MS, and HILIC-UHPLC-MS). Each sample type follows a unique sample preparation procedure for analysis on a multi-platform basis. Our method was evaluated for its robustness and was able to generate a representative metabolic map.


Assuntos
Sangue/metabolismo , Fezes/química , Metaboloma , Saliva/química , Manejo de Espécimes/normas , Urina/química , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Espectroscopia de Ressonância Magnética/métodos
15.
Molecules ; 26(14)2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34299421

RESUMO

The quality of foods has led researchers to use various analytical methods to determine the amounts of principal food constituents; some of them are the NMR techniques with a multivariate statistical analysis (NMR-MSA). The present work introduces a set of NMR-MSA novelties. First, the use of a double pulsed-field-gradient echo (DPFGE) experiment with a refocusing band-selective uniform response pure-phase selective pulse for the selective excitation of a 5-10-ppm range of wine samples reveals novel broad 1H resonances. Second, an NMR-MSA foodomics approach to discriminate between wine samples produced from the same Cabernet Sauvignon variety fermented with different yeast strains proposed for large-scale alcohol reductions. Third a comparative study between a nonsupervised Principal Component Analysis (PCA), supervised standard partial (PLS-DA), and sparse (sPLS-DA) least squares discriminant analysis, as well as orthogonal projections to a latent structures discriminant analysis (OPLS-DA), for obtaining holistic fingerprints. The MSA discriminated between different Cabernet Sauvignon fermentation schemes and juice varieties (apple, apricot, and orange) or juice authentications (puree, nectar, concentrated, and commercial juice fruit drinks). The new pulse sequence DPFGE demonstrated an enhanced sensitivity in the aromatic zone of wine samples, allowing a better application of different unsupervised and supervised multivariate statistical analysis approaches.


Assuntos
Sucos de Frutas e Vegetais/análise , Espectroscopia de Ressonância Magnética/métodos , Metaboloma , Solventes/química , Vinho/análise
16.
Int J Mol Sci ; 22(14)2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34298936

RESUMO

Nuclear Magnetic Resonance (NMR) is a well-suited methodology to study bone composition and structural properties. This is because the NMR parameters, such as the T2 relaxation time, are sensitive to the chemical and physical environment of the 1H nuclei. Although magnetic resonance imaging (MRI) allows bone structure assessment in vivo, its cost limits the suitability of conventional MRI for routine bone screening. With difficulty accessing clinically suitable exams, the diagnosis of bone diseases, such as osteoporosis, and the associated fracture risk estimation is based on the assessment of bone mineral density (BMD), obtained by the dual-energy X-ray absorptiometry (DXA). However, integrating the information about the structure of the bone with the bone mineral density has been shown to improve fracture risk estimation related to osteoporosis. Portable NMR, based on low-field single-sided NMR devices, is a promising and appealing approach to assess NMR properties of biological tissues with the aim of medical applications. Since these scanners detect the signal from a sensitive volume external to the magnet, they can be used to perform NMR measurement without the need to fit a sample inside a bore of a magnet, allowing, in principle, in vivo application. Techniques based on NMR single-sided devices have the potential to provide a high impact on the clinical routine because of low purchasing and running costs and low maintenance of such scanners. In this review, the development of new methodologies to investigate structural properties of trabecular bone exploiting single-sided NMR devices is reviewed, and current limitations and future perspectives are discussed.


Assuntos
Doenças Ósseas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Absorciometria de Fóton/métodos , Animais , Densidade Óssea/fisiologia , Osso Esponjoso/diagnóstico por imagem , Fraturas Ósseas/diagnóstico por imagem , Humanos , Osteoporose/diagnóstico por imagem
17.
Int J Mol Sci ; 22(13)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34281189

RESUMO

Molecular modeling (MM) results for tedizolid and radezolid with heptakis-(2,3-diacetyl-6-sulfo)-ß-cyclodextrin (HDAS-ß-CD) are presented and compared with the results previously obtained for linezolid and sutezolid. The mechanism of interaction of chiral oxazolidinone ligands belonging to a new class of antibacterial agents, such as linezolid, tedizolid, radezolid, and sutezolid, with HDAS-ß-CD based on capillary electrokinetic chromatography (cEKC), nuclear magnetic resonance (NMR) spectroscopy, and MM methods was described. Principles of chiral separation of oxazolidinone analogues using charged single isomer derivatives of cyclodextrin by the cEKC method were presented, including the selection of the optimal chiral selector and separation conditions, complex stoichiometry, and binding constants, which provided a comprehensive basis for MM studies. In turn, NMR provided, where possible, direct information on the geometry of the inclusion complexes and also provided the necessary structural information to validate the MM calculations. Consequently, MM contributed to the understanding of the structure of diastereomeric complexes, the thermodynamics of complexation, and the visualization of their structures. The most probable mean geometries of the studied supramolecular complexes and their dynamics (geometry changes over time) were determined by molecular dynamics methods. Oxazolidinone ligands have been shown to complex mainly the inner part of cyclodextrin, while the external binding is less privileged, which is consistent with the conclusions of the NMR studies. Enthalpy values of binding of complexes were calculated using long-term molecular dynamics in explicit water as well as using molecular mechanics, the Poisson-Boltzmann or generalized Born, and surface area continuum solvation (MM/PBSA and MM/GBSA) methods. Computational methods predicted the effect of changes in pH and composition of the solution on the strength and complexation process, and it adapted the conditions selected as optimal during the cEKC study. By changing the dielectric constant in the MM/PBSA and MM/GBSA calculations, the effect of changing the solution to methanol/acetonitrile was investigated. A fairly successful attempt was made to predict the chiral separation of the oxazolidinones using the modified cyclodextrin by computational methods.


Assuntos
Oxazolidinonas/química , Tetrazóis/química , beta-Ciclodextrinas/química , Ciclodextrinas/química , Eletroforese Capilar/métodos , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Modelos Moleculares , Oxazolidinonas/metabolismo , Estereoisomerismo , Tetrazóis/metabolismo
18.
Molecules ; 26(11)2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34072383

RESUMO

Nuclear magnetic resonance (NMR) spectroscopy remains one of the core analytical platforms for metabolomics, providing complementary chemical information to others, such as mass spectrometry, and offering particular advantages in some areas of research on account of its inherent robustness, reproducibility, and phenomenal dynamic range [...].


Assuntos
Análise de Alimentos/métodos , Espectroscopia de Ressonância Magnética/métodos , Metabolômica/métodos , Animais , Cromatografia Líquida , Indústria Alimentícia , Tecnologia de Alimentos , Espectrometria de Massas/métodos , Carne/análise , Metaboloma , Análise Multivariada , Reprodutibilidade dos Testes , Solanum
19.
Molecules ; 26(11)2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34072445

RESUMO

Blastocystis is an opportunistic parasite commonly found in the intestines of humans and other animals. Despite its high prevalence, knowledge regarding Blastocystis biology within and outside the host is limited. Analysis of the metabolites produced by this anaerobe could provide insights that can help map its metabolism and determine its role in both health and disease. Due to its controversial pathogenicity, these metabolites could define its deterministic role in microbiome's "health" and/or subsequently resolve Blastocystis' potential impact in gastrointestinal health. A common method for elucidating the presence of these metabolites is through 1H nuclear magnetic resonance (NMR). However, there are currently no described benchmarked methods available to extract metabolites from Blastocystis for 1H NMR analysis. Herein, several extraction solvents, lysis methods and incubation temperatures were compared for their usefulness as an extraction protocol for this protozoan. Following extraction, the samples were freeze-dried, re-solubilized and analysed with 1H NMR. The results demonstrate that carrying out the procedure at room temperature using methanol as an extraction solvent and bead bashing as a lysis technique provides a consistent, reproducible and efficient method to extract metabolites from Blastocystis for NMR.


Assuntos
Blastocystis/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Metaboloma , Metabolômica/métodos , Liofilização , Metanol/química , Solubilidade , Solventes , Sonicação , Temperatura , Água/química
20.
AAPS PharmSciTech ; 22(5): 193, 2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34184163

RESUMO

The human immunodeficiency virus (HIV) impacts up to 37 million people globally, of which 1.8 million are children. To date, there is no cure for HIV, although treatment options such as antiretroviral therapy (ART) are available. ART, which involves a patient taking a combination of antiretrovirals, is being used to treat HIV clinically. Despite the effectiveness of ART, there is currently no palatable pediatric formulation to treat HIV in children, which has hindered patient compliance and overall treatment efficacy. In addition, anti-HIV therapeutics are often poorly water-soluble, and hence have poor bioavailability. In the present study, we developed a pediatric-friendly formulation for anti-HIV therapeutics with improved dissolution characteristics of the therapeutic agents. Lopinavir (LPV) and ritonavir (RTV), available as FDA-approved fixed-dose combination products, were chosen as model ART drugs, and the formulation and processing parameters of spray-dried cyclodextrin (CD)-based LPV and RTV complexes were studied. Results showed that the spray-dried complexes exhibited enhanced dissolution profiles in comparison to pure drugs, particularly spray-dried ß-CD complexes, which showed the most favorable dissolution profiles. This current formulation with enhanced dissolution and taste-masking ability through the use of cyclodextrin has the potential to address the unmet need for the development of suitable pediatric formulations.


Assuntos
Fármacos Anti-HIV/análise , Fármacos Anti-HIV/síntese química , Ciclodextrinas/análise , Ciclodextrinas/síntese química , Desenvolvimento de Medicamentos/métodos , Secagem por Atomização , Fármacos Anti-HIV/uso terapêutico , Criança , Ciclodextrinas/uso terapêutico , Composição de Medicamentos/métodos , Infecções por HIV/tratamento farmacológico , Humanos , Espectroscopia de Ressonância Magnética/métodos , Pediatria/métodos , Difração de Raios X/métodos
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