Consulta: subjectFacets:"NMR"
Registros recuperados: 13
Data/hora: 06/06/2024 07:27:06

New applications of low field NMR in soil science.
Provedor de dados: 14
Autores: NOVOTNY, E. H.; GALVOSAS, P.
Despite the wide application of low field NMR in different fields, from petrophysics to food science and industry, its use in Soil Science is still inconspicuous. To demonstrate opportunities for low field NMR in this area we will present a few examples of so far unpublished new applications of this powerful and more affordable technique in Soil Science
Tipo: Artigo de divulgação na mídia (INFOTECA-E)
Palavras-chave: NMR; Espectroscopia por ressonância magnética nuclear; Solo; Pedologia; Soil science; Nuclear magnetic resonance spectroscopy.
Ano: 2020
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1127172

Cytotoxic and Anti-Inflammatory Effects of Ent-Kaurane Derivatives Isolated from the Alpine Plant Sideritis hyssopifolia
Provedor de dados: 5
Autores: Aimond, Axelle; Calabro, Kevin; Audoin, Coralie; Olivier, Elodie; Dutot, Mélody; Buron, Pauline; Rat, Patrice; Laprévote, Olivier; Prado, Soizic; Roulland, Emmanuel; Thomas, Olivier P.; Genta-jouve, Grégory.
This paper reports the isolation and structural characterization of four new ent-kaurane derivatives from the Lamiaceae plant Sideritis hyssopifolia. Planar structures and relative configurations were determined using both mass spectrometry and nuclear magnetic resonance (1D and 2D). Absolute configurations were determined by comparing experimental and theoretical electronic circular dichroism spectra. The cytotoxic and microbial activities of all new compounds were tested. Compounds that were non-cytotoxic were further evaluated for anti-inflammatory activity.
Tipo: Text
Palavras-chave: Sideritis hyssopifolia; Ent-kaurane; Anti-inflammatory; NMR.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00610/72214/71012.pdf

Métabolisme énergétique du spermatozoïde d'huître creuse (Crassostrea gigas)
Provedor de dados: 5
Autores: Boulais, Myrina.
The present study aims at describing the energy metabolism of Pacific oyster, Crassostrea gigas, spermatozoon. The main objectives are: (1) describing the kinetic of cellular and biochemical characteristics of Pacific oyster spermatozoon during its movement phase, (2) identifying the metabolic pathways to produce energy and their substrates, (3) determining the involvement of energy metabolism in fertilization success. The results showed the long duration (ranging 24 to 72h) of the movement of Pacific oyster spermatozoon and the maintenance of a high intracellular ATP content until the end of the movement phase. The role of oxidative phosphorylation (OXPHOS) in ATP production was highlighted. Alternative ATP producing pathways might contribute to sustain...
Tipo: Text
Palavras-chave: Fécondation; Sperme; Analyse du mouvement; Métabolisme énergétique; RMN; Cytométrie en flux; Crassostrea gigas; Reproduction; Fertilization; Sperm; Movement analysis; Energetic metabolism; NMR; Flow cytometry.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00498/60940/64334.pdf

A di-O-dihydrogeranylgeranyl glycerol from Thermococus S 557, a novel ether lipid, and likely intermediate in the biosynthesis of diethers in Archaea
Provedor de dados: 5
Autores: Gonthier, Isabelle; Rager, Marie-noëlle; Metzger, Pierre; Guezennec, Jean; Largeau, Claude.
The lipids of a deep-sea hydrothermal vent arch ae on, Thermococcus S 557, were isolated, purified and structurally determined. Based on acid methanolysis and spectroscopic studies, the polar lipids were shown to comprise diphytanyl glycerol and dibiphytanyl diglycerol, typical membrane lipids of Arch aea. From the neutral lipids, 2,3-di-O-dihydro-14,15-geranylgeranyl glycerol was isolated. This novel ether lipid is, very likely, a close intermediate in the biosynthesis of diphytanyl glycerol diether in Arch aea.
Tipo: Text
Palavras-chave: Mass spectrometry; NMR; Novel glycerol diether lipid; Thermococcus sp; Archaea.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/publication-736.pdf

Structure Elucidation, Relative LC–MS Response and In Vitro Toxicity of Azaspiracids 7–10 Isolated from Mussels (Mytilus edulis)
Provedor de dados: 5
Autores: Kilcoyne, Jane; Twiner, Michael J.; Mccarron, Pearse; Crain, Sheila; Giddings, Sabrina D.; Foley, Barry; Rise, Frode; Hess, Philipp; Willdns, Alistair L.; Miles, Christopher O.
Azaspiracids (AZAs) are marine biotoxins produced by dinoflagellates that can accumulate in shellfish, which if consumed can lead to poisoning events. AZA7–10, 7–10, were isolated from shellfish and their structures, previously proposed on the basis of only LC–MS/MS data, were confirmed by NMR spectroscopy. Purified AZA4–6, 4–6, and 7–10 were accurately quantitated by qNMR and used to assay cytotoxicity with Jurkat T lymphocyte cells for the first time. LC–MS(MS) molar response studies performed using isocratic and gradient elution in both selected ion monitoring and selected reaction monitoring modes showed that responses for the analogues ranged from 0.3 to 1.2 relative to AZA1, 1. All AZA analogues tested were cytotoxic to Jurkat T lymphocyte cells in a...
Tipo: Text
Palavras-chave: Azaspiracid; Structure confirmation; LC-MS molar response; NMR; Mass spectrometry; Purification; Jurkat T; Toxicity.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00269/38059/36190.pdf

NMR Structure of rALF-Pm3, an Anti-Lipopolysaccharide Factor from Shrimp: Model of the Possible Lipid A-Binding Site
Provedor de dados: 5
Autores: Yang, Yinshan; Boze, Helene; Chemardin, Patrick; Padilla, Andre; Moulin, Guy; Tassanakajon, Anchalee; Pugniere, Martine; Roquet, Francoise; Destoumieux Garzon, Delphine; Gueguen, Yannick; Bachere, Evelyne; Aumelas, Andre.
The anti-lipopolysaccharide factor ALF-Pm3 is a 98-residue protein identified in hemocytes from the black tiger shrimp Penaeus monodon. It was expressed in Pichia pastoris from the constitutive glyceraldehyde-3-phosphate dehydrogenase promoter as a folded and N-15 uniformly labeled rALF-Pm3 protein. Its 3D structure was established by NMR and consists of three alpha-helices packed against a four-stranded beta-sheet. The C-34-C-55 disulfide bond was shown to be essential for the structure stability. By using surface plasmon resonance, we demonstrated that rALF-Pm3 binds to LPS, lipid A and to OM(R)-174, a soluble analogue of lipid A. Biophysical studies of rALF-Pm3/LPS and rALF-Pm3/OM(R)-174 complexes indicated rather high molecular sized aggregates, which...
Tipo: Text
Palavras-chave: Ultracentrifugation; Surface plasmon resonance; Septic shock; Structure; NMR; Lipid A; Lipopolysaccharide; Anti lipopolysaccharide factor.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6320.pdf

NMR structure of mussel mytilin, and antiviral-antibacterial activities of derived synthetic peptides
Provedor de dados: 5
Autores: Roch, Philippe; Yang, Y; Toubiana, Mylene; Aumelas, A.
Mytilin is a 34-residue antibacterial peptide from the mussel Mytilus galloprovincialis, which in addition possesses in vitro antiviral activity. The three-dimensional solution structure of the synthetic mytilin was established by using 1H NMR and consists of the common cysteine-stabilized alpha beta motif close to the one observed in the mussel defensin MGD-1. Mytilin is characterized by 8 cysteines engaged in four disulfide bonds (2-27, 6-29, 10-31, and 15-34) only involving the beta-strand II. Hydrophilic and hydrophobic areas of mytilin account for 63% and 37%, respectively, a ratio very close to that of MGD-1 (64% and 36%). One linear and three cyclic fragments were designed from the interstrand loop sequence known to retain the biological activities...
Tipo: Text
Palavras-chave: Shrimp; Molluscs; Mussel; Antibacterial activity; WSSV; Viral protection; Beta hairpin structure; NMR; Mytilin; Antimicrobial peptide.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4485.pdf

NMR relaxometry as a potential non-invasive routine sensor for characterization of phenotype in Crassostrea gigas
Provedor de dados: 5
Autores: Davenel, Armel; Pouvreau, Stephane; Cambert, Mireille; Suquet, Marc; Mariette, Francois.
MR imaging is the most appropriate non-invasive technique for quantifying the growth of somatic and gonad tissues and to determine sex in the Pacific oyster, Crassostrea gigas. However, this technique is too costly for field studies where oysters are used as bioindicators of environmental quality or to be applied routinely in hatcheries. We have tested the ability of low Nuclear Magnetic Resonance relaxometry, a much less expensive technique, to obtain phenotype parameters that can be used to monitor the physiological state of oysters. NMR measurements were carried out at three different periods using a low field spectrometer equipped with a 50 mm diameter probe to investigate 60 oysters in their first year of maturity, which were then dissected to measure...
Tipo: Text
Palavras-chave: Sex identification; Growth; NMR; Crassostrea gigas; Phenotype characterization.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6456.pdf

Analysis of Water in the Chicken Eggshell Using the 1H Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy
Provedor de dados: 89
Autores: Szeleszczuk,Ł; Pisklak,DM; Wawer,I.
ABSTRACT The water content of the chicken eggshell has a major influence on gas (CO2 and O2) permeability. Inappropriate water loss during the incubation period increases embryo mortality and decreases chick quality. So far only the procedures that enable to determine the total water content in the eggshell have been described and developed. Our analysis of the 1H MAS NMR spectra of the chicken eggshell samples revealed three signals, differing significantly in the chemical shift and relaxation times (T1) parameters. In this work we have assigned those signals and described the changes in their intensities that occur during the incubation period. Using 1H MAS NMR it is possible to distinguish two types of water reservoirs in the chicken eggshell. This...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Water; Chicken eggshell; NMR; Incubation.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2016000600027

Complete assignments of NMR data and assessment of trypanocidal activity of new eremantholide C derivatives
Provedor de dados: 42
Autores: SAÚDE-GUIMARÃES,DÊNIA A.; RASLAN,DÉLIO S.; CHIARI,EGLER; OLIVEIRA,ALAÍDE B. DE.
Chemical transformations of eremantholide C (1), a sesquiterpene lactone that was isolated from Lychnophora trichocarpha Spreng. led to five new derivatives: 1′,2′- epoxyeremantholide C (2), 5-n-propylamine-4,5-dihydro-1′,2′-epoxyeremantholide C (3), 5-n-propylammonium-4,5-dihydro-1′,2′-epoxyeremantholide C chloride (4), 5-n-propylammonium-4,5-dihydroeremantolide C chloride (5) and 16-O-ethyleremantholide C (6). The structures of all these derivatives were assigned on the basis of IR, MS, 1H and 13C NMR data by 1D and 2D techniques. Eremantholide C and the derivatives 2, 4 and 5 were evaluated against trypomastigotes Y and CL strains of Trypanosoma cruzi. Eremantholide C completely inhibited the growth of both the parasites strains while all derivatives...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Eremantholide C derivatives; Lychnophora trichocarpha; NMR; Sesquiterpene lactones; Trypanocidal activity.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000401563

Methylation-GC-MS analysis of arabinofuranose- and galactofuranose-containing structures: rapid synthesis of partially O-methylated alditol acetate standards
Provedor de dados: 42
Autores: Sassaki,Guilherme L.; Iacomini,Marcello; Gorin,Philip A.J.
Arabinose and galactose were treated with MeOH containing traces of H2SO4 or HCl at 25ºC to give mixtures of their methyl alpha- and beta-furanosides, as shown by 1D and 2D nuclear magnetic resonance (NMR). Oxidation of the Me alpha,beta-Araf mixture with NaIO4 preferentially oxidised the beta-isomer, to give pure Me alpha-Araf . Each product was progressively O-methylated using the Purdie reagent (MeI/Ag2O) at 25ºC and resulting mixtures of partially methylated glycosides (PMGs) were rapidly assayed by thin layer chromatography (TLC) first to favour higher yields of mono-O-methyl derivatives and later for products with higher degrees of methylation. The products were converted to complex mixtures of partially O-methylated alditol acetate derivatives...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Partially O-methylated alditol acetates; GC-MS standards; Purdie methylation; OH reactivity; NMR.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652005000200003

Multivariate analysis of the spectroscopic profile of the sugar fraction of apple pomace
Provedor de dados: 52
Autores: Gabriel,Luciana Sutil; Prestes,Rosilene Aparecida; Pinheiro,Luís Antonio; Barison,Andersson; Wosiacki,Gilvan.
Pomace, the main by-product of apple juice processing, contains all the fruit's compounds such as minerals, sugars, fibers, enzymes and secondary metabolites after bioprocessing. Dried pomace from four apple varieties (Gala, Fuji, Catarina and Joaquina) was used to extract fructose, glucose, and sucrose, the main soluble sugars contained in apple pomace, to verify the possible use of the sugar fractions. The concentrated sugars were characterized by NMR and FTIR. The partial least squares method (PLS) applied to the NMR and FTIR spectra revealed large amounts of fructose, glucose, and sucrose, without the presence of others compounds. Principal component analysis (PCA) discriminated the studied apple varieties, with a 99% level of significance, as function...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Apple pomace; NMR; FTIR; Multivariate analysis.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132013000300012

Metabolomics as a promising tool for early osteoarthritis diagnosis
Provedor de dados: 56
Autores: de Sousa,E.B.; dos Santos Junior,G.C.; Duarte,M.E.L.; Moura Neto,V.; Aguiar,D.P.
Osteoarthritis (OA) is the main cause of disability worldwide, due to progressive articular cartilage loss and degeneration. According to recent research, OA is more than just a degenerative disease due to some metabolic components associated to its pathogenesis. However, no biomarker has been identified to detect this disease at early stages or to track its development. Metabolomics is an emerging field and has the potential to detect many metabolites in a single spectrum using high resolution nuclear magnetic resonance (NMR) techniques or mass spectrometry (MS). NMR is a reproducible and reliable non-destructive analytical method. On the other hand, MS has a lower detection limit and is more destructive, but it is more sensitive. NMR and MS are useful...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: NMR; Metabolomics; Osteoarthritis; Synovial Fluid.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2017001100301