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| Registros recuperados: 28 | |
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| 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 |
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| 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 |
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| HAYES, M. H. B.; NOVOTNY, E. H.; FLANAGAN, R.. |
| NMR provides a powerful tool for studies of compositions of Biochars. However, the usual NMR procedures used for humic and SOM studies do not meet specific requirements for Biochars because pyrogenic materials present strong local magnetic susceptibility heterogeneities. Our data show that uses of CSA-filter and TOSS techniques make the pulse sequences very sensitive to imperfections in the pulses. We will show how we have used Variable Amplitude CP - (VACP)/MAS spectra and composite pulses in the CSA-filter and TOSS pulse sequences. In that way the component functionalities in a humic acid (HA) from a Terra Preta soil were successfully determined. Other techniques will be discussed. |
| Tipo: Anais e Proceedings de eventos |
Palavras-chave: NMR; Terra preta de índio; Soil organic matter; Biochar. |
| Ano: 2008 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/339823 |
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| 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 |
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| CONTE, P.; DE PASQUALE, C.; NOVOTNY, E. H.; CAPONETTO, G.; LAUDICINA, V. A.; CIOFALO, M.; PANNO, M.; PALAZZOLO, E.; BADALUCCO, L.; ALONZO, G.. |
| Reafforestation is generally based on the planting of exotic fast growing tree species suitable for adapting to even harsh environments. Once the introduced plants ameliorate soil conditions, they can be progressively replaced by au- tochthonous plant species. Reafforestation is applied worldwide. However, only few studies on the effect of reafforesta- tion on lands from Mediterranean regions are available. This paper reports the characterization by cross polarization 13C NMR spectroscopy of fresh leaves and superficial litters from a reafforestated area in central Sicily (Italy). NMR assign- ment is attempted. A differentiation among the molecular systems within leaves and litters is also done on the basis of NMR assessment. Results showed that the main... |
| Tipo: Artigo de periódico |
Palavras-chave: NMR; Litters; Reafforestation; Solo; Degradação Ambiental; Leaves. |
| Ano: 2010 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/873852 |
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| 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 |
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| 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 |
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| 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 |
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| Registros recuperados: 28 | |
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