Magnetic Circular Dichroism
Mostrando 1-12 de 95 artigos, teses e dissertações.
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1. Dextran Sulfate/Pramlintide Polyelectrolyte Nanoparticles as a Promising Delivery System: Optimization, Evaluation of Supramolecular Interactions and Effect on Conformational Stability of the Peptide Drug
In this study, we investigated the feasibility to obtain nanoparticles (NPs) by assembling pramlintide (Pram) with dextran sulfate (DexS), as a new approach for mucosal peptide delivery. DexS/Pram NPs were prepared by dropwise addition of a Pram solution to a DexS solution under magnetic stirring. The physicochemical characteristics of NPs and molecular inte
J. Braz. Chem. Soc.. Publicado em: 2021-08
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2. Isolation, Absolute Configuration and Cytotoxic Activities of Alkaloids from Hippeastrum goianum (Ravenna) Meerow (Amaryllidaceae)
The phytochemical study of Hippeastrum goianum led to the identification of 13 compounds by means of gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). Compounds 7-demethoxy-9-O-methylhostasine (1) and 7-deoxi-trans-dihydronarciclasine (2) had their absolute configurations determined by vibrational circular dichroism (VCD). Th
J. Braz. Chem. Soc.. Publicado em: 2020-10
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3. Absolute Configuration of (−)-Cubebin, a Classical Lignan with Pharmacological Potential, Defined by Means of Chiroptical Spectroscopy
This work describes the first determination of the absolute configuration (AC) of (−)-cubebin by means of electronic circular dichroism (ECD), supported by quantum chemical calculations. The comparison of experimental ECD with the corresponding quantum chemical prediction for the proper diastereoisomer resulted in the definitive assignment of the AC of the
J. Braz. Chem. Soc.. Publicado em: 2020-10
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4. A New Isoflavone and Other Constituents from Roots of Clitoria guianensis
A new isoflavone named pratensein-7-O-β-D-rutinoside [(-)-7-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl-5,3’-dihydroxy-4’-methoxyisoflavone] and the known compounds biochanin A-7-O-β-D-rutinoside, 6-deoxyclitoriacetal 11-O-β-D-glucopyranoside, 6-deoxyclitoriacetal, (2S)-naringenin-6-C-β-D-glucopyranoside, (2R)-naringenin-6-C-β-D-glucopyranosi
J. Braz. Chem. Soc.. Publicado em: 2020-08
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5. Antimicrobial Diterpene from the Brazilian Termite Nasutitermes macrocephalus (Isoptera: Termitidae: Natutitermitinae)
Termites are insects with a complex social organization on castes among which soldiers are the only responsible for the colony defense. The soldiers of the Nasutitermes genus use chemical defense, which comprises a mixture of mono, sesqui and mainly diterpenes. The new diterpene 2b,3a-dihydroxy-trinervita-1(15),11-diene, found in Nasutitermes macrocephalus,
J. Braz. Chem. Soc.. Publicado em: 2018-03
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6. Butyrolactones from the Endophytic Fungus Aspergillus versicolor and their Anti-Tobacco Mosaic Virus Activity
New butyrolactones aspernolides C and D, along with two known butyrolactones (A and B) were isolated from the culture of the endophytic fungus Aspergillus versicolor. Their structures were elucidated on the basis of extensive spectroscopic analysis, including 1D and 2D nuclear magnetic ressonance techniques, and electronic circular dichroism. The butyrolacto
J. Braz. Chem. Soc.. Publicado em: 2015-03
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7. Estudos biofísicos de chaperonas de secreção e de interações proteína-ligante / Biophysical studies on secretion chaperones and protein-ligand interactions
So far, the Xanthomonas axonopodis pv. citri (XAC) mechanisms of bacterial virulence is unknown. It is believed that secretion chaperones (CS) are involved in the XAC´s virulence process by first forming complexes with virulence factors, and assisting in their presentation to corresponding secretion systems using ATP as a source of energy. Fluorescence emis
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/03/2012
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8. Estudos da correlação estrutura-função da enzima Clorocatecol 1,2-Dioxigenase de Pseudomonas putida / Studies of the structure-function correlation of the chlorocatechol 1,2-dioxygenase enzyme from Pseudomonas putida
O intenso uso de compostos orgânicos em conjunto com o grande avanço industrial culminou em um enorme acúmulo de poluentes orgânicos no meio ambiente. Dentre estes poluentes têm-se destacado a presença de hidrocarbonetos aromáticos altamente tóxicos e resistentes à degradação física, química, fotolítica e biológica. Desta maneira, uma nova for
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 13/02/2012
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9. Estudos da dinâmica estrutural da proteína ligante de cálcio S100A12 humana e da lisozima T4 / Structural dynamics studies of human calcium binding protein S100A12 and T4 lysozyme
The work presented here was conceived with two main objectives. The first one, more general, involved the implementation of a new methodology for the study of conformational changes in proteins, i.e., its structural dynamics. The technique of Site-directed Spin Labeling combined with Electronic Paramagnetic Resonance (SDSL-EPR) are the pillars of this new me
Publicado em: 2011
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10. Study of the magnetic properties of AuPd nanoparticles / Estudo das propriedades magneticas de nanoparticulas de AuPd
Nanopartículas (NPs) metálicas, filmes ultrafinos e sistemas nano-estruturados têm motivado vários estudos teóricos e experimentais devido a novas propriedades eletrônicas, óticas e magnéticas destes materiais. Nas NPs, tais propriedades estão diretamente relacionadas aos efeitos de tamanho (size effect) e superfície, os quais afetam suas estrutura
Publicado em: 2008
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11. Magnetic circular dichroism instrumentation at LNLS
We describe the high-field (1.0 T) ultra high vacuum (1.6 10- 9 mbar) controllable temperature (8 ºK up to > 350ºK) MCD setup designed and built at LNLS. We show, for nanocrystals of Hematite alpha-Fe2O3, illustrative results obtained at room and at low temperature.
Brazilian Journal of Physics. Publicado em: 2007-09
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12. Strutural characterization of hypothetical proteins complex - XACb0032/XACb0033 from Xanthomonas axonopodis pv. citri / Caracterização estrutural do complexo de proteinas hipoteticas - XACb0032/XACb0033 da bacteria Xanthomonas axonopodis pv. citri
Xanthomonas axonopodis pv. citri (Xac) is the causative agent of citrus canker, a disease of significant economic importance worldwide. The molecular bases of the virulence mechanism are still unknown, but is believed that transfer of bacterial virulence proteins directly into the host cell cytoplasm is mediated by protein secretion systems, mainly type III
Publicado em: 2007