13c Nmr
Mostrando 1-12 de 837 artigos, teses e dissertações.
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1. Two Woody Scented Oils from the Amazonian Forest
The essential oils from Aniba parviflora and the balsam from Protium rubrum, which are two woody scented Amazonian species, were analyzed by gas chromatography-mass spectrometry (GC-MS), 1H and 13C nuclear magnetic resonance (NMR). GC-MS analysis revealed the presence of unknown constituents. These compounds were then isolated, analyzed and characterized by
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Synthesis and Biological Evaluation of Novel 1,3-Benzoxathiol-2-one Sulfonamides against Toxic Activities of the Venom of Bothrops jararaca and Bothrops jararacussu Snakes
This work describes the synthesis of new 1,3-benzoxathiol-2-one sulfonamides and evaluation of their ability to inhibit some in vitro (coagulant, proteolytic and hemolytic) and in vivo (hemorrhagic, edematogenic and lethality) toxic activities of Bothrops jararaca and Bothrops jararacussu venoms. Compounds have been synthesized from the coupling of intermedi
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Development of a TD-NMR Method to Monitor Brazil Nuts Oil Content: A Green and Low-Cost Based Approach
Growth in the international popularity of Brazil nuts oil (Bertholletia excelsa, Bonpl.) has demanded a closer look at quality aspects of the nuts. In this context, time-domain 1H nuclear magnetic resonance spectroscopy (TD-NMR) can be a useful tool for assessing the lipid portion of such matrices. In this work, a TD-NMR method was developed and validated to
J. Braz. Chem. Soc.. Publicado em: 2021-07
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4. Synthesis of Triazoles by Electro-Assisted Click Reaction Using a Copper Foil Electrode
This paper presents an innovative pathway for the synthesis of triazoles using the well-known “click chemistry” assisted by the electrochemical oxidation of metallic Cu0. The click reaction is used to couple a wide range of biological interest compounds. In this case, faster and less polluting methods for a biological environment was achived by in situ C
J. Braz. Chem. Soc.. Publicado em: 2021-07
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5. Electrochemical Preparation and Evaluation of Cytotoxic Activity of Methoxyl-oxo-biseugenol, a New Oxidized Derivative of Biseugenol
Electrochemical procedures have emerged as a powerful tool for the synthesis of complex organic molecules including transformation of natural products. In this study, the electrosynthesis of biseugenol in MeOH afforded one new oxidized derivative, which was characterized as methoxyl-oxo-biseugenol (MOB) by nuclear magnetic resonance (NMR) and electrospray io
J. Braz. Chem. Soc.. Publicado em: 2021-05
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6. Synthesis, in silico Study and Antileishmanial Evaluation of New Selenides Derived from 7-Chloro-quinoline and N-Phenylacetamides
This study describes a virtual screening performed for two series of selenides (28 compounds), derived from N-phenylacetamides chlorides and 7-chloro-quinoline, to determine their potential for leishmanicidal activity against Leishmania amazonensis and Leishmania donovani. Seven compounds were predicted as potential leishmanicides; therefore, they were synth
J. Braz. Chem. Soc.. Publicado em: 2021-04
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7. Efficient Synthesis and Antimicrobial Activities of Long Alkyl Chain Trifluoromethyl-1H-pyrazol-1-(thio)carboxamides and Trifluoromethyl-1H-pyrazol-1-yl-thiazoles
The synthesis of 3-alkyl-5-trifluoromethyl-1H- pyrazole-1-carboxamides, 3-alkyl-5-trifluoromethyl-1H-pyrazole-1-thiocarboxamides, and 2-(3-alkyl-5-trifluoromethyl-1H-pyrazol-1-yl)-thiazoles derivatives are reported. [3 + 2] cyclocondensations for a series of long alkyl chain 1,1,1-trifluoro-4-methoxyalk-3-en-2-ones and semicarbazide or thiosemicarbazide were
J. Braz. Chem. Soc.. Publicado em: 2021-04
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8. Synthesis, Spectroscopic Characterization, DFT Calculations and Preliminary Antifungal Activity of New Piperine Derivatives
Four new piperine derivatives, PC1-PC4, were synthesized, and their structures were fully characterized by infrared (IR) and 1H and 13C nuclear magnetic resonance (NMR) spectroscopies. Quantum chemical calculations were performed using density functional theory (DFT) with the B3LYP-D3/6-31G(d,p) and 6-311+G(2d,p) basis sets. Electronic properties, such as th
J. Braz. Chem. Soc.. Publicado em: 2021-03
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9. Preparation of Poly(3-hydroxybutyrate-b-ε-caprolactone) by Reactive Extrusion and Production of Electrospun Fibrous Mats
Poly(3-hydroxybutyrate) (PHB) has been proposed to be a potential candidate to be used as biomaterial. However, its poor processability, high brittleness and rigidity have limited its applicability. Transesterification reactions with poly(ε-caprolactone) (PCL), one of the most promising biomedical materials, emerge as an attractive alternative to improve it
J. Braz. Chem. Soc.. Publicado em: 2021-02
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10. Aqueous Extract of Cumaru (Dipteryx odorata) Seeds as Corrosion Inhibitor for Mild Steel in Hydrochloric Acid Solution
The corrosion inhibition of mild steel by aqueous extract of cumaru (Dipteryx odorata) seeds and its high molecular weight fraction (HMWF) was investigated in 1 mol L-1 HCl solution. The study was carried out through gravimetric essays, open circuit potential measurements, anodic and cathodic polarization curves and electrochemical impedance analyses, as wel
J. Braz. Chem. Soc.. Publicado em: 2021-02
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11. INSIGHT INTO THE CONFORMATIONAL SPACE OF N-BENZYL-N-(FURAN-2-YLMETHYL)ACETAMIDE BY NMR SPECTROSCOPY AND DFT CALCULATIONS
In this study, the conformational behavior of N-benzyl-N-(furan-2-ylmethyl) acetamide in chloroform was addressed by using a combined experimental/theoretical strategy using NMR spectroscopy and quantum chemical calculations. The 1H and 13C one-dimensional NMR spectra, as well as the two-dimensional HSQC-DEPT and HMBC-DEPT NMR spectra, evinced the presence o
Quím. Nova. Publicado em: 2021-01
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12. Evaluation of Lignins of Trunk and Roots from Citrus sinensis L. Osbeck: A Large Available Brazilian Biomass
Citrus biomass is a source of biobased products and presents extensive chemical diversity. Among the structural macromolecules, lignins have been used in resins, bioplastics, and nanoencapsulation. Brazil has a large source of lignins, which are orange trees removed from groves that need to be renewed. However, the knowledge about these lignins is limited an
J. Braz. Chem. Soc.. Publicado em: 2021-01