Nuclear Magnetic Resonance
Mostrando 13-24 de 1969 artigos, teses e dissertações.
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13. Agro-Industrial Waste Valorization: Transformation of Starch from Mango Kernel into Biocompatible, Thermoresponsive and High Swelling Nanogels
Mango industry processing disposes 40-60% of this fruit as residues, such as peels and kernels. The exploration of bioproducts from these industrial rejects can reduce environmental impact besides of producing high value-added materials. In this scenario, carboxymethyl starch nanoparticles were produced from mango (Mangifera indica L.) kernel starch. These n
J. Braz. Chem. Soc.. Publicado em: 2021-08
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14. 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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15. 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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16. Capital, ideologia e uma história do mundo sob o prisma da desigualdade
The phytochemical reinvestigation from the heartwood of the extracts of Cordia glazioviana led to the isolation of four still undescribed hydroquinones derivatives designated as cordiaquinol D (1), cordiaquinol E (2), (10R)-10,11-dihydrofuran-1,4-dihydroxy-globiferin (3) and 2-[(1’E,6’E)-3’,8’- dihydroxy-3’,7’-dimethylocta-1’,6’-dienyl]-benze
Econ. soc.. Publicado em: 2021-07
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17. Anti-Inflammatory Meroterpenoids of Cordia glazioviana (Boraginaceae)
The phytochemical reinvestigation from the heartwood of the extracts of Cordia glazioviana led to the isolation of four still undescribed hydroquinones derivatives designated as cordiaquinol D (1), cordiaquinol E (2), (10R)-10,11-dihydrofuran-1,4-dihydroxy-globiferin (3) and 2-[(1’E,6’E)-3’,8’- dihydroxy-3’,7’-dimethylocta-1’,6’-dienyl]-benze
J. Braz. Chem. Soc.. Publicado em: 2021-07
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18. A Greener Enzymatic Oligoesterification of Biobased Renewable Synthons
Polyesters of xylitol and succinic acid were prepared yielding from 70 to 75% by enzyme-catalyzed esterification using a molar mass from 1:1 to 2:5 at 120 and 140 °C employing from 1 to 10% m/m of enzyme. Control over branching degree was achieved by tuning the reaction conditions (temperature, time, comonomer ratio, enzyme content). This one-step process f
J. Braz. Chem. Soc.. Publicado em: 2021-06
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19. Direct steam injection pretreatment improves microwave-assisted extraction yield for total flavonoids and myricetin from Hovenia dulcis Thunb.
Abstract A direct steam injection pretreatment was added before the microwave-assisted extraction procedure for the extraction of flavonoids from seeds of Hovenia dulcis Thunb, and the antioxidant activity of flavonoid extracts was determined. Based on the experimental results, the addition of direct steam injection simultaneously increased the extraction yi
Food Sci. Technol. Publicado em: 2021-06
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20. Alcoholmeter as a Simple and Accessible Way for Ethanol Determination in Alcohol-Based Hand Sanitizers
Expensive and complex methodologies are available to determine the ethanol concentration in alcohol gel samples. The aim of this article was to demonstrate that alcoholmeter could be used as an alternative method to determine ethanol in gel formulations. Alcohol gel samples were produced using: hydroxypropylmethylcellulose (HPMC), hydroxyethylcellulose (HEC)
J. Braz. Chem. Soc.. Publicado em: 2021-06
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21. Optimization and Study of the Response Surface of Properties for the Synthesis of ZSM-5 Zeolites with Hierarchical Pore Structure Obtained by Desilication
Hierarchical ZSM-5 zeolites were prepared by alkali treatment (desilication) at two temperatures, two reaction times, and two NaOH concentrations. A 23 factorial design was used to study the effect of these variables on the crystallinity, microporosity, and mesoporosity of the zeolite due to the desilication treatment. The factorial design analysis showed th
J. Braz. Chem. Soc.. Publicado em: 2021-06
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22. Trypanocidal Activity and Increased Solubility of Benznidazole Incorporated in PEG 4000 and Its Derivatives
Selecting a polymer depends on its characteristics, the properties of the drug and of the remaining ingredients in the formulation. The drug, when incorporated into a polymeric matrix, can show several advantages when compared with its conventional form. In this context, this work describes the preparation and characterization of polyethylene glycol (PEG 400
J. Braz. Chem. Soc.. Publicado em: 2021-06
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23. Synthesis, Hypoglycemic Effect, Antimicrobial and Molecular Docking Studies of Organotin(IV) Complexes Derived From N-Phthalimido β-Amino Acid Derivatives
N-Phthalimido β-amino acid derivatives, 3-phthalimido-3(2-hydroxyphenyl) propanoic acid (P2HPA) and 3-phthalimido-3(2-nitrophenyl) propanoic acid (P2NPA) with new series of di- and triorganotin(IV) complexes (1-12) have been designed and synthesized. All the ligands and organotin(IV) complexes were characterized by elemental analysis, Fourier transform infr
J. Braz. Chem. Soc.. Publicado em: 2021-05
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24. 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