Infrared Spectrometry
Mostrando 13-24 de 272 artigos, teses e dissertações.
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13. 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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14. 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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15. Identification of Synthetic Drugs on Seized Blotter Papers Using ATR-FTIR and PLS-DA: Routine Application in a Forensic Laboratory
Blotter papers seizures containing synthetic drugs have intensified over the last decades. These drugs were originally conceived as “legal” alternatives to traditional illicit drugs, designed to mimic their effects and circumvent control agencies. Reference methods for determining these substances on blotter papers are based on chromatographic techniques
J. Braz. Chem. Soc.. Publicado em: 2021-03
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16. A new polysaccharide isolated from Dendrobium offcinale, stimulates aquaporin-3 expression in human keratinocytes
Abstract Polysaccharides are the major components of the water extract from Dendrobium officinale, which have been thoroughly studied and found to have favorable moisturizing properties on mammalian skin. However, the structures of polysaccharides on skin moisturizing properties remains unknown. The aim of this study was to extract and characterize D. offici
Food Sci. Technol. Publicado em: 2021-03
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17. Synthesis, Characterization and Exchange Reactions of Layered Double Hydroxides of Copper and Aluminum, Intercalated with Sulfate
Layered double hydroxides (LDHs) of Cu:Al in the molar ratio of 2:1, intercalated with sulfate, sulfate/(Li+, Na+, K+ or NH4+), NO3- and CO32-, were synthesized by co-precipitation with increasing pH. The materials were submitted to exchange reactions using B2SO4 (B = Li+, Na+, K+, NH4+) solutions in an attempt to replace previously intercalated cations or i
J. Braz. Chem. Soc.. Publicado em: 2021-01
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18. EXTRACTION AND IDENTIFICATION OF FORMULATIONS OF ANABOLIC ANDROGENIC STEROIDS: A FORENSIC EDUCATIONAL APPROACH
The use of anabolic androgenic steroids is largely restricted worldwide since they are associated with innumerous side effects and health damage. However, apprehensions of formulations of anabolic agents have been extensively increasing throughout the world, making their analysis a common task in the forensic field. In this sense, a set of three experiments
Quím. Nova. Publicado em: 2020-12
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19. Hybrid Hydrogels Based on Polyethylene Glycol Bioconjugated with Silylated-Amyloidogenic Peptides
Hybrid-peptide hydrogel arrangements are a promising alternative to obtaining biocompatible structures at the nanoscopic scale. In this work, a new class of hybrid hydrogels was obtained through the sol-gel process based on the reaction between an amyloid-like octapeptide sequence [RF]4 (where R = arginine and F = phenylalanine) covalently bonded with glycin
J. Braz. Chem. Soc.. Publicado em: 2020-11
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20. Synthesis, in silico Study, Theoretical Stereochemistry Elucidation and Antifungal Activity of New Imides Derived from Safrole
Ten imides derived from safrole, 4a-4j, were synthesized and their structures were fully characterized by infrared (IR) spectroscopy, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry (HRMS) analysis. Among the ten imides studied, eight are new. The compounds were evaluated in an in silico study and showed strong
J. Braz. Chem. Soc.. Publicado em: 2020-10
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21. IN SITU DRIFTS/MS STUDIES ON THE INTERACTION OF METHANOL AND ETHYL ACETATE OVER MG-LA CATALYST
The surface intermediates formed on the Mg-La catalyst (molar ratio 1:1) were studied through temperature-programmed desorption (TPD) and diffuse reflectance infrared Fourier transform spectroscopy coupled to mass spectrometry (DRIFTS-MS) using methanol (MeOH) and ethyl acetate (EA) as probe molecules. TPD results showed that the products formed from adsorbe
Quím. Nova. Publicado em: 2020-09
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22. 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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23. Combined Analytical Py-GC/MS, SEM, FTIR and 13C NMR for Investigating the Removal of Trace Metals from Aqueous Solutions by Biochar
In this study, the efficiency of biochar (BC) produced from sugarcane bagasse at different pyrolysis temperatures (300, 400, 500 and 600 ºC) for simultaneous removal of CdII, PbII, CuII, CrIII, NiII and ZnII ions from aqueous solutions was assessed. All BC were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), 13C nu
J. Braz. Chem. Soc.. Publicado em: 2020-07
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24. Pyrolysis of the Caupi Bean Pod (Vigna unguiculata): Characterization of Biomass and Bio-Oil
The use of agricultural residues for the production of bio-oil is an important alternative to the use of fossil fuels. In this study, the Caupi bean pod (Vigna unguiculata) was characterized and used as biomass in the production of bio-oil. This biomass was evaluated in terms of physicochemical, morphological (scanning electron microscopy (SEM)), and thermal
J. Braz. Chem. Soc.. Publicado em: 2020-06