Spectroscopic Methods
Mostrando 1-12 de 235 artigos, teses e dissertações.
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1. Synthesis, Characterization, Absorption and Fastness Properties of Novel Monoazo Dyes Derived from 1-Phenyl-3-amino-4-(2-thiazolilazo)pyrazol-5-one
Monosubstitute thiazolyl amines were diazotized in acetic acid, coupled to 1-phenyl-3-aminopyrazol-5-one (1a-1c) and acetylated to obtain the 2a-2c dyes. The dyes were characterized by elemental analysis and spectroscopic (Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), ultraviolet (UV)) methods. The effects on the visible absorption spe
J. Braz. Chem. Soc.. Publicado em: 2020-09
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2. TÉCNICAS AVANÇADAS PARA A DIFERENCIAÇÃO DE ISÔMEROS POR ESPECTROMETRIA DE MASSAS
Mass spectrometry (MS) is a powerful and widespread technique but is inherently uncapable to differentiate species with same m/z ratio. For this reason, many classical approaches were developed based on differential fragmentation patterns in tandem MS. More recently, new techniques for isomer identification in MS were developed, and we highlight the photodis
Quím. Nova. Publicado em: 2020-09
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3. Antibacterial Activity of 2-Amino-1,4-naphthoquinone Derivatives against Gram-Positive and Gram-Negative Bacterial Strains and Their Interaction with Human Serum Albumin
A series of 2-amino-1,4-naphthoquinone derivatives (NQA-NQF) was synthesized by alternative methods (ultrasonication and microwave irradiation), with yields ranging from 40 to 71%, and without the need of further recrystallization. Each compound was evaluated against four Gram-positive (Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus and Baci
J. Braz. Chem. Soc.. Publicado em: 2020-09
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4. VIBRATIONAL SPECTROSCOPIC INVESTIGATION AND MOLECULAR STRUCTURE OF A 5α-REDUCTASE INHIBITOR: FINASTERIDE
By way of Density Functional Theory (DFT)-based computational methods with commercially available software, the computational work of which about the molecular properties, the vibrational modes and vibrational frequencies of finasteride were accomplished for the first time. In order to gain a deeper and more thorough understanding of the molecular structure
Quím. Nova. Publicado em: 2020-05
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5. Theoretical and Experimental Investigations on Inclusion Complex β-Cyclodextrin and Sulcatone: A Cardiovascular Activity Evaluation
In this paper, we have applied state-of-the-art technologies and new investigations were developed focusing on obtaining simple and inexpensive molecules for treating cardiovascular diseases, as they are considered the leading cause of death in the world. For the first time, the inclusion complex of sulcatone (SU) and β-cyclodextrin (β-CD) was achieved (us
J. Braz. Chem. Soc.. Publicado em: 2020-05
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6. 3-Aminofurostane Alkaloids from Solanum paniculatum (“Jurubeba Verdadeira”) Roots
The roots of Solanum paniculatum (Solanaceae) have extensively been used in folk medicine to treat liver infections and as a diuretic. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) were used for the profiling and structural characterization of alkaloids from the roots of S. paniculatum. Six
J. Braz. Chem. Soc.. Publicado em: 2020-05
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7. Chemical constituents from the fruits of Schisandra sphenanthera and their cytotoxicity activity
Abstract Schisandra sphenanthera Rehder & E.H. Wilson, Schisandraceae, is well known as a type of traditional medicine for the treatment of hepatitis, diarrhea and insomnia in Asia. It was also reported to have antiviral and anti-HIV activities. Using various chromatographic resins and isolation techniques, a new lignan (1), erythro-4-(3,4-dimethoxyphenyl)-4
Rev. bras. farmacogn.. Publicado em: 09/12/2019
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8. A New Tetraglycosylated Flavonoid from Leaves of Platycyamus regnellii Benth. Isolated by High-Speed Countercurrent Chromatography
A new tetraglycosylated flavonoid derivative of kaempferol was isolated from the butanol extract of leaves of Platycyamus regnellii (Fabaceae) using high-speed countercurrent chromatography (HSCCC). The butanol extract (960.5 mg) was initially fractionated with the solvent system EtOAC-BuOH-H2O 2:8:10 (v/v/v) (elution in normal phase mode). The fractions con
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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9. Identification of compounds from chufa (Eleocharis dulcis) peels with inhibitory acrylamide formation activity
Abstract Five compounds were isolated from the peels of chufa (Eleocharis dulcis (Burm.f.) Trin. ex Hensch., Cyperaceae). The chemical structures were determined by various spectroscopic analysis methods, including 1D and 2D NMR, and by comparison with literature data. All compounds were isolated for the first time from the peels of chufa. Compounds orcinol
Rev. bras. farmacogn.. Publicado em: 17/10/2019
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10. In vitro Antiplasmodial Activities of Alkaloids Isolated from Roots of Worsleya procera (Lem.) Traub (Amaryllidaceae)
A combined phytochemical, crystallographic and biological study of Worsleya procera roots was performed. Fifteen alkaloids were identified by gas chromatography mass spectrometry (GC-MS) and seven of them were isolated. The structures of the alkaloids were elucidated by spectroscopic methods, and a detailed crystallographic study of tazettine was carried out
J. Braz. Chem. Soc.. Publicado em: 12/08/2019
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11. AlradSpectra: a Quantification Tool for Soil Properties Using Spectroscopic Data in R
ABSTRACT Soil reflectance spectroscopy has become an innovative method for soil property quantification supplying data for studies in soil fertility, soil classification, digital soil mapping, while reducing laboratory time and applying a clean technology. This paper describes the implementation of a Graphical User Interface (GUI) using R named AlradSpectra.
Rev. Bras. Ciênc. Solo. Publicado em: 29/07/2019
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12. Chronic hypoglycemic effect and phytochemical composition of Smilax moranensis roots
ABSTRACT Smilax moranensis M.Martens & Galeotti, Smilacaceae, root is a medicinal plant used among the Chatinos in Oaxaca, Mexico, to control type 2 diabetes. The objectives of the study were to isolate the bioactive compounds from the roots of Smilax and evaluate the chronic hypoglycemic effect of the ethanol–water extract. The main compounds were isolate
Rev. bras. farmacogn.. Publicado em: 27/05/2019