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1.
Int J Mol Sci ; 25(9)2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38732218

RESUMO

Boronate esters are a class of compounds containing a boron atom bonded to two oxygen atoms in an ester group, often being used as precursors in the synthesis of other materials. The characterization of the structure and properties of esters is usually carried out by UV-visible, infrared, and nuclear magnetic resonance (NMR) spectroscopic techniques. With the aim to better understand our experimental data, in this article, the density functional theory (DFT) is used to analyze the UV-visible and infrared spectra, as well as the isotropic shielding and chemical shifts of the hydrogen atoms 1H, carbon 13C and boron 11B in the compound 4-(4,4,5,5-tetramethyl-1,3,2-dioxoborolan-2-yl)benzaldehyde. Furthermore, this study considers the change in its electronic and spectroscopic properties of this particular ester, when its boron atom is coordinated with a fluoride anion. The calculations were carried out using the LSDA and B3LYP functionals in Gaussian-16, and PBE in CASTEP. The results show that the B3LYP functional gives the best approximation to the experimental data. The formation of a coordinated covalent B-F bond highlights the remarkable sensitivity of the NMR chemical shifts of carbon, oxygen, and boron atoms and their surroundings. Furthermore, this bond also highlights the changes in the electron transitions bands n → π* and π → π* during the absorption and emission of a photon in the UV-vis, and in the stretching bands of the C=C bonds, and bending of BO2 in the infrared spectrum. This study not only contributes to the understanding of the properties of boronate esters but also provides important information on the interactions and responses optoelectronic of the compound when is bonded to a fluorine atom.


Assuntos
Benzaldeídos , Benzaldeídos/química , Espectroscopia de Ressonância Magnética , Teoria da Densidade Funcional , Flúor/química , Boro/química , Modelos Moleculares , Ésteres/química , Espectrofotometria Infravermelho , Estrutura Molecular , Íons/química
2.
Materials (Basel) ; 16(8)2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-37109875

RESUMO

The use of computational methods that allow us to perform characterization on new compounds is not a novelty; nevertheless, the degree of complexity of the structures makes their study more challenging since new techniques and methods are required to adjust to the new structural model. The case of nuclear magnetic resonance characterization of boronate esters is fascinating because of its widespread use in materials science. In this paper, we use density functional theory to characterize the structure of the compound 1-[5-(4,5-Dimethyl-1,3,2-dioxaborolan-2-yl)thiophen-2-yl]ethanonea by means of nuclear magnetic resonance. We studied the compound in its solid form with the PBE-GGA and PBEsol-GGA functionals, with a set of plane wave functions and an augmented wave projector, which included gauge in CASTEP and its molecular structure with the B3LYP functional using the package Gaussian 09. In addition, we performed the optimization and calculation of the chemical shifts and isotropic nuclear magnetic resonance shielding of 1H, 13C, and 11B. Finally, we analyzed and compared the theoretical results with experimental diffractometric data observing a good approximation.

3.
Nat Prod Bioprospect ; 10(4): 221-225, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32504214

RESUMO

The methanol extract form the leaves of Phytolacca icosandra L., afforded the unprecedented artificial triterpenoid fatty acid ester 1 derived from the new natural triterpenoid phytolaccagenic acid 3-O-myristate (1a), along with the three known triterpenoids serjanic, acinosolic and phytolaccagenic acid (2 - 4). Their structures were stablished by HR-EI-MS, 1D and 2D NMR techniques. The possible mechanistic formation of 1 is proposed, and the in vitro toxicity of all compounds was assessed using the brine shrimp lethality assay (BSLA).

4.
Rev. biol. trop ; 66(2): 880-891, abr.-jun. 2018. graf
Artigo em Inglês | LILACS, SaludCR | ID: biblio-977352

RESUMO

Abstract Malaria represents a major health problem worldwide, affecting around 198 million people in 2016 according to WHO database. For decades, anti-malarial drug therapy has been used in the battle against this disease and its uncontrolled usage in endemic areas has developed the appearance of the drug resistance. Thus, it has emerged the necessity of finding new treatments that could be used as an alternative cure to malaria infection. The aim of this work was the evaluation of two photo-excitable compounds: Compound 1, which is (2E)-3-(4-dimethylamino-phenyl)-1-(4-imidazol-1-yl-phenyl)prop-2-en-1-one) and Compound 2, (1E,4E)1-[4-(dimethylamino)phenyl]-5-(4-methoxyphenyl)-1,4-pentadiene-3-one) as possible anti-malaria drugs with Plasmodium berghei ANKA strain in BALB/c mice as murine model. Cytotoxicity effect was evaluated by a cell proliferation by colorimetry assay (MTS); and the drug incorporation into the parasite was assessed in vitro with Indirect Immunofluorescence Assay (IFA) to determine the localization of the drugs into the parasitized red blood cells (RBCs). Finally, the curative effect of compounds no-radiation (fundamental state) and ration drugs were evaluated by oral drug administration of this drugs in BALB/c mice and chloroquine was used as positive control. This curative effect was determined daily by the parasitemia percentage. The results showed that both compounds were cytotoxic in fundamental state. Furthermore, cytotoxic effect was increased after radiation into the Solar Simulator, and compound 2 was more cytotoxic than compound 1. Curative assays showed that both compounds in fundamental state were non effective as anti-malarial drug. However, in the curative assays in the mice treated with compound 2, when this was ration showed a survival rate of 33 % and a parasitemia percentage decrease in compare to compound 1. Although the compounds did not show a similar or better anti-malarial effect than Chloroquine, Compound 2 presented certain anti-malarial effect after solar radiation. Rev. Biol. Trop. 66(2): 880-891. Epub 2018 June 01.


Resumen La malaria representa un importante problema de salud en todo el mundo, afectando a alrededor de 198 millones de personas en 2016 según la base de datos de la OMS. Durante décadas, se ha utilizado la terapia con fármacos anti-malpricos en la lucha contra esta enfermedad y su uso incontrolado en las zonas endémicas ha desarrollado la aparición de resistencia a los fármacos. Por lo tanto, se ha surgido la necesidad de encontrar nuevos tratamientos que podrían ser utilizados como una cura alternativa para la infección por el paludismo. El objetivo de este trabajo fue evaluar dos compuestos foto-excitables: El compuesto 1, que es (2E) -3- (4-dimetilamino-fenil) -1- (4-imidazol-1-ilfenil) prop-2 1-ona) y el Compuesto 2, (1E, 4E) -1- [4- (dimetilamino) fenil] -5- (4-metoxifenil) -1,4-pentadieno-3-ona) como posibles drogas antimaláricas con la cepa ANKA de Plasmodium berghei en ratones BALB / c como modelo murino. El efecto de la citotoxicidad se evaluó mediante una proliferación celular con el ensayo de colorimetría (MTS); y la incorporación del fármaco en el parásito se evaluó in vitro con Ensayo de Inmunofluorescencia Indirecta (IFA) para determinar la localización de los fármacos en los glóbulos rojos parasitados (RBCs). Finalmente, se evaluó el efecto curativo de los compuestos sin radiación (estado fundamental) y los fármacos irradiados mediante la administración oral de los fármacos en los ratones BALB / c, y se usó cloroquina como control positivo de cura. Este efecto curativo se determinó diariamente por el porcentaje de parasitemia. Los resultados mostraron que ambos compuestos eran citotóxicos en estado fundamental. Además, el efecto citotóxico se incrementó después de la radiación en el Simulador Solar, y el compuesto 2 fue más citotóxico que el compuesto 1. Los ensayos curativos mostraron que ambos compuestos en estado fundamental no eran eficaces como fármacos antimaláricos. Sin embargo, en los ensayos curativos en los ratones tratados con el compuesto 2, cuando fue irradiado, se observó una tasa de supervivencia del 33 % y una disminución del porcentaje de parasitemia en comparación con el compuesto 1. Aunque los compuestos no mostraron un efecto similar o mejor antimalárico que la cloroquina, el compuesto 2 presentó cierto efecto antimalárico después de la radiación solar.


Assuntos
Animais , Plasmodium/efeitos dos fármacos , Dimetilaminas/farmacologia , Imidazóis/uso terapêutico , Malária/tratamento farmacológico , Radiação Solar
5.
Acta Crystallogr C Struct Chem ; 71(Pt 9): 783-7, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26322610

RESUMO

Orange rectangular blocks suitable for X-ray diffraction analysis were obtained for the previously reported [Ahmad & Bano (2011). Int. J. ChemTech Res. 3, 1470-1478] title chalcone, C15H14ClNOS. This solid-emissive chalcone exhibits a planar structure and the bond parameters are compared with related compounds already described in the literature. The determination of the structure of this chalcone is quite relevant because it will play an important role in theoretical calculations to investigate potential two-photon absorption processes and could also be useful for studying the interaction of such compounds with a biological target.

6.
Acta Crystallogr C ; 68(Pt 6): o213-5, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22669190

RESUMO

In both title compounds, C(10)H(13)BO(3)S, (I), and C(13)H(17)BO(3), (II), the molecules adopt nearly planar conformations. The crystal packing of (I) consists of a supramolecular two-dimensional network with a herringbone-like topology formed by self assembly of centrosymmetric pairs of molecules linked via dipole-dipole interactions. The crystal structure of (II) consists of a supramolecular two-dimensional network built up from centrosymmetric pairs of molecules via π-π interactions. These pairs of molecules are self-organized in an offset fashion related by a symmetry centre, generating supramolecular ribbons running along the [101] direction. Neighbouring ribbons are stacked via complementary van der Waals and hydrophobic methyl-methyl interactions.

7.
Z Naturforsch C J Biosci ; 63(11-12): 821-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19227829

RESUMO

A chloroform extract from roots of Craniolaria annua provided six new C-11 unsubstituted abietanes, 14-hydroxy-6,12-dione-7,9(11),13-abietatriene (1), 14-hydroxy-12-oxo-7,9(11),13-abietatriene (2), 6,12,14-trihydroxyabieta-5,8,11,13-tetraen-7-one (3), ar-abietatriene-12-ol-6,7-dione-14,16-oxide (4), ar-abietatriene-12,16-diol-14,16-oxide (5) and ar-abietatriene-12-ol-7-one-14,16-oxide (6), and two known compounds, ferruginol and stigmasterol. The structures of both the new and known compounds were established by spectroscopic methods. Abietane 1 gave 14-hydroxy-6-oxoferruginol (1A) upon treatment with NaBH4. Abietanes 1, 1A, 3-5 and ferruginol showed cytotoxic effects against trypomastigote and epimastigote forms of Trypanosoma cruzi and against fibroblastic Vero cells.


Assuntos
Abietanos/isolamento & purificação , Abietanos/farmacologia , Lamiaceae/química , Raízes de Plantas/química , Tripanossomicidas/isolamento & purificação , Tripanossomicidas/farmacologia , Células Vero/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Espectrofotometria
8.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 8): o1372, 2008 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-21203094

RESUMO

The asymmetric unit of the title compound, C(17)H(16)ClNO, contains two crystallographically independent mol-ecules. These mol-ecules are connected in an alternating fashion through N-H⋯O and C-H⋯O hydrogen bonds, generating one-dimensional chains of graph sets R(2) (1)(6) and C(4) along the a axis.

9.
Z Naturforsch C J Biosci ; 60(5-6): 415-20, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16042342

RESUMO

Six functionalized 1,3-dienes were synthesized using cross-coupling reactions, catalyzed by palladium complexes, between alkenylboronic acids and alpha-bromo-alpha,beta-unsaturated carbonylic compounds. Their cytotoxicity against epimastigotes of Trypanosoma cruzi and fibroblastic Vero cells was evaluated, using concentrations ranging from 100 microM to 2.5 mM in experiments with three incubation times (4, 8 and 16 h). These tests were performed using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] colorimetric bioassays and its further reduction to formazan, according to the viability of the parasites and cells. With the exception of (5E,6E)-5-benzylidene-2-methylundec-6-en-4-one, all compounds were cytotoxic to both Trypanosoma cruzi and Vero cells, however differential values of IC50 were observed for two of these compounds. A possible structure-activity relationship is discussed.


Assuntos
Alcenos/farmacologia , Antiprotozoários/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Alcenos/síntese química , Animais , Antiprotozoários/síntese química , Chlorocebus aethiops , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Células Vero
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