Group Rings
Mostrando 1-12 de 153 artigos, teses e dissertações.
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1. RING CURRENT IN ANTHRACENE AND PHENANTHRENE: CORRECTION TO HÜCKEL PARAMETERS
Excessive degeneracy in the ground state of the π-electron energy levels of anthracene was removed using the Hückel method by correcting the Coulomb integral of the four central carbon atoms. A further correction to the resonance integral was proposed based on the ring-current model, which describes the π-ring current flow along the molecule’s perimeter
Química Nova. Publicado em: 2022
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2. Crystal Structure and Hirshfeld Surface Analysis of 1,4-Pentadien-3-one, (1E,4E)-1,5-diphenyl-2-(2,4-dinitrophenyl)hydrazone
The compound 1,4-pentadien-3-one,(1E,4E)-1,5-diphenyl-2-(2,4-dinitrophenyl)hydrazone presents the molecular formula C23H18N4O4 and was prepared in an undergraduate laboratory. The hydrazone was synthesized from the condensation between dibenzalacetone and 2,4-dinitrophenylhydrazine (DNPH) and crystallized employing water/acetone liquid-liquid diffusion. The
J. Braz. Chem. Soc.. Publicado em: 2021-02
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3. Unexpected Rearrangement and Aromatization on Dehydration Reaction of the Bioactive Diterpenequinone 7α-Hydroxyroyleanone
7a-Hydroxyroyleanone is a bioactive diterpene isolated from leaves of Tetradenia riparia, active against tuberculosis and T. cruzi. In order to use this compound as starting material for the synthesis of compounds with enhanced bioactivity we aimed the dehydration of the 7-alpha-hydroxyl group of royleanone. The reaction performed in acetic acid and hydrochl
J. Braz. Chem. Soc.. Publicado em: 2020-03
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4. Vasorelaxant activity and acute toxicity of the ethanolic extract of Zanthoxylum rhoifolium Lam leaves
The study evaluated the vasorelaxant effect induced by the ethanolic extract of the leaves of Zanthoxylum rhoifolium Lam (EEtOH-Zr/leaves). Wistar rats were treated with the leaf extract containing a single dose of 2,000 mg / kg, v.o. After 14 days, the animals were anesthetized for blood collection and subsequent analysis of the biochemical parameters; they
Braz. J. Pharm. Sci.. Publicado em: 30/09/2019
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5. EPOXIDATION OF JATROPHA METHYL ESTERS VIA ACIDIC ION EXCHANGE RESIN: OPTIMIZATION AND CHARACTERIZATION
Abstract Plant oils and their derivatives have been vigorously exploited as alternatives for synthesis of epoxides due to depletion of petroleum resources. In this study, crude jatropha oil (CJO) was subjected to a transesterification process to form jatropha methyl esters (JME) using peroxyacetic acid generated in situ from hydrogen peroxide and acetic acid
Braz. J. Chem. Eng.. Publicado em: 30/09/2019
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6. Analysis of the chemical reactivity of indaziflam herbicide and its metabolites through global and local reactivity descriptors
In the present work, the chemical reactivity of indaziflam N-[(1R,2S)-2,3-dihydro-2,6-dimethyl-1H-inden-1 yl]-6-[(1R)-1-16 fluoroethyl]-1,3,5-triazine-2,4-diamine so called indaziflam (IND) and its metabolites: triazine indanone (ITI), indaziflam carboxylic acid (ICA) and fluoroethyldiaminotriazine (FDAT) was analyzed. The calculations were performed at the
Quím. Nova. Publicado em: 15/08/2019
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7. Second-generation pterocarpanquinones: synthesis and antileishmanial activity
Abstract Background: Despite the development of new therapies for leishmaniasis, among the 200 countries or territories reporting to the WHO, 87 were identified as endemic for Tegumentary Leishmaniasis and 75 as endemic for Visceral Leishmaniasis. The identification of antileishmanial drug candidates is essential to fill the drug discovery pipeline for leis
J. Venom. Anim. Toxins incl. Trop. Dis. Publicado em: 17/12/2018
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8. Synthesis and Cytotoxic Evaluation of 1H-1,2,3-Triazol-1-ylmethyl-2,3-dihydronaphtho[1,2-b]furan-4,5-diones
ABSTRACT The 1,2-naphthoquinone compound was previously considered active against solid tumors. Moreover, glycosidase inhibitors such as 1,2,3-1H triazoles has been pointed out as efficient compounds in anticancer activity studies. Thus, a series of eleven 1,2-naphthoquinones tethered in C2 to 1,2,3-1H-triazoles 9a-k were designed, synthesized and their cyto
An. Acad. Bras. Ciênc.. Publicado em: 15/02/2018
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9. Decellularized Bovine Articular Cartilage Matrix Reinforced by Carboxylated-SWCNT for Tissue Engineering Application
ABSTRACT Nanotubes with their unique properties have diversified mechanical and biological applications. Due to similarity of dimensions with extracellular matrix (ECM) elements, these materials are used in designing scaffolds. In this research, Carboxylated Single-Wall Carbon Nanotubes in optimization of decellularized scaffold of bovine articular cartilage
Braz. arch. biol. technol.. Publicado em: 08/01/2018
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10. The effect of a self-constructed material on children’s physical activity during recess
ABSTRACT OBJECTIVE To analyze whether an intervention supported by free play with a self-constructed material increases the level of physical activity of students during recess. METHODS The participants were 166 children of third to sixth grade, between nine and 12 years old (average = 10.64; SS = 1.13). An experimental project was conducted with pre-test
Rev. Saúde Pública. Publicado em: 26/06/2017
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11. Role of adenylyl cyclase in reduced β-adrenoceptor-mediated vasorelaxation during maturation
Beta-adrenergic receptor (βAR)-dependent blood vessel relaxation is impaired in older animals and G protein activation has been suggested as the causative mechanism. Here, we investigated the role of βAR subtypes (β1AR, β2AR, and β3AR) and cAMP in maturation-dependent vasorelaxation impairment. Aortic rings from 15 Sprague-Dawley male rats (3 or 9 weeks
Braz J Med Biol Res. Publicado em: 04/07/2016
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12. Actividad antioxidante de los polifenoles de HYPOGYMNIA TAVARESII D. HAWKSW. & P. JAMES
Lichen substances have more than one phenolic hydroxyl group attached to one or more benzene rings, thus qualifying them as polyphenols. The secondary metabolites isolated from the lichen H. tavaresii have been studied in a bid to find compounds protective against oxidative stress and free radical-induced damage. The compounds were identified based on their
Quím. Nova. Publicado em: 2016-05