Hydroquinone Stability
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Synthesis of Antioxidant Additive from Safflower Seed Oil
Several published studies have evaluated the problems associated with the utilization of biodiesel obtained from safflower (Carthamus tinctorius L.) oil due to the low oxidative stability, caused by the high content of unsaturated fatty acids. Thus, this study aimed at the extraction of safflower seed oil and its use as an unsaturation source to obtain a syn
J. Braz. Chem. Soc.. Publicado em: 2021-01
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2. EVALUATION OF THE PHOTOCATALYTIC ACTIVITY OF SiO2@TiO2 HYBRID SPHERES IN THE DEGRADATION OF METHYLENE BLUE AND HYDROXYLATION OF BENZENE: KINETIC AND MECHANISTIC STUDY
Abstract Silica spheres coated with titania (SiO2@TiO2) were synthesized using chitosan as template. The N2 adsorption/desorption isotherms of the spheres point to meso and macroporous characteristics and the elemental mapping by EDS shows uniform distribution of Ti on the surface of the silica spheres, leading to formation of an amorphous structure (XRD). T
Braz. J. Chem. Eng.. Publicado em: 13/01/2020
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3. Determination of Catechol and Hydroquinone by Using Perilla frutescens Activated Carbon Modified Glassy Carbon Electrode
High specific surface area activated carbon prepared by Perilla frutescens (PFHSAAC) was modified on the surface of the glassy carbon electrode (GCE) by drop-coating method to construct a PFHSAAC/GCE. The electrochemical properties of the modified electrode were investigated in detail by some electrochemical methods such as cyclic voltammetry (CV), different
J. Braz. Chem. Soc.. Publicado em: 2020-01
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4. N-Acetyl-cysteine Increases Chemical Stability of Hydroquinone in Pharmaceutical Formulations: a Theoretical and Experimental Approach
In this study, the chemistry stability of hydroquinone (HQ) was evaluated according to its effects in redox properties and compared to kojic acid (KA). The HQ oxidation was more inhibited by N-acetylcysteine (NAC) than ascorbic acid (AA). These results were elucidated using theoretical methods at the DFT/B3LYP level of theory. All electronic parameters were
J. Braz. Chem. Soc.. Publicado em: 2018-03
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5. Desenvolvimento de método eletroanalítico para determinação direta de cobre em biodiesel e monitoramento do metal em biodiesel exposto a condições simuladas de armazenamento
A simple, effective and low cost for copper determination in biodiesel, without decomposition of the sample is presented. The samples of biodiesel were diluted in a hydro-ethanolic solution (containing HCl as supporting electrolyte) generating a homogeneous ternary system (water-ethanol-biodiesel) in which copper was detected directly using potentiometric st
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/09/2011
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6. COMPORTAMENTO MOLECULAR DA HIDROQUINONA EM PREPARAÇÕES FARMACÊUTICAS
There are many pathological changes of skin color classified into hereditary and acquired hyper-pigmentation. The depigmetant drugs mostly used in the treatment of skin hyperpigmentation are zelaic acid, phytic acid, ascorbic acid, kojic acid, tretinoin and hydroquinone. However, hydroquinone is mainly used in masterful formulations; primarily in the handlin
Publicado em: 2010
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7. Synthesis, characterization and study of catalytical properties of mixed layered hydroxides containing Cu(II)/Mg(II)/Al(III) / Síntese, caracterização e estudo de propriedades catalíticas de hidróxidos mistos lamelares contendo Cu(II)/Mg(II)/AI(III)
In this work it was investigated the preparation and spectroscopic characterization of layered hydroxides of composition [Mg3-xCuxAl(OH)8](CO3)0.5.yH2O (x = 0.3; 0.6; 0.9; 1.2; 1.5; 1.8; 2.1; 2.4; 2.7 and 3.0), as well the reactivity of these materials towards phenol hydroxylation, using hydrogen peroxide as oxidizing agent. The solids had been prepared thro
Publicado em: 2005
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8. ObtenÃÃo, caracterizaÃÃo e avaliaÃÃo microbiolÃgica de uma nova forma farmacÃutica contendo hidroquinona
Hydroquinone (HQ) is a drug reported to possess manifold biological activities, such as depigmenting, antimicrobial and antitumour properties. The PluronicLecithin Organogel (PLOme) is a phospholipidic microemulsion particularly implied when a high cutaneous permeability and systemic absorption of a drug is suitable. Once that HQ is highly unstable i
Publicado em: 2003
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9. Vitamin K-dependent carboxylation of the carboxylase
Vitamin K-dependent (VKD) proteins require modification by the VKD-γ-glutamyl carboxylase, an enzyme that converts clusters of glus to glas in a reaction that requires vitamin K hydroquinone, for their activity. We have discovered that the carboxylase also carboxylates itself in a reaction dependent on vitamin K. When pure human recombinant carboxylase was
The National Academy of Sciences.