Search results for "PHENOLS"
showing 10 items of 766 documents
Prevention of 7-ketocholesterol-induced side effects by natural compounds
2018
Cholesterol oxidation products, also named oxysterols, can be formed either by cholesterol auto-oxidation, enzymatically or both. Among these oxysterols, 7-ketocholesterol (7KC) is mainly formed during radical attacks that take place on the carbon 7 of cholesterol. As increased levels of 7KC have been found in the tissues, plasma and/or cerebrospinal fluid of patients with major diseases, especially age-related diseases (cardiovascular diseases, eye diseases, neurodegenerative diseases), some cancers, and chronic inflammatory diseases, it is suspected that 7KC, could contribute to their development. Since 7KC, provided by the diet or endogenously formed, is not or little efficiently metabol…
Prevention by Dietary Polyphenols (Resveratrol, Quercetin, Apigenin) Against 7-Ketocholesterol-Induced Oxiapoptophagy in Neuronal N2a Cells: Potentia…
2020
The Mediterranean diet is associated with health benefits due to bioactive compounds such as polyphenols. The biological activities of three polyphenols (quercetin (QCT), resveratrol (RSV), apigenin (API)) were evaluated in mouse neuronal N2a cells in the presence of 7-ketocholesterol (7KC), a major cholesterol oxidation product increased in patients with age-related diseases, including neurodegenerative disorders. In N2a cells, 7KC (50 µ
Phenols content and 2-D electrophoresis protein pattern: a promising tool to monitor Posidonia meadows health state
2007
Abstract Background The endemic seagrass Posidonia oceanica (L.) Delile colonizes soft bottoms producing highly productive meadows that play a crucial role in coastal ecosystems dynamics. Human activities and natural events are responsible for a widespread meadows regression; to date the identification of "diagnostic" tools to monitor conservation status is a critical issue. In this study the feasibility of a novel tool to evaluate ecological impacts on Posidonia meadows has been tested. Quantification of a putative stress indicator, i.e. phenols content, has been coupled to 2-D electrophoretic protein analysis of rhizome samples. Results The overall expression pattern from Posidonia rhizom…
(o-Hydroxyphenyl)methylphosphonic Acids: Spectrophotometric determination of their pKavalues and of the deprotonation sequence
1993
UV/VIS Absorption spectra of nitrosubsituted (o-hydroxyphenyl)methylphosphonic acids (o-(phosphonomethyl)phenols) were measured as a function of pH at 25° in 0.1M NaClo4 solutions. Computational treatment of the whole set of optical density data between 200 and 500 nm resulted in the determination of the dissociation constants of these polyacids and also of the individual electronic spectra of all the species involved in the deprotonation sequence. The spectral behavior gives information on the structure of the anions formed and consequently the order of the subsequent deprotonation steps could be deduced. For the (2-hydroxy-3-nitro(or 5-nitro)phenyl)methylphosphonic acid and the 2-hydroxy-…
Estudio de perfilación de metabolitos secundarios de extractos vegetales obtenidos mediante técnicas y estrategias no convencionales para el desarrol…
2022
En esta tesis doctoral se desarrolló en el entorno de la economía verde y el reciclaje de residuos alimentarios estudiando diferentes técnicas de extracción no convencionales. En primer lugar, se aislaron polifenoles de matrices complejas producto del desperdicio de alimentos, como son las hojas de Moringa oleifera, mediante extracción asistida por ultrasonidos (UAE). El enfoque de diseño experimental permitió optimizar las mejores condiciones de extracción (MeOH:H2O 50:50, v/v, proporcion 1:60 Sólido/Líquido (S/L), 60°C, 60 min) para obtener un contenido fenólico total (TPC) de 13,4 mg expresados como equivalentes de ácido gálico (GAE)/g de materia seca. Por lo tanto, la caracterización y …
Development of a high performance thin layer chromatography method for the rapid qualification and quantification of phenolic compounds and abscisic …
2019
Honey is a natural product with a complex chemical composition consisting of sugars and other bioactive compounds. It is important in many traditional systems of medicine, exhibiting interesting bioactivities, in particular antimicrobial, anti-inflammatory and antioxidant effects. Authentication of botanical origin of honeys is particularly important in this context. Therefore, methods for quality control of honey and detection of its adulteration are very important. A HPTLC method for the quantitative determination of phenolic compounds in honey was developed for the first time. Seven phenolic compounds were detected and determined quantitatively in lime and acacia honey samples. The obtai…
Machine learning-based models to predict modes of toxic action of phenols to Tetrahymena pyriformis.
2017
The phenols are structurally heterogeneous pollutants and they present a variety of modes of toxic action (MOA), including polar narcotics, weak acid respiratory uncouplers, pro-electrophiles, and soft electrophiles. Because it is often difficult to determine correctly the mechanism of action of a compound, quantitative structure-activity relationship (QSAR) methods, which have proved their interest in toxicity prediction, can be used. In this work, several QSAR models for the prediction of MOA of 221 phenols to the ciliated protozoan Tetrahymena pyriformis, using Chemistry Development Kit descriptors, are reported. Four machine learning techniques (ML), k-nearest neighbours, support vector…
Prediction of acute toxicity of phenol derivatives using multiple linear regression approach for Tetrahymena pyriformis contaminant identification in…
2016
In this article, the modeling of inhibitory grown activity against Tetrahymena pyriformis is described. The 0-2D Dragon descriptors based on structural aspects to gain some knowledge of factors influencing aquatic toxicity are mainly used. Besides, it is done by some enlarged data of phenol derivatives described for the first time and composed of 358 chemicals. It overcomes the previous datasets with about one hundred compounds. Moreover, the results of the model evaluation by the parameters in the training, prediction and validation give adequate results comparable with those of the previous works. The more influential descriptors included in the model are: X3A, MWC02, MWC10 and piPC03 wit…
Predictive modeling of aryl hydrocarbon receptor (AhR) agonism
2020
Abstract The aryl hydrocarbon receptor (AhR) plays a key role in the regulation of gene expression in metabolic machinery and detoxification systems. In the recent years, this receptor has attracted interest as a therapeutic target for immunological, oncogenic and inflammatory conditions. In the present report, in silico and in vitro approaches were combined to study the activation of the AhR. To this end, a large database of chemical compounds with known AhR agonistic activity was employed to build 5 classifiers based on the Adaboost (AdB), Gradient Boosting (GB), Random Forest (RF), Multilayer Perceptron (MLP) and Support Vector Machine (SVM) algorithms, respectively. The built classifier…
Effect of methyl jasmonate in gene expression, and in hormonal and phenolic profiles of holm oak embryogenic lines before and after infection with Ph…
2022
The dieback syndrome affecting Quercus ilex and other oak species impels the search for tolerant plant genotypes, as well as methods of plant immunization against such infections. Elicitation treatments can be an effective strategy to activate plant defense response and embryogenic lines represent a promising tool to generate new tolerant genotypes and also to study early markers involved in defense response. The aim of the presented work was to investigate changes in gene expression, and in hormonal and phenolic profiles induced in three holm oak embryogenic lines (ELs) elicited with methyl jasmonate (MeJA) before and after infection with the oomycete Phytophthora cinnamomi, which is the m…