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[en] This work investigates the role of oleanolic acid (OA), isolated from the olive (Olea europaea L.) leaf, as a radical scavenger and inhibitor of the hydrolyzing enzymes of dietary carbohydrates. New evidence is provided showing that OA may capture 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) and peroxyl radicals, and also exert a strong and non-competitive inhibition of α-glucosidase (IC50 10.11 ± 0.30 µM). The kinetic and spectrometric analyses performed indicate that OA interacts with this enzyme inside a hydrophobic pocket, through an endothermic and non spontaneous process of a hydrophobic nature. These are two possible mechanisms by which OA may facilitate a better control of post-prandial hyperglycaemia and oxidative stress, so contributing to preserving insulin signalling. Obesity, insulin resistance and Type 2 Diabetes Mellitus are considered the first pandemics of the 21st century. In this sense, OA might be used in future preventive and therapeutic strategies, as an ingredient in new drugs and functional foods.
[es]Este trabajo estudia el papel del ácido oleanólico (OA), aislado de la hoja de olivo, como secuestrador de radicales libres e inhibidor de enzimas implicados en la hidrolisis de los carbohidratos de la dieta, dos mecanismos por los que el triterpeno podría mitigar la hiperglicemia postprandial y el estrés oxidativo. Se aportan nuevas evidencias que muestran que el OA puede capturar radicales ácido 2,2’-azino-bis-(3-etilbenzotiazolín)-6-sulfónico y peroxilo, y que ejerce una potente inhibición nocompetitiva de α-glucosidasa (IC50 10.11±0.30 µM). El análisis cinético y espectrométrico llevado a cabo indica que OA interacciona con este enzima en el interior de un bolsillo hidrofóbico, mediante un proceso endotérmico no espontáneo, de naturaleza hidrofóbica. Estos son dos posibles mecanismos por los cuales el OA puede facilitar un mejor control de la hiperglucemia postprandial y el estrés oxidativo, lo que contribuye a preservar la señalización de la insulina. La obesidad, la resistencia a la insulina y la diabetes mellitus tipo 2 se consideran la primera pandemia del siglo XXI. En este sentido, el OA podría ser utilizado en futuras estrategias preventivas y terapéuticas, como ingrediente de nuevos fármacos y alimentos funcionales.
[en] For the clarification of the mechanism of interaction of oleic acid withminerals the high profile has studying process of complexing of ions ofoleates with metal cations constituent of mineral and for that by authors waspassed several experiments
[en] The structuralization of magnetic particles after illumination was experimentally observed in two types of a magnetic fluid based on mineral oil with the magnetite particles covered by monolayer surfactant and kerosene-based magnetic fluid sterically stabilized by a double layer consisting of oleic acid and dodecylbenzensulphonic acid (DBS). This contribution presents a detailed theoretical description of the thermodiffusion process in magnetic fluids, simulation of the structuralization in magnetic fluid with a negative Soret constant, and confirmaton of the negative value of this constant for a kerosene-based magnetic fluid.
[en] Estolides are a developing class of natural and synthetic compounds that have been synthesized from hydroxy oils like castor and lesquerella or by the condensation of fatty acids across the olefin of a second fatty acid. Castor and lesquerella estolides are derived from either their triglycerides or their free fatty acids utilizing their hydroxyl moiety to establish the estolide bond. The triglyceride estolides have pour points of 9 to -36 degrees centigrade but suffer poor oxidative stability with RPVOT times of 29 - 52 minutes even with 1% of an anti-oxidant package incorporated into the samples. In contrast to the triglyceride estolides of castor and lesquerella, the estolides from lesquerolic and ricinoleic acids have very good pour points of -36 to - 54 degrees centigrade. Estolides derived from the acid catalyzed condensation of oleic acid with a variety of fatty acids can be made in good yield and posses a wide range of physical properties. Of particular interest are the saturated capped estolides of oleic that have both good low temperature properties (pour point -5 to -39 degrees centigrade) and good oxidative stability. Estolides from meadow foam fatty acids do not have good low temperature properties but have been extensively used in cosmetics where they provide good moisturizing properties. (Author).
[en] Pequi is an indigenous word that means “thorny covering” and is used to describe fruits from the Caryocar spp. These fruits are widely consumed as food and used in traditional medicine by Brazilians in the savannah (Cerrado biome) and the Amazon region. The fruit is rich in lipids, mainly oleic acid, and other bioactive substances including carotenoids, phenolics, and tocopherols. The oil extracted from the pulp or “almond” (seed) has a high local socioeconomic impact and is associated with nutritional and therapeutic benefits. A wide array of health benefits such as antioxidant, anti-inflammatory, antitumor, and antimicrobial effects, improved cardiac function, as well as an increased lymphocyte-dependent immunity have been attributed to the pequi fruit, especially its pulp. This review provides a comprehensive overview on the edible parts of pequi fruits (pulp and almond), more specifically the oil produced from these parts, as a source of functional compounds with biological activity. Moreover, it considers the differences among the three more commercially-important species from the genus Caryocar.
[es]Pequi es una palabra indígena que significa “piel espinosa” y es utilizada para describir los frutos de Caryocar spp. Estos frutos son ampliamente consumidos como alimentos y son utilizados en la medicina popular por los brasileños ubicados en el Savannah (bioma Cerrado) y en la región amazónica. La fruta es rica en grasas, ácido oleico y otros bioactivos, incluyendo carotenoides, fenoles y tocoferoles. El aceite procedente de la pulpa o de la almendra (semilla) tiene un importante impacto socioeconómico local y está asociado con beneficios nutricionales y terapéuticos. Una amplia gama de beneficios para la salud tales como antioxidante, antiinflamatorio, antitumoral, antimicrobiano, mejora de la función cardíaca, así como el aumento de la inmunidad linfocitaria han sido atribuidas a la fruta, especialmente a su pulpa. Esta revisión proporciona una descripción exhaustiva sobre las partes comestibles de la fruta del pequi (pulpa y almendra), más específicamente del aceite producido a partir de estas partes, como una fuente de compuestos funcionales con actividad biológica. Además se consideran las diferencias encontradas entre las tres especies comerciales más importantes del género Caryocar.
[en] Sapphire is widely used in production of optical windows for various devices due to its mechanical and optical properties. However, during operation the surface can be affected by fats, oils, and other organic contaminations. Therefore, it is important to improve the oleophobic properties of sapphire windows. In this study, we investigate the interaction of a supersmooth sapphire surface with oleic acid droplets, which imitate human finger printing. It is established that chemical–mechanical polishing with additional annealing in air, which leads to the formation of an atomically smooth sapphire surface, makes it possible to significantly improve the oleophobic properties of the surface. The results are analyzed using the Ventsel–Deryagin homogeneous wetting model.
[en] The destruction of cancerogenic polycyclic hydrocarbons in oleic acid as a function of its oxidation degree was studied. Ionizing radiation was used as a factor initiating autooxidation. The effect of antioxidants on the cancerogens destruction was investigated. A correlation between the cancerogen destruction value and the oxidation rate of oleic acid was obtained. A mechanism of antioxidants action was discussed
[en] The aim of this study was to evaluate the nutritional quality, phenolic compounds, fatty acid and antioxidant activity in vitro as well as a toxicological screening of A. muricata seed oil in vivo. The chemical composition and quantification of phenolic compounds were determined by the Adolfo Lutz Institute normative. The antioxidant activity was evaluated by DPPH, FRAP and ABTS methods. The oil was extracted by chloroform/ methanol and precipitated crude (AmPtO) and supernatant oils (AmSO) were obtained. The fatty acid profile was evaluated by gas chromatography and total compounds by HPLC-DAD. BALB/C mice received AmPtO and AmSO (0.5 and 1.0mL·Kg-1) for 14 days. Toxicity parameters were assessed. The major fatty acids in the oil were oleic (39.2%) and linoleic (33%). HPLC-DAD suggested the presence of acetogenins (annonacin: 595 [M-H]-), with a greater presence in AmPtO. The AmPtO group showed toxicity, which may be related to the acetogenin content in AmPtO. The AmSO group showed no toxicity and this oil has potential for food or medicinal use.
[es]El objetivo de este estudio fue evaluar la calidad nutricional, compuestos fenólicos, ácidos grasos, actividad antioxidante in vitro y evaluación toxicológica del aceite de las semillas de la Annona muricata. La composición química y los compuestos fenólicos se determinaron de acuerdo con las normas del Instituto Adolfo Lutz y la actividad antioxidante por métodos de DPPH, FRAP y ABTS. El aceite fue extraído con cloroformo/metanol obteniéndose un precipitado crudo (AmPtO) y un aceite sobrenadante (AmSO). El perfil de ácidos grasos fue evaluado por cromatografía gaseosa y los compuestos fitoquímicos mediante HPLCDAD. BALB/C recibieron AmPtO y AmSO (0,5 y 1,0 mL·kg-1) durante 14 días. Se evaluaron los parámetros bioquímicos e histopatológicos. Los ácidos grasos principales fueron oleico (39,2%) y linoleico (33%). HPLCDAD indicó la presencia de acetogeninas, particularmente anonacina (595 [M-H]- ), principalmente en AMPtO. AmPtO presentó toxicidad y esto puede estar relacionado con las acetogeninas. AmSO no presentó toxicidad y tiene potencial para la alimentación o uso medicinal.
[en] Hard magnetic NdFeB submicron and nanoflakes were successfully prepared by surfactant-assisted ball milling at room temperature (SABMRT) and low temperature (SABMLT) by using oleic acid (OA), oleylamine (OLA) and trioctylamine (TOA) as surfactant, respectively. Among the surfactants used, OA and OLA have similar effects on the morphology of the NdFeB nanoflakes milled at both room and low temperature. In the case of TOA, irregular micron-sized particles and submirco/nanoflakes were obtained for the NdFeB powders prepared by SABMRT and SABMLT, respectively. Samples prepared by SABMLT show better crystallinity and better degree of grain alignment than that prepared by SABMRT with the same surfactant. Comparing with the samples milled at RT, higher coercivity and larger remanence ratio were achieved in the NdFeB samples prepared at LT. The amounts of residual surfactants in final NdFeB powders were also calculated, which reveals that the final NdFeB powders milled at LT possess lower amount of residual surfactants than those milled at RT. It was found that lowering milling temperature of SABM would be a promising way for fabricating permanent magnetic materials with better hard magnetic properties. (paper)
[en] In some cell types, gap junctional intercellular communication (GJIC) is associated with tight junctions. The present study was performed to determine the roles of GJIC in regulation of the barrier function of tight junctions. Caco-2 human colonic cells were used as a monolayer model, and barrier function was monitored by measuring mannitol permeability and transepithelial electrical resistance (TER). The monolayers were chemically disrupted by treatment with oleic acid and taurocholic acid. Western blotting analyses were performed to evaluate the protein levels of connexins, which are components of gap junctional intercellular channels. Cx26 expression was detected in preconfluent Caco-2 cells, and its level increased gradually after the monolayer reached confluency. These results prompted us to examine whether overexpression of Cx26 affects barrier function. Monolayers of Caco-2 cells stably expressing Cx26 showed significantly lower mannitol permeability and higher TER than mock transfectants when the monolayers were chemically disrupted. The levels of claudin-4, an important component of tight junctions, were significantly increased in the stable Cx26 transfectant. These results suggest that Cx26-mediated GJIC may play a crucial role in enhancing the barrier function of Caco-2 cell monolayers